l3 (10oct23)

git-svn-id: svn://tug.org/texlive/trunk@68507 c570f23f-e606-0410-a88d-b1316a301751

27 files changed, 1751 insertions, 1576 deletions

diff --git a/Master/texmf-dist/tex/latex/l3backend/l3backend-dvipdfmx.def b/Master/texmf-dist/tex/latex/l3backend/l3backend-dvipdfmx.def
index 4f3eb45eb97..62fb5d14cfe 100644
--- a/Master/texmf-dist/tex/latex/l3backend/l3backend-dvipdfmx.def
+++ b/Master/texmf-dist/tex/latex/l3backend/l3backend-dvipdfmx.def
@@ -26,7 +26,7 @@
 %% 
 %% File: l3backend-basics.dtx
 \ProvidesExplFile
-  {l3backend-dvipdfmx.def}{2023-04-19}{}
+  {l3backend-dvipdfmx.def}{2023-10-10}{}
   {L3 backend support: dvipdfmx}
 \cs_if_exist:NTF \__kernel_dependency_version_check:nn
   {
@@ -45,7 +45,6 @@
 \cs_new_eq:NN \__kernel_backend_literal:e \tex_special:D
 \cs_new_protected:Npn \__kernel_backend_literal:n #1
   { \__kernel_backend_literal:e { \exp_not:n {#1} } }
-\cs_generate_variant:Nn \__kernel_backend_literal:n { x }
 \cs_if_exist:NTF \@ifl@t@r
   {
     \@ifl@t@r \fmtversion { 2020-10-01 }
@@ -58,7 +57,7 @@
   { \cs_new_eq:NN \__kernel_backend_first_shipout:n \use:n }
 \cs_new_protected:Npn \__kernel_backend_literal_pdf:n #1
   { \__kernel_backend_literal:n { pdf:literal~ #1 } }
-\cs_generate_variant:Nn \__kernel_backend_literal_pdf:n { x }
+\cs_generate_variant:Nn \__kernel_backend_literal_pdf:n { e }
 \cs_new_protected:Npn \__kernel_backend_literal_page:n #1
   { \__kernel_backend_literal:n { pdf:literal~direct~ #1 } }
 \cs_new_protected:Npn \__kernel_backend_scope_begin:
@@ -82,7 +81,7 @@
 \msg_new:nnn { color } { unknown-named-color }
   { Named~color~'#1'~is~not~known. }
 \prop_new:N \g__color_backend_colorant_prop
-\cs_new:Npx \__color_backend_devicen_colorants:n #1
+\cs_new:Npe \__color_backend_devicen_colorants:n #1
   {
     \exp_not:N \tl_if_blank:nF {#1}
       {
@@ -108,7 +107,7 @@
     \__color_backend_devicen_colorants:w
   }
 \cs_new_protected:Npn \__color_backend_select_separation:nn #1#2
-  { \__kernel_backend_literal:x { pdf : bc ~ \pdf_object_ref:n {#1} ~ [ #2 ] } }
+  { \__kernel_backend_literal:e { pdf : bc ~ \pdf_object_ref:n {#1} ~ [ #2 ] } }
 \cs_new_eq:NN \__color_backend_select_devicen:nn \__color_backend_select_separation:nn
 \cs_new_eq:NN \__color_backend_select_iccbased:nn \__color_backend_select_separation:nn
 \cs_new_protected:Npn \__color_backend_init_resource:n #1
@@ -116,7 +115,7 @@
   }
 \cs_new_protected:Npn \__color_backend_separation_init:nnnnn #1#2#3#4#5
   {
-    \pdf_object_unnamed_write:nx { dict }
+    \pdf_object_unnamed_write:ne { dict }
       {
         /FunctionType ~ 2
         /Domain ~ [0 ~ 1]
@@ -124,19 +123,19 @@
         /C0 ~ [#4] ~
         /C1 ~ [#5] /N ~ 1
       }
-    \exp_args:Nx \__color_backend_separation_init:nn
+    \exp_args:Ne \__color_backend_separation_init:nn
       { \str_convert_pdfname:n {#1} } {#2}
     \__color_backend_init_resource:n { color \int_use:N \g__color_model_int }
   }
 \cs_new_protected:Npn \__color_backend_separation_init:nn #1#2
   {
-    \use:x
+    \use:e
       {
         \pdf_object_new:n { color \int_use:N \g__color_model_int }
         \pdf_object_write:nnn { color \int_use:N \g__color_model_int } { array }
           { /Separation /#1 ~ #2 ~ \pdf_object_ref_last: }
       }
-    \prop_gput:Nnx \g__color_backend_colorant_prop { /#1 }
+    \prop_gput:Nne \g__color_backend_colorant_prop { /#1 }
       { \pdf_object_ref_last: }
   }
 \cs_new_protected:Npn \__color_backend_separation_init_CIELAB:nnn #1#2#3
@@ -144,7 +143,7 @@
     \pdf_object_if_exist:nF { __color_illuminant_CIELAB_ #1 }
       {
         \pdf_object_new:n { __color_illuminant_CIELAB_ #1 }
-        \pdf_object_write:nnx { __color_illuminant_CIELAB_ #1 } { array }
+        \pdf_object_write:nne { __color_illuminant_CIELAB_ #1 } { array }
           {
             /Lab ~
             <<
@@ -163,7 +162,7 @@
   }
 \cs_new_protected:Npn \__color_backend_devicen_init:nnn #1#2#3
   {
-    \pdf_object_unnamed_write:nx { stream }
+    \pdf_object_unnamed_write:ne { stream }
       {
         {
           /FunctionType ~ 4 ~
@@ -185,7 +184,7 @@
         }
         { {#3} }
      }
-    \use:x
+    \use:e
       {
         \pdf_object_new:n { color \int_use:N \g__color_model_int }
         \pdf_object_write:nnn { color \int_use:N \g__color_model_int } { array }
@@ -210,7 +209,7 @@
     \pdf_object_if_exist:nF { __color_icc_ #1 }
       {
         \pdf_object_new:n { __color_icc_ #1 }
-        \pdf_object_write:nnx { __color_icc_ #1 } { fstream }
+        \pdf_object_write:nne { __color_icc_ #1 } { fstream }
           {
             {
               /N ~ \exp_not:n { #2 } ~
@@ -219,7 +218,7 @@
             {#1}
           }
       }
-    \pdf_object_unnamed_write:nx { array }
+    \pdf_object_unnamed_write:ne { array }
       { /ICCBased ~ \pdf_object_ref:n { __color_icc_ #1 } }
     \__color_backend_init_resource:n { color \int_use:N \g__color_model_int }
   }
@@ -234,7 +233,7 @@
             {#1}
           }
       }
-    \pdf_object_unnamed_write:nx { array }
+    \pdf_object_unnamed_write:ne { array }
       { /ICCBased ~ \pdf_object_ref:n { __color_icc_ #1 } }
     \__color_backend_init_resource:n { Default #2 }
   }
@@ -250,12 +249,12 @@
 \cs_new_eq:NN \__color_backend_stroke_rgb:n  \__color_backend_stroke:n
 \cs_new_protected:Npn \__color_backend_fill_separation:nn #1#2
   {
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       { pdf : bc ~ fill ~ \pdf_object_ref:n {#1} ~ [ #2 ] }
   }
 \cs_new_protected:Npn \__color_backend_stroke_separation:nn #1#2
   {
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       { pdf : bc ~ stroke ~ \pdf_object_ref:n {#1} ~ [ #2 ] }
   }
 \cs_new_eq:NN \__color_backend_fill_devicen:nn \__color_backend_fill_separation:nn
@@ -266,7 +265,7 @@
 \cs_new_protected:Npn \__box_backend_clip:N #1
   {
     \__kernel_backend_scope_begin:
-    \__kernel_backend_literal_pdf:x
+    \__kernel_backend_literal_pdf:e
       {
         0~
         \dim_to_decimal_in_bp:n { -\box_dp:N #1 } ~
@@ -283,7 +282,7 @@
 \cs_new_protected:Npn \__box_backend_rotate_aux:Nn #1#2
   {
     \__kernel_backend_scope_begin:
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       {
         x:rotate~
         \fp_compare:nNnTF {#2} = \c_zero_fp
@@ -296,7 +295,7 @@
 \cs_new_protected:Npn \__box_backend_scale:Nnn #1#2#3
   {
     \__kernel_backend_scope_begin:
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       {
         x:scale~
         \fp_eval:n { round ( #2 , 5 ) } ~
@@ -307,7 +306,7 @@
   }
 %% File: l3backend-draw.dtx
 \cs_new_eq:NN \__draw_backend_literal:n \__kernel_backend_literal_pdf:n
-\cs_generate_variant:Nn \__draw_backend_literal:n { x }
+\cs_generate_variant:Nn \__draw_backend_literal:n { e }
 \cs_new_protected:Npn \__draw_backend_begin:
   { \__draw_backend_scope_begin: }
 \cs_new_protected:Npn \__draw_backend_end:
@@ -316,17 +315,17 @@
 \cs_new_eq:NN \__draw_backend_scope_end: \__kernel_backend_scope_end:
 \cs_new_protected:Npn \__draw_backend_moveto:nn #1#2
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~ m }
   }
 \cs_new_protected:Npn \__draw_backend_lineto:nn #1#2
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~ l }
   }
 \cs_new_protected:Npn \__draw_backend_curveto:nnnnnn #1#2#3#4#5#6
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       {
         \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~
         \dim_to_decimal_in_bp:n {#3} ~ \dim_to_decimal_in_bp:n {#4} ~
@@ -336,7 +335,7 @@
  }
 \cs_new_protected:Npn \__draw_backend_rectangle:nnnn #1#2#3#4
   {
-     \__draw_backend_literal:x
+     \__draw_backend_literal:e
       {
         \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~
         \dim_to_decimal_in_bp:n {#3} ~ \dim_to_decimal_in_bp:n {#4} ~
@@ -356,24 +355,24 @@
   { \__draw_backend_literal:n { s } }
 \cs_new_protected:Npn \__draw_backend_fill:
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { f \bool_if:NT \g__draw_draw_eor_bool * }
   }
 \cs_new_protected:Npn \__draw_backend_fillstroke:
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { B \bool_if:NT \g__draw_draw_eor_bool * }
   }
 \cs_new_protected:Npn \__draw_backend_clip:
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { W \bool_if:NT \g__draw_draw_eor_bool * }
   }
 \cs_new_protected:Npn \__draw_backend_discardpath:
   { \__draw_backend_literal:n { n } }
 \cs_new_protected:Npn \__draw_backend_dash_pattern:nn #1#2
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       {
         [
           \exp_args:Nf \use:n
@@ -386,11 +385,11 @@
   { ~ \dim_to_decimal_in_bp:n {#1} }
 \cs_new_protected:Npn \__draw_backend_linewidth:n #1
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { \dim_to_decimal_in_bp:n {#1} ~ w }
   }
 \cs_new_protected:Npn \__draw_backend_miterlimit:n #1
-  { \__draw_backend_literal:x { #1 ~ M } }
+  { \__draw_backend_literal:e { #1 ~ M } }
 \cs_new_protected:Npn \__draw_backend_cap_butt:
   { \__draw_backend_literal:n { 0 ~ J } }
 \cs_new_protected:Npn \__draw_backend_cap_round:
@@ -410,20 +409,20 @@
   }
 \cs_new_protected:Npn \__draw_backend_cm_aux:nnnn #1#2#3#4
   {
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       {
         x:rotate~
         \fp_compare:nNnTF {#1} = \c_zero_fp
           { 0 }
           { \fp_eval:n { round ( -#1 , 5 ) } }
       }
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       {
         x:scale~
         \fp_eval:n { round ( #2 , 5 ) } ~
         \fp_eval:n { round ( #3 , 5 ) }
       }
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       {
         x:rotate~
         \fp_compare:nNnTF {#4} = \c_zero_fp
@@ -433,7 +432,7 @@
   }
 \cs_new_protected:Npn \__draw_backend_cm_decompose:nnnnN #1#2#3#4#5
   {
-    \use:x
+    \use:e
       {
         \__draw_backend_cm_decompose_auxi:nnnnN
           { \fp_eval:n { (#1 + #4) / 2 } }
@@ -445,7 +444,7 @@
   }
 \cs_new_protected:Npn \__draw_backend_cm_decompose_auxi:nnnnN #1#2#3#4#5
   {
-    \use:x
+    \use:e
       {
         \__draw_backend_cm_decompose_auxii:nnnnN
           { \fp_eval:n { 2 * sqrt ( #1 * #1 + #4 * #4 ) } }
@@ -457,7 +456,7 @@
   }
 \cs_new_protected:Npn \__draw_backend_cm_decompose_auxii:nnnnN #1#2#3#4#5
   {
-    \use:x
+    \use:e
       {
         \__draw_backend_cm_decompose_auxiii:nnnnN
           { \fp_eval:n { ( #4 - #3 ) / 2 } }
@@ -522,7 +521,7 @@
 \int_new:N \g__graphics_track_int
 \cs_new_protected:Npn \__graphics_backend_include_eps:n #1
   {
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       {
         PSfile = #1 \c_space_tl
         llx = \dim_to_decimal_in_bp:n \l__graphics_llx_dim \c_space_tl
@@ -541,7 +540,7 @@
   { \__graphics_backend_include_auxi:nn {#1} { epdf } }
 \cs_new_protected:Npn \__graphics_backend_include_auxi:nn #1#2
   {
-    \__graphics_backend_include_auxii:xnn
+    \__graphics_backend_include_auxii:enn
       {
         \tl_if_empty:NF \l__graphics_pagebox_tl
           { : \l__graphics_pagebox_tl }
@@ -558,17 +557,17 @@
   {
     \int_if_exist:cTF { c__graphics_ #2#1 _int }
       {
-        \__kernel_backend_literal:x
+        \__kernel_backend_literal:e
           { pdf:usexobj~@graphic \int_use:c { c__graphics_ #2#1 _int } }
       }
       { \__graphics_backend_include_auxiii:nnn {#2} {#1} {#3} }
   }
-\cs_generate_variant:Nn \__graphics_backend_include_auxii:nnn { x }
+\cs_generate_variant:Nn \__graphics_backend_include_auxii:nnn { e }
 \cs_new_protected:Npn \__graphics_backend_include_auxiii:nnn #1#2#3
   {
     \int_gincr:N \g__graphics_track_int
     \int_const:cn { c__graphics_ #1#2 _int } { \g__graphics_track_int }
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       {
         pdf:#3~
         @graphic \int_use:c { c__graphics_ #1#2 _int } ~
@@ -601,9 +600,9 @@
   { \cs_new_eq:NN \__graphics_backend_get_pagecount:n \__graphics_get_pagecount:n }
 %% File: l3backend-pdf.dtx
 \box_new:N \l__pdf_internal_box
-\cs_new_protected:Npx \__pdf_backend:n #1
+\cs_new_protected:Npe \__pdf_backend:n #1
   { \__kernel_backend_literal:n { pdf: #1 } }
-\cs_generate_variant:Nn \__pdf_backend:n { x }
+\cs_generate_variant:Nn \__pdf_backend:n { e }
 \cs_new_protected:Npn \__pdf_backend_catalog_gput:nn #1#2
   { \__pdf_backend:n { put ~ @catalog << /#1 ~ #2 >> } }
 \cs_new_protected:Npn \__pdf_backend_info_gput:nn #1#2
@@ -624,15 +623,15 @@
     \use:c { __pdf_backend_object_write_ #2 :nn }
       { \__pdf_backend_object_ref:n {#1} } {#3}
   }
-\cs_generate_variant:Nn \__pdf_backend_object_write:nnn { nnx }
+\cs_generate_variant:Nn \__pdf_backend_object_write:nnn { nne }
 \cs_new_protected:Npn \__pdf_backend_object_write_array:nn #1#2
   {
-    \__pdf_backend:x
+    \__pdf_backend:e
       { obj ~ #1 ~ [ ~ \exp_not:n {#2} ~ ] }
   }
 \cs_new_protected:Npn \__pdf_backend_object_write_dict:nn #1#2
   {
-    \__pdf_backend:x
+    \__pdf_backend:e
       { obj ~ #1 ~ << ~ \exp_not:n {#2} ~ >> }
   }
 \cs_new_protected:Npn \__pdf_backend_object_write_fstream:nn #1#2
@@ -641,7 +640,7 @@
   { \__pdf_backend_object_write_stream:nnnn { } {#1} #2 }
 \cs_new_protected:Npn \__pdf_backend_object_write_stream:nnnn #1#2#3#4
   {
-    \__pdf_backend:x
+    \__pdf_backend:e
       {
         #1 stream ~ #2 ~
           ( \exp_not:n {#4} ) ~ << \exp_not:n {#3} >>
@@ -650,11 +649,11 @@
 \cs_new_protected:Npn \__pdf_backend_object_now:nn #1#2
   {
     \int_gincr:N \g__pdf_backend_object_int
-    \exp_args:Nnx \use:c { __pdf_backend_object_write_ #1 :nn }
+    \exp_args:Nne \use:c { __pdf_backend_object_write_ #1 :nn }
       { @pdf.obj \int_use:N \g__pdf_backend_object_int }
       {#2}
   }
-\cs_generate_variant:Nn \__pdf_backend_object_now:nn { nx }
+\cs_generate_variant:Nn \__pdf_backend_object_now:nn { ne }
 \cs_new:Npn \__pdf_backend_object_last:
  { @pdf.obj \int_use:N \g__pdf_backend_object_int }
 \cs_new:Npn \__pdf_backend_pageobject_ref:n #1
@@ -664,7 +663,7 @@
   {
     \int_gincr:N \g__pdf_backend_object_int
     \int_gset_eq:NN \g__pdf_backend_annotation_int \g__pdf_backend_object_int
-    \__pdf_backend:x
+    \__pdf_backend:e
       {
         ann ~ @pdf.obj \int_use:N \g__pdf_backend_object_int \c_space_tl
         width  ~ \dim_eval:n {#1} ~
@@ -680,10 +679,10 @@
   { \__pdf_backend_link_begin:n { #1 /Subtype /Link /A << /S /GoTo /D ( #2 ) >> } }
 \cs_new_protected:Npn \__pdf_backend_link_begin_user:nnw #1#2
   { \__pdf_backend_link_begin:n {#1#2} }
-\cs_new_protected:Npx \__pdf_backend_link_begin:n #1
+\cs_new_protected:Npe \__pdf_backend_link_begin:n #1
   {
     \exp_not:N \int_gincr:N \exp_not:N  \g__pdf_backend_link_int
-    \__pdf_backend:x
+    \__pdf_backend:e
       {
          bann ~
          @pdf.lnk
@@ -700,10 +699,10 @@
 \cs_new:Npn \__pdf_backend_link_last:
   { @pdf.lnk \int_use:N \g__pdf_backend_link_int }
 \cs_new_protected:Npn \__pdf_backend_link_margin:n #1
-  { \__kernel_backend_literal:x { dvipdfmx:config~g~ \dim_eval:n {#1} } }
+  { \__kernel_backend_literal:e { dvipdfmx:config~g~ \dim_eval:n {#1} } }
 \cs_new_protected:Npn \__pdf_backend_destination:nn #1#2
   {
-    \__pdf_backend:x
+    \__pdf_backend:e
       {
         dest ~ ( \exp_not:n {#1} )
         [
@@ -762,7 +761,7 @@
     \__kernel_kern:n { -#1 }
   }
 \cs_new_protected:Npn \__pdf_backend_compresslevel:n #1
-  { \__kernel_backend_literal:x { dvipdfmx:config~z~ \int_eval:n {#1} } }
+  { \__kernel_backend_literal:e { dvipdfmx:config~z~ \int_eval:n {#1} } }
 \cs_new_protected:Npn \__pdf_backend_compress_objects:n #1
   {
     \bool_if:nF {#1}
@@ -770,13 +769,13 @@
   }
 \cs_new_protected:Npn \__pdf_backend_version_major_gset:n #1
   {
-    \cs_gset:Npx \__pdf_backend_version_major: { \int_eval:n {#1} }
-    \__kernel_backend_literal:x { pdf:majorversion~ \__pdf_backend_version_major: }
+    \cs_gset:Npe \__pdf_backend_version_major: { \int_eval:n {#1} }
+    \__kernel_backend_literal:e { pdf:majorversion~ \__pdf_backend_version_major: }
   }
 \cs_new_protected:Npn \__pdf_backend_version_minor_gset:n #1
   {
-    \cs_gset:Npx \__pdf_backend_version_minor: { \int_eval:n {#1} }
-    \__kernel_backend_literal:x { pdf:minorversion~ \__pdf_backend_version_minor: }
+    \cs_gset:Npe \__pdf_backend_version_minor: { \int_eval:n {#1} }
+    \__kernel_backend_literal:e { pdf:minorversion~ \__pdf_backend_version_minor: }
   }
 \cs_new:Npn \__pdf_backend_version_major: { 1 }
 \cs_new:Npn \__pdf_backend_version_minor: { 5 }
@@ -808,7 +807,7 @@
 \tl_new:N \l__opacity_backend_stroke_tl
 \cs_new_protected:Npn \__opacity_backend_select:n #1
  {
-   \exp_args:Nx \__opacity_backend_select_aux:n
+   \exp_args:Ne \__opacity_backend_select_aux:n
      { \fp_eval:n { min(max(0,#1),1) } }
  }
 \cs_new_protected:Npn \__opacity_backend_select_aux:n #1
@@ -835,13 +834,13 @@
  }
 \cs_new_protected:Npn \__opacity_backend_fill:n #1
   {
-    \__opacity_backend_fill_stroke:xx
+    \__opacity_backend_fill_stroke:ee
       { \fp_eval:n { min(max(0,#1),1) } }
       \l__opacity_backend_stroke_tl
   }
 \cs_new_protected:Npn \__opacity_backend_stroke:n #1
   {
-    \__opacity_backend_fill_stroke:xx
+    \__opacity_backend_fill_stroke:ee
       \l__opacity_backend_fill_tl
       { \fp_eval:n { min(max(0,#1),1) } }
   }
@@ -863,7 +862,7 @@
         \group_insert_after:N \__opacity_backend_reset:
       }
   }
-\cs_generate_variant:Nn \__opacity_backend_fill_stroke:nn { xx }
+\cs_generate_variant:Nn \__opacity_backend_fill_stroke:nn { ee }
 %% 
 %%
 %% End of file `l3backend-dvipdfmx.def'.
diff --git a/Master/texmf-dist/tex/latex/l3backend/l3backend-dvips.def b/Master/texmf-dist/tex/latex/l3backend/l3backend-dvips.def
index 62287189df8..ede18214153 100644
--- a/Master/texmf-dist/tex/latex/l3backend/l3backend-dvips.def
+++ b/Master/texmf-dist/tex/latex/l3backend/l3backend-dvips.def
@@ -26,7 +26,7 @@
 %% 
 %% File: l3backend-basics.dtx
 \ProvidesExplFile
-  {l3backend-dvips.def}{2023-04-19}{}
+  {l3backend-dvips.def}{2023-10-10}{}
   {L3 backend support: dvips}
 \cs_if_exist:NTF \__kernel_dependency_version_check:nn
   {
@@ -45,7 +45,6 @@
 \cs_new_eq:NN \__kernel_backend_literal:e \tex_special:D
 \cs_new_protected:Npn \__kernel_backend_literal:n #1
   { \__kernel_backend_literal:e { \exp_not:n {#1} } }
-\cs_generate_variant:Nn \__kernel_backend_literal:n { x }
 \cs_if_exist:NTF \@ifl@t@r
   {
     \@ifl@t@r \fmtversion { 2020-10-01 }
@@ -58,10 +57,10 @@
   { \cs_new_eq:NN \__kernel_backend_first_shipout:n \use:n }
 \cs_new_protected:Npn \__kernel_backend_literal_postscript:n #1
   { \__kernel_backend_literal:n { ps:: #1 } }
-\cs_generate_variant:Nn \__kernel_backend_literal_postscript:n { x }
+\cs_generate_variant:Nn \__kernel_backend_literal_postscript:n { e }
 \cs_new_protected:Npn \__kernel_backend_postscript:n #1
   { \__kernel_backend_literal:n { ps: SDict ~ begin ~ #1 ~ end } }
-\cs_generate_variant:Nn \__kernel_backend_postscript:n { x }
+\cs_generate_variant:Nn \__kernel_backend_postscript:n { e }
 \bool_if:NT \g__kernel_backend_header_bool
   {
     \__kernel_backend_first_shipout:n
@@ -99,7 +98,7 @@
 \cs_new_protected:Npn \__color_backend_reset:
   { \__kernel_backend_literal:n { color~pop } }
 \prop_new:N \g__color_backend_colorant_prop
-\cs_new:Npx \__color_backend_devicen_colorants:n #1
+\cs_new:Npe \__color_backend_devicen_colorants:n #1
   {
     \exp_not:N \tl_if_blank:nF {#1}
       {
@@ -128,17 +127,17 @@
   { \__color_backend_select:n { separation ~ #1 ~ #2 } }
 \cs_new_eq:NN \__color_backend_select_devicen:nn \__color_backend_select_separation:nn
 \cs_new_protected:Npn \__color_backend_select_iccbased:nn #1#2 { }
-\cs_new_protected:Npx \__color_backend_separation_init:nnnnn #1#2#3#4#5
+\cs_new_protected:Npe \__color_backend_separation_init:nnnnn #1#2#3#4#5
   {
     \bool_if:NT \g__kernel_backend_header_bool
       {
-        \exp_args:Nx \__kernel_backend_first_shipout:n
+        \exp_not:N \exp_args:Ne \__kernel_backend_first_shipout:n
           {
             \exp_not:N \__color_backend_separation_init_aux:nnnnnn
               { \exp_not:N \int_use:N \g__color_model_int }
               {#1} {#2} {#3} {#4} {#5}
           }
-        \prop_gput:Nxx \exp_not:N \g__color_backend_colorant_prop
+        \prop_gput:Nee \exp_not:N \g__color_backend_colorant_prop
           { / \exp_not:N \str_convert_pdfname:n {#1} }
           {
             << ~
@@ -149,7 +148,7 @@
           }
       }
   }
-\cs_generate_variant:Nn \__color_backend_separation_init:nnnnn { nxx }
+\cs_generate_variant:Nn \__color_backend_separation_init:nnnnn { nee }
 \cs_new_protected:Npn \__color_backend_separation_init_aux:nnnnnn #1#2#3#4#5#6
   {
     \__kernel_backend_literal:e
@@ -242,7 +241,7 @@
   }
 \cs_new_protected:Npn \__color_backend_separation_init_CIELAB:nnn #1#2#3
   {
-    \__color_backend_separation_init:nxxnn
+    \__color_backend_separation_init:neenn
       {#2}
       {
         /CIEBasedABC ~
@@ -339,7 +338,7 @@
     \__kernel_backend_literal_postscript:n
       { Resolution~72~div~VResolution~72~div~scale }
     \__kernel_backend_literal_postscript:n { DVImag~dup~scale }
-    \__kernel_backend_literal_postscript:x
+    \__kernel_backend_literal_postscript:e
       {
         0 ~
         \dim_to_decimal_in_bp:n { \box_dp:N #1 } ~
@@ -359,7 +358,7 @@
   {
     \__kernel_backend_scope_begin:
     \__kernel_backend_align_begin:
-    \__kernel_backend_literal_postscript:x
+    \__kernel_backend_literal_postscript:e
       {
         \fp_compare:nNnTF {#2} = \c_zero_fp
           { 0 }
@@ -374,7 +373,7 @@
   {
     \__kernel_backend_scope_begin:
     \__kernel_backend_align_begin:
-    \__kernel_backend_literal_postscript:x
+    \__kernel_backend_literal_postscript:e
       {
         \fp_eval:n { round ( #2 , 5 ) } ~
         \fp_eval:n { round ( #3 , 5 ) } ~
@@ -386,7 +385,7 @@
   }
 %% File: l3backend-draw.dtx
 \cs_new_eq:NN \__draw_backend_literal:n \__kernel_backend_literal_postscript:n
-\cs_generate_variant:Nn \__draw_backend_literal:n { x }
+\cs_generate_variant:Nn \__draw_backend_literal:n { e }
 \cs_new_protected:Npn \__draw_backend_begin:
   {
     \__kernel_backend_literal:n { ps::[begin] }
@@ -403,7 +402,7 @@
   { \__draw_backend_literal:n { restore } }
 \cs_new_protected:Npn \__draw_backend_moveto:nn #1#2
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       {
         \dim_to_decimal_in_bp:n {#1} ~
         \dim_to_decimal_in_bp:n {#2} ~ moveto
@@ -411,7 +410,7 @@
   }
 \cs_new_protected:Npn \__draw_backend_lineto:nn #1#2
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       {
         \dim_to_decimal_in_bp:n {#1} ~
         \dim_to_decimal_in_bp:n {#2} ~ lineto
@@ -419,7 +418,7 @@
   }
 \cs_new_protected:Npn \__draw_backend_rectangle:nnnn #1#2#3#4
   {
-     \__draw_backend_literal:x
+     \__draw_backend_literal:e
        {
          \dim_to_decimal_in_bp:n {#4} ~ \dim_to_decimal_in_bp:n {#3} ~
          \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~
@@ -428,7 +427,7 @@
   }
 \cs_new_protected:Npn \__draw_backend_curveto:nnnnnn #1#2#3#4#5#6
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       {
         \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~
         \dim_to_decimal_in_bp:n {#3} ~ \dim_to_decimal_in_bp:n {#4} ~
@@ -451,7 +450,7 @@
     \__draw_backend_literal:n { grestore }
     \bool_if:NT \g__draw_draw_clip_bool
       {
-        \__draw_backend_literal:x
+        \__draw_backend_literal:e
           {
             \bool_if:NT \g__draw_draw_eor_bool { eo }
             clip
@@ -467,14 +466,14 @@
   }
 \cs_new_protected:Npn \__draw_backend_fill:
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       {
         \bool_if:NT \g__draw_draw_eor_bool { eo }
         fill
       }
     \bool_if:NT \g__draw_draw_clip_bool
       {
-        \__draw_backend_literal:x
+        \__draw_backend_literal:e
           {
             \bool_if:NT \g__draw_draw_eor_bool { eo }
             clip
@@ -485,7 +484,7 @@
   }
 \cs_new_protected:Npn \__draw_backend_fillstroke:
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       {
         \bool_if:NT \g__draw_draw_eor_bool { eo }
         fill
@@ -496,7 +495,7 @@
     \__draw_backend_literal:n { grestore }
     \bool_if:NT \g__draw_draw_clip_bool
       {
-        \__draw_backend_literal:x
+        \__draw_backend_literal:e
           {
             \bool_if:NT \g__draw_draw_eor_bool { eo }
             clip
@@ -512,7 +511,7 @@
   {
     \bool_if:NT \g__draw_draw_clip_bool
       {
-        \__draw_backend_literal:x
+        \__draw_backend_literal:e
           {
             \bool_if:NT \g__draw_draw_eor_bool { eo }
             clip
@@ -523,7 +522,7 @@
   }
 \cs_new_protected:Npn \__draw_backend_dash_pattern:nn #1#2
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       {
         [
           \exp_args:Nf \use:n
@@ -536,7 +535,7 @@
   { ~ \dim_to_decimal_in_bp:n {#1} }
 \cs_new_protected:Npn \__draw_backend_linewidth:n #1
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { \dim_to_decimal_in_bp:n {#1} ~ setlinewidth }
   }
 \cs_new_protected:Npn \__draw_backend_miterlimit:n #1
@@ -599,7 +598,7 @@
   }
 \cs_new_protected:Npn \__graphics_backend_include_eps:n #1
   {
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       {
         PSfile = #1 \c_space_tl
         llx = \dim_to_decimal_in_bp:n \l__graphics_llx_dim \c_space_tl
@@ -615,7 +614,7 @@
 \box_new:N \l__pdf_internal_box
 \cs_new_protected:Npn \__pdf_backend_pdfmark:n #1
   { \__kernel_backend_postscript:n { mark #1 ~ pdfmark } }
-\cs_generate_variant:Nn \__pdf_backend_pdfmark:n { x }
+\cs_generate_variant:Nn \__pdf_backend_pdfmark:n { e }
 \cs_new_protected:Npn \__pdf_backend_catalog_gput:nn #1#2
   { \__pdf_backend_pdfmark:n { { Catalog } << /#1 ~ #2 >> /PUT } }
 \cs_new_protected:Npn \__pdf_backend_info_gput:nn #1#2
@@ -636,10 +635,10 @@
       { \__pdf_backend_object_ref:n {#1} }
       {#2} {#3}
   }
-\cs_generate_variant:Nn \__pdf_backend_object_write:nnn { nnx }
+\cs_generate_variant:Nn \__pdf_backend_object_write:nnn { nne }
 \cs_new_protected:Npn \__pdf_backend_object_write_aux:nnn #1#2#3
   {
-    \__pdf_backend_pdfmark:x
+    \__pdf_backend_pdfmark:e
       {
         /_objdef ~ #1
         /type
@@ -656,17 +655,17 @@
   }
 \cs_new_protected:Npn \__pdf_backend_object_write_array:nn #1#2
   {
-    \__pdf_backend_pdfmark:x
+    \__pdf_backend_pdfmark:e
       { #1 ~0~ [ ~ \exp_not:n {#2} ~ ] ~ /PUTINTERVAL }
   }
 \cs_new_protected:Npn \__pdf_backend_object_write_dict:nn #1#2
   {
-    \__pdf_backend_pdfmark:x
+    \__pdf_backend_pdfmark:e
       { #1 << \exp_not:n {#2} >> /PUT }
   }
 \cs_new_protected:Npn \__pdf_backend_object_write_fstream:nn #1#2
   {
-    \exp_args:Nx
+    \exp_args:Ne
       \__pdf_backend_object_write_fstream:nnn {#1} #2
   }
 \cs_new_protected:Npn \__pdf_backend_object_write_fstream:nnn #1#2#3
@@ -681,7 +680,7 @@
   }
 \cs_new_protected:Npn \__pdf_backend_object_write_stream:nn #1#2
   {
-    \exp_args:Nx
+    \exp_args:Ne
       \__pdf_backend_object_write_stream:nnn {#1} #2
   }
 \cs_new_protected:Npn \__pdf_backend_object_write_stream:nnn #1#2#3
@@ -699,7 +698,7 @@
       { { pdf.obj \int_use:N \g__pdf_backend_object_int } }
       {#1} {#2}
   }
-\cs_generate_variant:Nn \__pdf_backend_object_now:nn { nx }
+\cs_generate_variant:Nn \__pdf_backend_object_now:nn { ne }
 \cs_new:Npn \__pdf_backend_object_last:
   { { pdf.obj \int_use:N \g__pdf_backend_object_int } }
 \cs_new:Npn \__pdf_backend_pageobject_ref:n #1
@@ -727,7 +726,7 @@
       }
     \int_gincr:N \g__pdf_backend_object_int
     \int_gset_eq:NN \g__pdf_backend_annotation_int \g__pdf_backend_object_int
-    \__pdf_backend_pdfmark:x
+    \__pdf_backend_pdfmark:e
       {
         /_objdef { pdf.obj \int_use:N \g__pdf_backend_object_int }
         pdf.rect
@@ -786,7 +785,7 @@
     \hbox_set_end:
     \__pdf_backend_link_minima:
     \hbox_set:Nn \l__pdf_backend_model_box { Gg }
-    \exp_args:Nx \__pdf_backend_link_outerbox:n
+    \exp_args:Ne \__pdf_backend_link_outerbox:n
       {
          \int_if_odd:nTF { \value { page } }
            { \oddsidemargin }
@@ -804,7 +803,7 @@
       }
     \int_gincr:N \g__pdf_backend_object_int
     \int_gset_eq:NN \g__pdf_backend_link_int \g__pdf_backend_object_int
-    \__kernel_backend_postscript:x
+    \__kernel_backend_postscript:e
       {
         mark
         /_objdef { pdf.obj \int_use:N \g__pdf_backend_link_int }
@@ -818,7 +817,7 @@
 \cs_new_protected:Npn \__pdf_backend_link_minima:
   {
     \hbox_set:Nn \l__pdf_backend_model_box { Gg }
-    \__kernel_backend_postscript:x
+    \__kernel_backend_postscript:e
       {
         /pdf.linkdp.pad ~
           \dim_to_decimal:n
@@ -846,7 +845,7 @@
   }
 \cs_new_protected:Npn \__pdf_backend_link_outerbox:n #1
   {
-    \__kernel_backend_postscript:x
+    \__kernel_backend_postscript:e
       {
         /pdf.outerbox
           [
@@ -886,9 +885,9 @@
       {
         \tl_put_right:Nn \@makecol@hook
           {
-            \box_if_empty:NF \@cclv
+            \box_if_empty:NF \l_shipout_box
               {
-                \vbox_set:Nn \@cclv
+                \vbox_set:Nn \l_shipout_box
                   {
                     \__kernel_backend_postscript:n
                       {
@@ -896,7 +895,7 @@
                           { pdf.bordertracking.continue }
                         if
                       }
-                    \vbox_unpack_drop:N \@cclv
+                    \vbox_unpack_drop:N \l_shipout_box
                     \__kernel_backend_postscript:n
                       { pdf.bordertracking.endpage }
                   }
@@ -911,7 +910,7 @@
   { { pdf.obj \int_use:N \g__pdf_backend_link_int } }
 \cs_new_protected:Npn \__pdf_backend_link_margin:n #1
   {
-    \__kernel_backend_postscript:x
+    \__kernel_backend_postscript:e
       {
         /pdf.linkmargin { \dim_to_decimal:n {#1} ~ pdf.pt.dvi } def
       }
@@ -919,7 +918,7 @@
 \cs_new_protected:Npn \__pdf_backend_destination:nn #1#2
   {
     \__kernel_backend_postscript:n { pdf.dest.anchor }
-    \__pdf_backend_pdfmark:x
+    \__pdf_backend_pdfmark:e
       {
         /View
         [
@@ -1001,11 +1000,11 @@
   }
 \cs_new_protected:Npn \__pdf_backend_version_major_gset:n #1
   {
-    \cs_gset:Npx \__pdf_backend_version_major: { \int_eval:n {#1} }
+    \cs_gset:Npe \__pdf_backend_version_major: { \int_eval:n {#1} }
   }
 \cs_new_protected:Npn \__pdf_backend_version_minor_gset:n #1
   {
-    \cs_gset:Npx \__pdf_backend_version_minor: { \int_eval:n {#1} }
+    \cs_gset:Npe \__pdf_backend_version_minor: { \int_eval:n {#1} }
   }
 \cs_new:Npn \__pdf_backend_version_major: { -1 }
 \cs_new:Npn \__pdf_backend_version_minor: { -1 }
@@ -1026,7 +1025,7 @@
 %% File: l3backend-opacity.dtx
 \cs_new_protected:Npn \__opacity_backend_select:n #1
   {
-    \exp_args:Nx \__opacity_backend_select_aux:n
+    \exp_args:Ne \__opacity_backend_select_aux:n
       { \fp_eval:n { min(max(0,#1),1) } }
   }
 \cs_new_protected:Npn \__opacity_backend_select_aux:n #1
@@ -1036,14 +1035,14 @@
   }
 \cs_new_protected:Npn \__opacity_backend_fill:n #1
   {
-    \__opacity_backend:xnn
+    \__opacity_backend:enn
       { \fp_eval:n { min(max(0,#1),1) } }
       { fill }
       { ca }
   }
 \cs_new_protected:Npn \__opacity_backend_stroke:n #1
   {
-    \__opacity_backend:xnn
+    \__opacity_backend:enn
       { \fp_eval:n { min(max(0,#1),1) } }
       { stroke }
       { CA }
@@ -1067,7 +1066,7 @@
         ifelse
       }
   }
-\cs_generate_variant:Nn \__opacity_backend:nnn { x }
+\cs_generate_variant:Nn \__opacity_backend:nnn { e }
 %% 
 %%
 %% End of file `l3backend-dvips.def'.
diff --git a/Master/texmf-dist/tex/latex/l3backend/l3backend-dvisvgm.def b/Master/texmf-dist/tex/latex/l3backend/l3backend-dvisvgm.def
index def201f4e9d..3f087c52655 100644
--- a/Master/texmf-dist/tex/latex/l3backend/l3backend-dvisvgm.def
+++ b/Master/texmf-dist/tex/latex/l3backend/l3backend-dvisvgm.def
@@ -26,7 +26,7 @@
 %% 
 %% File: l3backend-basics.dtx
 \ProvidesExplFile
-  {l3backend-dvisvgm.def}{2023-04-19}{}
+  {l3backend-dvisvgm.def}{2023-10-10}{}
   {L3 backend support: dvisvgm}
 \cs_if_exist:NTF \__kernel_dependency_version_check:nn
   {
@@ -45,7 +45,6 @@
 \cs_new_eq:NN \__kernel_backend_literal:e \tex_special:D
 \cs_new_protected:Npn \__kernel_backend_literal:n #1
   { \__kernel_backend_literal:e { \exp_not:n {#1} } }
-\cs_generate_variant:Nn \__kernel_backend_literal:n { x }
 \cs_if_exist:NTF \@ifl@t@r
   {
     \@ifl@t@r \fmtversion { 2020-10-01 }
@@ -58,7 +57,7 @@
   { \cs_new_eq:NN \__kernel_backend_first_shipout:n \use:n }
 \cs_new_protected:Npn \__kernel_backend_literal_svg:n #1
   { \__kernel_backend_literal:n { dvisvgm:raw~ #1 { ?nl } } }
-\cs_generate_variant:Nn \__kernel_backend_literal_svg:n { x }
+\cs_generate_variant:Nn \__kernel_backend_literal_svg:n { e }
 \int_new:N \g__kernel_backend_scope_int
 \int_new:N \l__kernel_backend_scope_int
 \cs_new_protected:Npn \__kernel_backend_scope_begin:
@@ -89,13 +88,13 @@
     \group_begin:
       \int_gset:Nn \g__kernel_backend_scope_int { 1 }
   }
-\cs_generate_variant:Nn \__kernel_backend_scope_begin:n { x }
+\cs_generate_variant:Nn \__kernel_backend_scope_begin:n { e }
 \cs_new_protected:Npn \__kernel_backend_scope:n #1
   {
     \__kernel_backend_literal_svg:n { <g ~ #1 > }
     \int_gincr:N \g__kernel_backend_scope_int
   }
-\cs_generate_variant:Nn \__kernel_backend_scope:n { x }
+\cs_generate_variant:Nn \__kernel_backend_scope:n { e }
 %% File: l3backend-color.dtx
 \cs_new_protected:Npn \__color_backend_select_cmyk:n #1
   { \__color_backend_select:n { cmyk ~ #1 } }
@@ -117,7 +116,7 @@
 \cs_new_protected:Npn \__color_backend_separation_init_CIELAB:nnnnnn #1#2#3 { }
 \cs_new_protected:Npn \__color_backend_select_iccbased:nn #1#2
   {
-    \__kernel_backend_literal_svg:x
+    \__kernel_backend_literal_svg:e
       {
         <style>
           @color-profile ~
@@ -146,7 +145,7 @@
 \cs_new_protected:Npn \__color_backend_stroke_cmyk:w
   #1 ~ #2 ~ #3 ~ #4 \s__color_stop
   {
-    \use:x
+    \use:e
       {
         \__color_backend:nnn
           { \fp_eval:n { -100 * ( 1 - min ( 1 , #1 + #4 ) ) } }
@@ -156,7 +155,7 @@
   }
 \cs_new_protected:Npn \__color_backend_stroke_gray:n #1
   {
-    \use:x
+    \use:e
       {
         \__color_backend_stroke_gray_aux:n
           { \fp_eval:n { 100 * (#1) } }
@@ -169,7 +168,7 @@
 \cs_new_protected:Npn \__color_backend_stroke_rgb:w
   #1 ~ #2 ~ #3 \s__color_stop
   {
-    \use:x
+    \use:e
       {
         \__color_backend:nnn
           { \fp_eval:n { 100 * (#1) } }
@@ -177,7 +176,7 @@
           { \fp_eval:n { 100 * (#3) } }
       }
   }
-\cs_new_protected:Npx \__color_backend:nnn #1#2#3
+\cs_new_protected:Npe \__color_backend:nnn #1#2#3
   {
     \__kernel_backend_scope:n
       {
@@ -204,9 +203,9 @@
 \cs_new_protected:Npn \__box_backend_clip:N #1
   {
     \int_gincr:N \g__kernel_clip_path_int
-    \__kernel_backend_literal_svg:x
+    \__kernel_backend_literal_svg:e
       { < clipPath~id = " l3cp \int_use:N \g__kernel_clip_path_int " > }
-    \__kernel_backend_literal_svg:x
+    \__kernel_backend_literal_svg:e
       {
         <
           path ~ d =
@@ -233,7 +232,7 @@
             scale ( 1 , -1 )
           "
       }
-    \__kernel_backend_scope:x
+    \__kernel_backend_scope:e
       {
         clip-path =
           "url ( \c_hash_str l3cp \int_use:N \g__kernel_clip_path_int ) "
@@ -253,7 +252,7 @@
 \int_new:N \g__kernel_clip_path_int
 \cs_new_protected:Npn \__box_backend_rotate:Nn #1#2
   {
-    \__kernel_backend_scope_begin:x
+    \__kernel_backend_scope_begin:e
       {
         transform =
           "
@@ -266,7 +265,7 @@
   }
 \cs_new_protected:Npn \__box_backend_scale:Nnn #1#2#3
   {
-    \__kernel_backend_scope_begin:x
+    \__kernel_backend_scope_begin:e
       {
         transform =
           "
@@ -285,7 +284,7 @@
   }
 %% File: l3backend-draw.dtx
 \cs_new_eq:NN \__draw_backend_literal:n \__kernel_backend_literal_svg:n
-\cs_generate_variant:Nn \__draw_backend_literal:n { x }
+\cs_generate_variant:Nn \__draw_backend_literal:n { e }
 \cs_new_eq:NN \__draw_backend_scope_begin: \__kernel_backend_scope_begin:
 \cs_new_eq:NN \__draw_backend_scope_end: \__kernel_backend_scope_end:
 \cs_new_protected:Npn \__draw_backend_begin:
@@ -327,7 +326,7 @@
   }
 \cs_new_protected:Npn \__draw_backend_add_to_path:n #1
   {
-    \tl_gset:Nx \g__draw_backend_path_tl
+    \tl_gset:Ne \g__draw_backend_path_tl
       {
         \g__draw_backend_path_tl
         \tl_if_empty:NF \g__draw_backend_path_tl { \c_space_tl }
@@ -346,7 +345,7 @@
     \bool_if:NTF \g__draw_draw_clip_bool
       {
         \int_gincr:N \g__kernel_clip_path_int
-        \__draw_backend_literal:x
+        \__draw_backend_literal:e
           {
             < clipPath~id = " l3cp \int_use:N \g__kernel_clip_path_int " >
               { ?nl }
@@ -358,14 +357,14 @@
                 #1
             />
           }
-        \__kernel_backend_scope:x
+        \__kernel_backend_scope:e
           {
             clip-path =
               "url( \c_hash_str l3cp \int_use:N \g__kernel_clip_path_int)"
           }
       }
       {
-        \__draw_backend_literal:x
+        \__draw_backend_literal:e
           { <path ~ d=" \g__draw_backend_path_tl " ~ #1 /> }
       }
     \tl_gclear:N \g__draw_backend_path_tl
@@ -391,14 +390,14 @@
     \bool_if:NT \g__draw_draw_clip_bool
       {
         \int_gincr:N \g__kernel_clip_path_int
-        \__draw_backend_literal:x
+        \__draw_backend_literal:e
           {
             < clipPath~id = " l3cp \int_use:N \g__kernel_clip_path_int " >
               { ?nl }
             <path~d=" \g__draw_backend_path_tl "/> { ?nl }
             < /clipPath >
           }
-        \__kernel_backend_scope:x
+        \__kernel_backend_scope:e
           {
             clip-path =
               "url( \c_hash_str l3cp \int_use:N \g__kernel_clip_path_int)"
@@ -409,7 +408,7 @@
   }
 \cs_new_protected:Npn \__draw_backend_dash_pattern:nn #1#2
   {
-    \use:x
+    \use:e
       {
         \__draw_backend_dash_aux:nn
           { \clist_map_function:nN {#1} \__draw_backend_dash:n }
@@ -420,7 +419,7 @@
   { , \dim_to_decimal_in_bp:n {#1} }
 \cs_new_protected:Npn \__draw_backend_dash_aux:nn #1#2
   {
-    \__kernel_backend_scope:x
+    \__kernel_backend_scope:e
       {
         stroke-dasharray =
           "
@@ -432,9 +431,9 @@
       }
   }
 \cs_new_protected:Npn \__draw_backend_linewidth:n #1
-  { \__kernel_backend_scope:x { stroke-width=" \dim_to_decimal:n {#1} " } }
+  { \__kernel_backend_scope:e { stroke-width=" \dim_to_decimal:n {#1} " } }
 \cs_new_protected:Npn \__draw_backend_miterlimit:n #1
-  { \__kernel_backend_scope:x { stroke-miterlimit=" #1 " } }
+  { \__kernel_backend_scope:e { stroke-miterlimit=" #1 " } }
 \cs_new_protected:Npn \__draw_backend_cap_butt:
   { \__kernel_backend_scope:n { stroke-linecap="butt" } }
 \cs_new_protected:Npn \__draw_backend_cap_round:
@@ -527,10 +526,10 @@
   }
 \cs_new_protected:Npn \__graphics_backend_getbb_svg_auxi:nNn #1#2#3
   {
-    \use:x
+    \use:e
       {
         \cs_set_protected:Npn \__graphics_backend_getbb_svg_auxii:w
-          ####1 \tl_to_str:n {#1} = ####2 \tl_to_str:n {#1} = ####3
+          ##1 \tl_to_str:n {#1} = ##2 \tl_to_str:n {#1} = ##3
           \s__graphics_stop
       }
       {
@@ -549,7 +548,7 @@
                 ##2 \s__graphics_stop
           }
       }
-    \use:x
+    \use:e
       {
         \__graphics_backend_getbb_svg_auxii:w #3
           \tl_to_str:n {#1} = \tl_to_str:n {#1} =
@@ -596,7 +595,7 @@
   { \__graphics_backend_include:nn { pdffile } {#1} }
 \cs_new_protected:Npn \__graphics_backend_include:nn #1#2
   {
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       {
         #1 = #2 \c_space_tl
         llx = \dim_to_decimal_in_bp:n \l__graphics_llx_dim \c_space_tl
@@ -611,7 +610,7 @@
       {
         \hbox:n
           {
-            \__kernel_backend_literal:x
+            \__kernel_backend_literal:e
               {
                 dvisvgm:img~
                 \dim_to_decimal:n { \l__graphics_urx_dim } ~
@@ -635,7 +634,7 @@
 \cs_new_protected:Npn \__pdf_backend_link_begin_user:nnw #1#2 { }
 \cs_new_protected:Npn \__pdf_backend_link_begin:nnnw #1#2#3 { }
 \cs_new_protected:Npn \__pdf_backend_link_end: { }
-\cs_new:Npx \__pdf_backend_link_last: { }
+\cs_new:Npe \__pdf_backend_link_last: { }
 \cs_new_protected:Npn \__pdf_backend_link_margin:n #1 { }
 \cs_new_protected:Npn \__pdf_backend_destination:nn #1#2 { }
 \cs_new_protected:Npn \__pdf_backend_destination:nnnn #1#2#3#4 { }
@@ -644,9 +643,9 @@
 \cs_new_protected:Npn \__pdf_backend_object_new:nn #1 { }
 \cs_new:Npn \__pdf_backend_object_ref:n #1 { }
 \cs_new_protected:Npn \__pdf_backend_object_write:nnn #1#2#3 { }
-\cs_new_protected:Npn \__pdf_backend_object_write:nnx #1#2#3 { }
+\cs_new_protected:Npn \__pdf_backend_object_write:nne #1#2#3 { }
 \cs_new_protected:Npn \__pdf_backend_object_now:nn #1#2 { }
-\cs_new_protected:Npn \__pdf_backend_object_now:nx #1#2 { }
+\cs_new_protected:Npn \__pdf_backend_object_now:ne #1#2 { }
 \cs_new:Npn \__pdf_backend_object_last: { }
 \cs_new:Npn \__pdf_backend_pageobject_ref:n #1 { }
 \cs_new_protected:Npn \__pdf_backend_compresslevel:n #1 { }
@@ -666,7 +665,7 @@
 \cs_new_protected:Npn \__opacity_backend_stroke:n #1
   { \__opacity_backend:nn { {#1} } { stroke- } }
 \cs_new_protected:Npn \__opacity_backend:nn #1#2
-  { \__kernel_backend_scope:x { #2 opacity = " \fp_eval:n { min(max(0,#1),1) } " } }
+  { \__kernel_backend_scope:e { #2 opacity = " \fp_eval:n { min(max(0,#1),1) } " } }
 %% 
 %%
 %% End of file `l3backend-dvisvgm.def'.
diff --git a/Master/texmf-dist/tex/latex/l3backend/l3backend-luatex.def b/Master/texmf-dist/tex/latex/l3backend/l3backend-luatex.def
index 040c5415daf..4207e02855e 100644
--- a/Master/texmf-dist/tex/latex/l3backend/l3backend-luatex.def
+++ b/Master/texmf-dist/tex/latex/l3backend/l3backend-luatex.def
@@ -26,7 +26,7 @@
 %% 
 %% File: l3backend-basics.dtx
 \ProvidesExplFile
-  {l3backend-luatex.def}{2023-04-19}{}
+  {l3backend-luatex.def}{2023-10-10}{}
   {L3 backend support: PDF output (LuaTeX)}
 \cs_if_exist:NTF \__kernel_dependency_version_check:nn
   {
@@ -45,7 +45,6 @@
 \cs_new_eq:NN \__kernel_backend_literal:e \tex_special:D
 \cs_new_protected:Npn \__kernel_backend_literal:n #1
   { \__kernel_backend_literal:e { \exp_not:n {#1} } }
-\cs_generate_variant:Nn \__kernel_backend_literal:n { x }
 \cs_if_exist:NTF \@ifl@t@r
   {
     \@ifl@t@r \fmtversion { 2020-10-01 }
@@ -61,12 +60,17 @@
     \tex_pdfextension:D literal
       { \exp_not:n {#1} }
   }
-\cs_generate_variant:Nn \__kernel_backend_literal_pdf:n { x }
+\cs_generate_variant:Nn \__kernel_backend_literal_pdf:n { e }
 \cs_new_protected:Npn \__kernel_backend_literal_page:n #1
   {
     \tex_pdfextension:D literal ~
         page { \exp_not:n {#1} }
   }
+\cs_new_protected:Npn \__kernel_backend_literal_page:e #1
+  {
+    \tex_pdfextension:D literal ~
+        page {#1}
+  }
 \cs_new_protected:Npn \__kernel_backend_scope_begin:
   {
     \tex_pdfextension:D save \scan_stop:
@@ -80,7 +84,7 @@
     \tex_pdfextension:D setmatrix
         { \exp_not:n {#1} }
   }
-\cs_generate_variant:Nn \__kernel_backend_matrix:n { x }
+\cs_generate_variant:Nn \__kernel_backend_matrix:n { e }
 %% File: l3backend-color.dtx
 \int_new:N \l__color_backend_stack_int
 \cs_new_protected:Npn \__kernel_color_backend_stack_init:Nnn #1#2#3
@@ -121,7 +125,7 @@
 \cs_new_protected:Npn \__color_backend_reset:
   { \__kernel_color_backend_stack_pop:n \l__color_backend_stack_int }
 \prop_new:N \g__color_backend_colorant_prop
-\cs_new:Npx \__color_backend_devicen_colorants:n #1
+\cs_new:Npe \__color_backend_devicen_colorants:n #1
   {
     \exp_not:N \tl_if_blank:nF {#1}
       {
@@ -156,7 +160,7 @@
       { \cs_if_exist_p:N \pdfmanagement_if_active_p: }
       { \pdfmanagement_if_active_p: }
       {
-        \use:x
+        \use:e
           {
             \pdfmanagement_add:nnn
               { Page / Resources / ColorSpace }
@@ -167,7 +171,7 @@
   }
 \cs_new_protected:Npn \__color_backend_separation_init:nnnnn #1#2#3#4#5
   {
-    \pdf_object_unnamed_write:nx { dict }
+    \pdf_object_unnamed_write:ne { dict }
       {
         /FunctionType ~ 2
         /Domain ~ [0 ~ 1]
@@ -175,19 +179,19 @@
         /C0 ~ [#4] ~
         /C1 ~ [#5] /N ~ 1
       }
-    \exp_args:Nx \__color_backend_separation_init:nn
+    \exp_args:Ne \__color_backend_separation_init:nn
       { \str_convert_pdfname:n {#1} } {#2}
     \__color_backend_init_resource:n { color \int_use:N \g__color_model_int }
   }
 \cs_new_protected:Npn \__color_backend_separation_init:nn #1#2
   {
-    \use:x
+    \use:e
       {
         \pdf_object_new:n { color \int_use:N \g__color_model_int }
         \pdf_object_write:nnn { color \int_use:N \g__color_model_int } { array }
           { /Separation /#1 ~ #2 ~ \pdf_object_ref_last: }
       }
-    \prop_gput:Nnx \g__color_backend_colorant_prop { /#1 }
+    \prop_gput:Nne \g__color_backend_colorant_prop { /#1 }
       { \pdf_object_ref_last: }
   }
 \cs_new_protected:Npn \__color_backend_separation_init_CIELAB:nnn #1#2#3
@@ -195,7 +199,7 @@
     \pdf_object_if_exist:nF { __color_illuminant_CIELAB_ #1 }
       {
         \pdf_object_new:n { __color_illuminant_CIELAB_ #1 }
-        \pdf_object_write:nnx { __color_illuminant_CIELAB_ #1 } { array }
+        \pdf_object_write:nne { __color_illuminant_CIELAB_ #1 } { array }
           {
             /Lab ~
             <<
@@ -214,7 +218,7 @@
   }
 \cs_new_protected:Npn \__color_backend_devicen_init:nnn #1#2#3
   {
-    \pdf_object_unnamed_write:nx { stream }
+    \pdf_object_unnamed_write:ne { stream }
       {
         {
           /FunctionType ~ 4 ~
@@ -236,7 +240,7 @@
         }
         { {#3} }
      }
-    \use:x
+    \use:e
       {
         \pdf_object_new:n { color \int_use:N \g__color_model_int }
         \pdf_object_write:nnn { color \int_use:N \g__color_model_int } { array }
@@ -261,7 +265,7 @@
     \pdf_object_if_exist:nF { __color_icc_ #1 }
       {
         \pdf_object_new:n { __color_icc_ #1 }
-        \pdf_object_write:nnx { __color_icc_ #1 } { fstream }
+        \pdf_object_write:nne { __color_icc_ #1 } { fstream }
           {
             {
               /N ~ \exp_not:n { #2 } ~
@@ -270,7 +274,7 @@
             {#1}
           }
       }
-    \pdf_object_unnamed_write:nx { array }
+    \pdf_object_unnamed_write:ne { array }
       { /ICCBased ~ \pdf_object_ref:n { __color_icc_ #1 } }
     \__color_backend_init_resource:n { color \int_use:N \g__color_model_int }
   }
@@ -285,7 +289,7 @@
             {#1}
           }
       }
-    \pdf_object_unnamed_write:nx { array }
+    \pdf_object_unnamed_write:ne { array }
       { /ICCBased ~ \pdf_object_ref:n { __color_icc_ #1 } }
     \__color_backend_init_resource:n { Default #2 }
   }
@@ -326,7 +330,7 @@
 \cs_new_protected:Npn \__box_backend_clip:N #1
   {
     \__kernel_backend_scope_begin:
-    \__kernel_backend_literal_pdf:x
+    \__kernel_backend_literal_pdf:e
       {
         0~
         \dim_to_decimal_in_bp:n { -\box_dp:N #1 } ~
@@ -348,7 +352,7 @@
     \fp_compare:nNnT \l__box_backend_cos_fp = \c_zero_fp
       { \fp_zero:N \l__box_backend_cos_fp }
     \fp_set:Nn \l__box_backend_sin_fp { round ( sind ( #2 ) , 5 ) }
-    \__kernel_backend_matrix:x
+    \__kernel_backend_matrix:e
       {
         \fp_use:N \l__box_backend_cos_fp \c_space_tl
         \fp_compare:nNnTF \l__box_backend_sin_fp = \c_zero_fp
@@ -369,7 +373,7 @@
 \cs_new_protected:Npn \__box_backend_scale:Nnn #1#2#3
   {
     \__kernel_backend_scope_begin:
-    \__kernel_backend_matrix:x
+    \__kernel_backend_matrix:e
       {
         \fp_eval:n { round ( #2 , 5 ) } ~
         0~0~
@@ -380,7 +384,7 @@
   }
 %% File: l3backend-draw.dtx
 \cs_new_eq:NN \__draw_backend_literal:n \__kernel_backend_literal_pdf:n
-\cs_generate_variant:Nn \__draw_backend_literal:n { x }
+\cs_generate_variant:Nn \__draw_backend_literal:n { e }
 \cs_new_protected:Npn \__draw_backend_begin:
   { \__draw_backend_scope_begin: }
 \cs_new_protected:Npn \__draw_backend_end:
@@ -389,17 +393,17 @@
 \cs_new_eq:NN \__draw_backend_scope_end: \__kernel_backend_scope_end:
 \cs_new_protected:Npn \__draw_backend_moveto:nn #1#2
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~ m }
   }
 \cs_new_protected:Npn \__draw_backend_lineto:nn #1#2
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~ l }
   }
 \cs_new_protected:Npn \__draw_backend_curveto:nnnnnn #1#2#3#4#5#6
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       {
         \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~
         \dim_to_decimal_in_bp:n {#3} ~ \dim_to_decimal_in_bp:n {#4} ~
@@ -409,7 +413,7 @@
  }
 \cs_new_protected:Npn \__draw_backend_rectangle:nnnn #1#2#3#4
   {
-     \__draw_backend_literal:x
+     \__draw_backend_literal:e
       {
         \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~
         \dim_to_decimal_in_bp:n {#3} ~ \dim_to_decimal_in_bp:n {#4} ~
@@ -429,24 +433,24 @@
   { \__draw_backend_literal:n { s } }
 \cs_new_protected:Npn \__draw_backend_fill:
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { f \bool_if:NT \g__draw_draw_eor_bool * }
   }
 \cs_new_protected:Npn \__draw_backend_fillstroke:
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { B \bool_if:NT \g__draw_draw_eor_bool * }
   }
 \cs_new_protected:Npn \__draw_backend_clip:
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { W \bool_if:NT \g__draw_draw_eor_bool * }
   }
 \cs_new_protected:Npn \__draw_backend_discardpath:
   { \__draw_backend_literal:n { n } }
 \cs_new_protected:Npn \__draw_backend_dash_pattern:nn #1#2
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       {
         [
           \exp_args:Nf \use:n
@@ -459,11 +463,11 @@
   { ~ \dim_to_decimal_in_bp:n {#1} }
 \cs_new_protected:Npn \__draw_backend_linewidth:n #1
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { \dim_to_decimal_in_bp:n {#1} ~ w }
   }
 \cs_new_protected:Npn \__draw_backend_miterlimit:n #1
-  { \__draw_backend_literal:x { #1 ~ M } }
+  { \__draw_backend_literal:e { #1 ~ M } }
 \cs_new_protected:Npn \__draw_backend_cap_butt:
   { \__draw_backend_literal:n { 0 ~ J } }
 \cs_new_protected:Npn \__draw_backend_cap_round:
@@ -510,7 +514,7 @@
   {
     \int_zero:N \l__graphics_page_int
     \tl_clear:N \l__graphics_pagebox_tl
-    \tl_set:Nx \l__graphics_attr_tl
+    \tl_set:Ne \l__graphics_attr_tl
       {
         \tl_if_empty:NF \l__graphics_decodearray_str
           { :D \l__graphics_decodearray_str }
@@ -527,7 +531,7 @@
   {
     \tl_clear:N \l__graphics_decodearray_str
     \bool_set_false:N \l__graphics_interpolate_bool
-    \tl_set:Nx \l__graphics_attr_tl
+    \tl_set:Ne \l__graphics_attr_tl
       {
         : \l__graphics_pagebox_tl
         \int_compare:nNnT \l__graphics_page_int > 1
@@ -539,7 +543,7 @@
   }
 \cs_new_protected:Npn \__graphics_backend_getbb_auxi:n #1
   {
-    \__graphics_bb_restore:xF { #1 \l__graphics_attr_tl }
+    \__graphics_bb_restore:eF { #1 \l__graphics_attr_tl }
       { \__graphics_backend_getbb_auxii:n {#1} }
   }
 \cs_new_protected:Npn \__graphics_backend_getbb_auxii:n #1
@@ -548,7 +552,7 @@
       { \__graphics_backend_dequote:w #1 " #1 " \s__graphics_stop }
     \int_const:cn { c__graphics_ #1 \l__graphics_attr_tl _int }
       { \tex_the:D \tex_pdflastximage:D }
-    \__graphics_bb_save:x { #1 \l__graphics_attr_tl }
+    \__graphics_bb_save:e { #1 \l__graphics_attr_tl }
   }
 \cs_new_protected:Npn \__graphics_backend_getbb_auxiii:n #1
   {
@@ -599,7 +603,7 @@
           \l__graphics_backend_dir_str
           \l__graphics_backend_name_str
           \l__graphics_backend_ext_str
-        \exp_args:Nx \__graphics_backend_getbb_eps:nn
+        \exp_args:Ne \__graphics_backend_getbb_eps:nn
           {
             \exp_args:Ne \__kernel_file_name_quote:n
               {
@@ -625,7 +629,7 @@
       {
         \file_parse_full_name:nNNN {#1}
           \l__graphics_backend_dir_str \l__graphics_backend_name_str \l__graphics_backend_ext_str
-        \exp_args:Nx \__graphics_backend_include_pdf:n
+        \exp_args:Ne \__graphics_backend_include_pdf:n
           {
             \exp_args:Ne \__kernel_file_name_quote:n
               {
@@ -653,7 +657,7 @@
       depth  ~ \dim_eval:n {#3} ~
       {#4}
   }
-\cs_new:Npx \__pdf_backend_annotation_last:
+\cs_new:Npe \__pdf_backend_annotation_last:
   {
     \exp_not:N \int_value:w
       \exp_not:N \tex_pdffeedback:D lastannot ~
@@ -673,7 +677,7 @@
   {
     \tex_pdfextension:D endlink \scan_stop:
   }
-\cs_new:Npx \__pdf_backend_link_last:
+\cs_new:Npe \__pdf_backend_link_last:
   {
     \exp_not:N \int_value:w
       \exp_not:N \tex_pdffeedback:D lastlink ~
@@ -758,7 +762,7 @@
             }
         }
   }
-\cs_generate_variant:Nn \__pdf_backend_object_write:nnn { nnx }
+\cs_generate_variant:Nn \__pdf_backend_object_write:nnn { nne }
 \cs_new:Npn \__pdf_exp_not_i:nn #1#2 { \exp_not:n {#1} }
 \cs_new:Npn \__pdf_exp_not_ii:nn #1#2 { \exp_not:n {#2} }
 \cs_new_protected:Npn \__pdf_backend_object_now:nn #1#2
@@ -766,14 +770,14 @@
     \tex_immediate:D \tex_pdfextension:D obj ~
       \__pdf_backend_object_write:nn {#1} {#2}
   }
-\cs_generate_variant:Nn \__pdf_backend_object_now:nn { nx }
-\cs_new:Npx \__pdf_backend_object_last:
+\cs_generate_variant:Nn \__pdf_backend_object_now:nn { ne }
+\cs_new:Npe \__pdf_backend_object_last:
   {
     \exp_not:N \int_value:w
       \exp_not:N \tex_pdffeedback:D lastobj ~
       \c_space_tl 0 ~ R
   }
-\cs_new:Npx \__pdf_backend_pageobject_ref:n #1
+\cs_new:Npe \__pdf_backend_pageobject_ref:n #1
   {
     \exp_not:N \int_value:w
       \exp_not:N \tex_pdffeedback:D pageref
@@ -797,7 +801,7 @@
       \tex_pdfvariable:D objcompresslevel
         #1 \scan_stop:
   }
-\cs_new_protected:Npx \__pdf_backend_version_major_gset:n #1
+\cs_new_protected:Npe \__pdf_backend_version_major_gset:n #1
   {
     \int_compare:nNnT \tex_luatexversion:D > { 106 }
       {
@@ -811,7 +815,7 @@
       \tex_pdfvariable:D minorversion
         \int_eval:n {#1} \scan_stop:
   }
-\cs_new:Npx \__pdf_backend_version_major:
+\cs_new:Npe \__pdf_backend_version_major:
   {
     \int_compare:nNnTF \tex_luatexversion:D > { 106 }
       { \exp_not:N \tex_the:D \tex_pdfvariable:D majorversion }
@@ -845,7 +849,7 @@
 \tl_new:N \l__opacity_backend_stroke_tl
 \cs_new_protected:Npn \__opacity_backend_select:n #1
  {
-   \exp_args:Nx \__opacity_backend_select_aux:n
+   \exp_args:Ne \__opacity_backend_select_aux:n
      { \fp_eval:n { min(max(0,#1),1) } }
  }
 \cs_new_protected:Npn \__opacity_backend_select_aux:n #1
@@ -871,13 +875,13 @@
  }
 \cs_new_protected:Npn \__opacity_backend_fill:n #1
   {
-    \__opacity_backend_fill_stroke:xx
+    \__opacity_backend_fill_stroke:ee
       { \fp_eval:n { min(max(0,#1),1) } }
       \l__opacity_backend_stroke_tl
   }
 \cs_new_protected:Npn \__opacity_backend_stroke:n #1
   {
-    \__opacity_backend_fill_stroke:xx
+    \__opacity_backend_fill_stroke:ee
       \l__opacity_backend_fill_tl
       { \fp_eval:n { min(max(0,#1),1) } }
   }
@@ -899,7 +903,7 @@
         \group_insert_after:N \__opacity_backend_reset:
       }
   }
-\cs_generate_variant:Nn \__opacity_backend_fill_stroke:nn { xx }
+\cs_generate_variant:Nn \__opacity_backend_fill_stroke:nn { ee }
 %% 
 %%
 %% End of file `l3backend-luatex.def'.
diff --git a/Master/texmf-dist/tex/latex/l3backend/l3backend-pdftex.def b/Master/texmf-dist/tex/latex/l3backend/l3backend-pdftex.def
index 1592155c3c0..d5c64bc74a4 100644
--- a/Master/texmf-dist/tex/latex/l3backend/l3backend-pdftex.def
+++ b/Master/texmf-dist/tex/latex/l3backend/l3backend-pdftex.def
@@ -26,7 +26,7 @@
 %% 
 %% File: l3backend-basics.dtx
 \ProvidesExplFile
-  {l3backend-pdftex.def}{2023-04-19}{}
+  {l3backend-pdftex.def}{2023-10-10}{}
   {L3 backend support: PDF output (pdfTeX)}
 \cs_if_exist:NTF \__kernel_dependency_version_check:nn
   {
@@ -45,7 +45,6 @@
 \cs_new_eq:NN \__kernel_backend_literal:e \tex_special:D
 \cs_new_protected:Npn \__kernel_backend_literal:n #1
   { \__kernel_backend_literal:e { \exp_not:n {#1} } }
-\cs_generate_variant:Nn \__kernel_backend_literal:n { x }
 \cs_if_exist:NTF \@ifl@t@r
   {
     \@ifl@t@r \fmtversion { 2020-10-01 }
@@ -61,12 +60,17 @@
     \tex_pdfliteral:D
       { \exp_not:n {#1} }
   }
-\cs_generate_variant:Nn \__kernel_backend_literal_pdf:n { x }
+\cs_generate_variant:Nn \__kernel_backend_literal_pdf:n { e }
 \cs_new_protected:Npn \__kernel_backend_literal_page:n #1
   {
     \tex_pdfliteral:D
         page { \exp_not:n {#1} }
   }
+\cs_new_protected:Npn \__kernel_backend_literal_page:e #1
+  {
+    \tex_pdfliteral:D
+        page {#1}
+  }
 \cs_new_protected:Npn \__kernel_backend_scope_begin:
   {
     \tex_pdfsave:D
@@ -80,7 +84,7 @@
     \tex_pdfsetmatrix:D
         { \exp_not:n {#1} }
   }
-\cs_generate_variant:Nn \__kernel_backend_matrix:n { x }
+\cs_generate_variant:Nn \__kernel_backend_matrix:n { e }
 %% File: l3backend-color.dtx
 \int_new:N \l__color_backend_stack_int
 \cs_new_protected:Npn \__kernel_color_backend_stack_init:Nnn #1#2#3
@@ -121,7 +125,7 @@
 \cs_new_protected:Npn \__color_backend_reset:
   { \__kernel_color_backend_stack_pop:n \l__color_backend_stack_int }
 \prop_new:N \g__color_backend_colorant_prop
-\cs_new:Npx \__color_backend_devicen_colorants:n #1
+\cs_new:Npe \__color_backend_devicen_colorants:n #1
   {
     \exp_not:N \tl_if_blank:nF {#1}
       {
@@ -156,7 +160,7 @@
       { \cs_if_exist_p:N \pdfmanagement_if_active_p: }
       { \pdfmanagement_if_active_p: }
       {
-        \use:x
+        \use:e
           {
             \pdfmanagement_add:nnn
               { Page / Resources / ColorSpace }
@@ -167,7 +171,7 @@
   }
 \cs_new_protected:Npn \__color_backend_separation_init:nnnnn #1#2#3#4#5
   {
-    \pdf_object_unnamed_write:nx { dict }
+    \pdf_object_unnamed_write:ne { dict }
       {
         /FunctionType ~ 2
         /Domain ~ [0 ~ 1]
@@ -175,19 +179,19 @@
         /C0 ~ [#4] ~
         /C1 ~ [#5] /N ~ 1
       }
-    \exp_args:Nx \__color_backend_separation_init:nn
+    \exp_args:Ne \__color_backend_separation_init:nn
       { \str_convert_pdfname:n {#1} } {#2}
     \__color_backend_init_resource:n { color \int_use:N \g__color_model_int }
   }
 \cs_new_protected:Npn \__color_backend_separation_init:nn #1#2
   {
-    \use:x
+    \use:e
       {
         \pdf_object_new:n { color \int_use:N \g__color_model_int }
         \pdf_object_write:nnn { color \int_use:N \g__color_model_int } { array }
           { /Separation /#1 ~ #2 ~ \pdf_object_ref_last: }
       }
-    \prop_gput:Nnx \g__color_backend_colorant_prop { /#1 }
+    \prop_gput:Nne \g__color_backend_colorant_prop { /#1 }
       { \pdf_object_ref_last: }
   }
 \cs_new_protected:Npn \__color_backend_separation_init_CIELAB:nnn #1#2#3
@@ -195,7 +199,7 @@
     \pdf_object_if_exist:nF { __color_illuminant_CIELAB_ #1 }
       {
         \pdf_object_new:n { __color_illuminant_CIELAB_ #1 }
-        \pdf_object_write:nnx { __color_illuminant_CIELAB_ #1 } { array }
+        \pdf_object_write:nne { __color_illuminant_CIELAB_ #1 } { array }
           {
             /Lab ~
             <<
@@ -214,7 +218,7 @@
   }
 \cs_new_protected:Npn \__color_backend_devicen_init:nnn #1#2#3
   {
-    \pdf_object_unnamed_write:nx { stream }
+    \pdf_object_unnamed_write:ne { stream }
       {
         {
           /FunctionType ~ 4 ~
@@ -236,7 +240,7 @@
         }
         { {#3} }
      }
-    \use:x
+    \use:e
       {
         \pdf_object_new:n { color \int_use:N \g__color_model_int }
         \pdf_object_write:nnn { color \int_use:N \g__color_model_int } { array }
@@ -261,7 +265,7 @@
     \pdf_object_if_exist:nF { __color_icc_ #1 }
       {
         \pdf_object_new:n { __color_icc_ #1 }
-        \pdf_object_write:nnx { __color_icc_ #1 } { fstream }
+        \pdf_object_write:nne { __color_icc_ #1 } { fstream }
           {
             {
               /N ~ \exp_not:n { #2 } ~
@@ -270,7 +274,7 @@
             {#1}
           }
       }
-    \pdf_object_unnamed_write:nx { array }
+    \pdf_object_unnamed_write:ne { array }
       { /ICCBased ~ \pdf_object_ref:n { __color_icc_ #1 } }
     \__color_backend_init_resource:n { color \int_use:N \g__color_model_int }
   }
@@ -285,7 +289,7 @@
             {#1}
           }
       }
-    \pdf_object_unnamed_write:nx { array }
+    \pdf_object_unnamed_write:ne { array }
       { /ICCBased ~ \pdf_object_ref:n { __color_icc_ #1 } }
     \__color_backend_init_resource:n { Default #2 }
   }
@@ -325,7 +329,7 @@
 \cs_new_protected:Npn \__box_backend_clip:N #1
   {
     \__kernel_backend_scope_begin:
-    \__kernel_backend_literal_pdf:x
+    \__kernel_backend_literal_pdf:e
       {
         0~
         \dim_to_decimal_in_bp:n { -\box_dp:N #1 } ~
@@ -347,7 +351,7 @@
     \fp_compare:nNnT \l__box_backend_cos_fp = \c_zero_fp
       { \fp_zero:N \l__box_backend_cos_fp }
     \fp_set:Nn \l__box_backend_sin_fp { round ( sind ( #2 ) , 5 ) }
-    \__kernel_backend_matrix:x
+    \__kernel_backend_matrix:e
       {
         \fp_use:N \l__box_backend_cos_fp \c_space_tl
         \fp_compare:nNnTF \l__box_backend_sin_fp = \c_zero_fp
@@ -368,7 +372,7 @@
 \cs_new_protected:Npn \__box_backend_scale:Nnn #1#2#3
   {
     \__kernel_backend_scope_begin:
-    \__kernel_backend_matrix:x
+    \__kernel_backend_matrix:e
       {
         \fp_eval:n { round ( #2 , 5 ) } ~
         0~0~
@@ -379,7 +383,7 @@
   }
 %% File: l3backend-draw.dtx
 \cs_new_eq:NN \__draw_backend_literal:n \__kernel_backend_literal_pdf:n
-\cs_generate_variant:Nn \__draw_backend_literal:n { x }
+\cs_generate_variant:Nn \__draw_backend_literal:n { e }
 \cs_new_protected:Npn \__draw_backend_begin:
   { \__draw_backend_scope_begin: }
 \cs_new_protected:Npn \__draw_backend_end:
@@ -388,17 +392,17 @@
 \cs_new_eq:NN \__draw_backend_scope_end: \__kernel_backend_scope_end:
 \cs_new_protected:Npn \__draw_backend_moveto:nn #1#2
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~ m }
   }
 \cs_new_protected:Npn \__draw_backend_lineto:nn #1#2
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~ l }
   }
 \cs_new_protected:Npn \__draw_backend_curveto:nnnnnn #1#2#3#4#5#6
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       {
         \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~
         \dim_to_decimal_in_bp:n {#3} ~ \dim_to_decimal_in_bp:n {#4} ~
@@ -408,7 +412,7 @@
  }
 \cs_new_protected:Npn \__draw_backend_rectangle:nnnn #1#2#3#4
   {
-     \__draw_backend_literal:x
+     \__draw_backend_literal:e
       {
         \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~
         \dim_to_decimal_in_bp:n {#3} ~ \dim_to_decimal_in_bp:n {#4} ~
@@ -428,24 +432,24 @@
   { \__draw_backend_literal:n { s } }
 \cs_new_protected:Npn \__draw_backend_fill:
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { f \bool_if:NT \g__draw_draw_eor_bool * }
   }
 \cs_new_protected:Npn \__draw_backend_fillstroke:
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { B \bool_if:NT \g__draw_draw_eor_bool * }
   }
 \cs_new_protected:Npn \__draw_backend_clip:
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { W \bool_if:NT \g__draw_draw_eor_bool * }
   }
 \cs_new_protected:Npn \__draw_backend_discardpath:
   { \__draw_backend_literal:n { n } }
 \cs_new_protected:Npn \__draw_backend_dash_pattern:nn #1#2
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       {
         [
           \exp_args:Nf \use:n
@@ -458,11 +462,11 @@
   { ~ \dim_to_decimal_in_bp:n {#1} }
 \cs_new_protected:Npn \__draw_backend_linewidth:n #1
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { \dim_to_decimal_in_bp:n {#1} ~ w }
   }
 \cs_new_protected:Npn \__draw_backend_miterlimit:n #1
-  { \__draw_backend_literal:x { #1 ~ M } }
+  { \__draw_backend_literal:e { #1 ~ M } }
 \cs_new_protected:Npn \__draw_backend_cap_butt:
   { \__draw_backend_literal:n { 0 ~ J } }
 \cs_new_protected:Npn \__draw_backend_cap_round:
@@ -509,7 +513,7 @@
   {
     \int_zero:N \l__graphics_page_int
     \tl_clear:N \l__graphics_pagebox_tl
-    \tl_set:Nx \l__graphics_attr_tl
+    \tl_set:Ne \l__graphics_attr_tl
       {
         \tl_if_empty:NF \l__graphics_decodearray_str
           { :D \l__graphics_decodearray_str }
@@ -526,7 +530,7 @@
   {
     \tl_clear:N \l__graphics_decodearray_str
     \bool_set_false:N \l__graphics_interpolate_bool
-    \tl_set:Nx \l__graphics_attr_tl
+    \tl_set:Ne \l__graphics_attr_tl
       {
         : \l__graphics_pagebox_tl
         \int_compare:nNnT \l__graphics_page_int > 1
@@ -538,7 +542,7 @@
   }
 \cs_new_protected:Npn \__graphics_backend_getbb_auxi:n #1
   {
-    \__graphics_bb_restore:xF { #1 \l__graphics_attr_tl }
+    \__graphics_bb_restore:eF { #1 \l__graphics_attr_tl }
       { \__graphics_backend_getbb_auxii:n {#1} }
   }
 \cs_new_protected:Npn \__graphics_backend_getbb_auxii:n #1
@@ -547,7 +551,7 @@
       { \__graphics_backend_dequote:w #1 " #1 " \s__graphics_stop }
     \int_const:cn { c__graphics_ #1 \l__graphics_attr_tl _int }
       { \tex_the:D \tex_pdflastximage:D }
-    \__graphics_bb_save:x { #1 \l__graphics_attr_tl }
+    \__graphics_bb_save:e { #1 \l__graphics_attr_tl }
   }
 \cs_new_protected:Npn \__graphics_backend_getbb_auxiii:n #1
   {
@@ -598,7 +602,7 @@
           \l__graphics_backend_dir_str
           \l__graphics_backend_name_str
           \l__graphics_backend_ext_str
-        \exp_args:Nx \__graphics_backend_getbb_eps:nn
+        \exp_args:Ne \__graphics_backend_getbb_eps:nn
           {
             \exp_args:Ne \__kernel_file_name_quote:n
               {
@@ -624,7 +628,7 @@
       {
         \file_parse_full_name:nNNN {#1}
           \l__graphics_backend_dir_str \l__graphics_backend_name_str \l__graphics_backend_ext_str
-        \exp_args:Nx \__graphics_backend_include_pdf:n
+        \exp_args:Ne \__graphics_backend_include_pdf:n
           {
             \exp_args:Ne \__kernel_file_name_quote:n
               {
@@ -652,7 +656,7 @@
       depth  ~ \dim_eval:n {#3} ~
       {#4}
   }
-\cs_new:Npx \__pdf_backend_annotation_last:
+\cs_new:Npe \__pdf_backend_annotation_last:
   {
     \exp_not:N \int_value:w
       \exp_not:N \tex_pdflastannot:D
@@ -672,7 +676,7 @@
   {
     \tex_pdfendlink:D
   }
-\cs_new:Npx \__pdf_backend_link_last:
+\cs_new:Npe \__pdf_backend_link_last:
   {
     \exp_not:N \int_value:w
       \exp_not:N \tex_pdflastlink:D
@@ -757,7 +761,7 @@
             }
         }
   }
-\cs_generate_variant:Nn \__pdf_backend_object_write:nnn { nnx }
+\cs_generate_variant:Nn \__pdf_backend_object_write:nnn { nne }
 \cs_new:Npn \__pdf_exp_not_i:nn #1#2 { \exp_not:n {#1} }
 \cs_new:Npn \__pdf_exp_not_ii:nn #1#2 { \exp_not:n {#2} }
 \cs_new_protected:Npn \__pdf_backend_object_now:nn #1#2
@@ -765,14 +769,14 @@
     \tex_immediate:D \tex_pdfobj:D
       \__pdf_backend_object_write:nn {#1} {#2}
   }
-\cs_generate_variant:Nn \__pdf_backend_object_now:nn { nx }
-\cs_new:Npx \__pdf_backend_object_last:
+\cs_generate_variant:Nn \__pdf_backend_object_now:nn { ne }
+\cs_new:Npe \__pdf_backend_object_last:
   {
     \exp_not:N \int_value:w
       \exp_not:N \tex_pdflastobj:D
       \c_space_tl 0 ~ R
   }
-\cs_new:Npx \__pdf_backend_pageobject_ref:n #1
+\cs_new:Npe \__pdf_backend_pageobject_ref:n #1
   {
     \exp_not:N \int_value:w
       \exp_not:N \tex_pdfpageref:D
@@ -796,7 +800,7 @@
       \tex_pdfobjcompresslevel:D
         #1 \scan_stop:
   }
-\cs_new_protected:Npx \__pdf_backend_version_major_gset:n #1
+\cs_new_protected:Npe \__pdf_backend_version_major_gset:n #1
   {
     \cs_if_exist:NT \tex_pdfmajorversion:D
       {
@@ -810,7 +814,7 @@
       \tex_pdfminorversion:D
         \int_eval:n {#1} \scan_stop:
   }
-\cs_new:Npx \__pdf_backend_version_major:
+\cs_new:Npe \__pdf_backend_version_major:
   {
     \cs_if_exist:NTF \tex_pdfmajorversion:D
       { \exp_not:N \tex_the:D \tex_pdfmajorversion:D }
@@ -844,7 +848,7 @@
 \tl_new:N \l__opacity_backend_stroke_tl
 \cs_new_protected:Npn \__opacity_backend_select:n #1
  {
-   \exp_args:Nx \__opacity_backend_select_aux:n
+   \exp_args:Ne \__opacity_backend_select_aux:n
      { \fp_eval:n { min(max(0,#1),1) } }
  }
 \cs_new_protected:Npn \__opacity_backend_select_aux:n #1
@@ -870,13 +874,13 @@
  }
 \cs_new_protected:Npn \__opacity_backend_fill:n #1
   {
-    \__opacity_backend_fill_stroke:xx
+    \__opacity_backend_fill_stroke:ee
       { \fp_eval:n { min(max(0,#1),1) } }
       \l__opacity_backend_stroke_tl
   }
 \cs_new_protected:Npn \__opacity_backend_stroke:n #1
   {
-    \__opacity_backend_fill_stroke:xx
+    \__opacity_backend_fill_stroke:ee
       \l__opacity_backend_fill_tl
       { \fp_eval:n { min(max(0,#1),1) } }
   }
@@ -898,7 +902,7 @@
         \group_insert_after:N \__opacity_backend_reset:
       }
   }
-\cs_generate_variant:Nn \__opacity_backend_fill_stroke:nn { xx }
+\cs_generate_variant:Nn \__opacity_backend_fill_stroke:nn { ee }
 %% 
 %%
 %% End of file `l3backend-pdftex.def'.
diff --git a/Master/texmf-dist/tex/latex/l3backend/l3backend-xetex.def b/Master/texmf-dist/tex/latex/l3backend/l3backend-xetex.def
index 1f9966125c4..acdc2e7942f 100644
--- a/Master/texmf-dist/tex/latex/l3backend/l3backend-xetex.def
+++ b/Master/texmf-dist/tex/latex/l3backend/l3backend-xetex.def
@@ -26,7 +26,7 @@
 %% 
 %% File: l3backend-basics.dtx
 \ProvidesExplFile
-  {l3backend-xetex.def}{2023-04-19}{}
+  {l3backend-xetex.def}{2023-10-10}{}
   {L3 backend support: XeTeX}
 \cs_if_exist:NTF \__kernel_dependency_version_check:nn
   {
@@ -45,7 +45,6 @@
 \cs_new_eq:NN \__kernel_backend_literal:e \tex_special:D
 \cs_new_protected:Npn \__kernel_backend_literal:n #1
   { \__kernel_backend_literal:e { \exp_not:n {#1} } }
-\cs_generate_variant:Nn \__kernel_backend_literal:n { x }
 \cs_if_exist:NTF \@ifl@t@r
   {
     \@ifl@t@r \fmtversion { 2020-10-01 }
@@ -58,7 +57,7 @@
   { \cs_new_eq:NN \__kernel_backend_first_shipout:n \use:n }
 \cs_new_protected:Npn \__kernel_backend_literal_pdf:n #1
   { \__kernel_backend_literal:n { pdf:literal~ #1 } }
-\cs_generate_variant:Nn \__kernel_backend_literal_pdf:n { x }
+\cs_generate_variant:Nn \__kernel_backend_literal_pdf:n { e }
 \cs_new_protected:Npn \__kernel_backend_literal_page:n #1
   { \__kernel_backend_literal:n { pdf:literal~direct~ #1 } }
 \cs_new_protected:Npn \__kernel_backend_scope_begin:
@@ -82,7 +81,7 @@
 \msg_new:nnn { color } { unknown-named-color }
   { Named~color~'#1'~is~not~known. }
 \prop_new:N \g__color_backend_colorant_prop
-\cs_new:Npx \__color_backend_devicen_colorants:n #1
+\cs_new:Npe \__color_backend_devicen_colorants:n #1
   {
     \exp_not:N \tl_if_blank:nF {#1}
       {
@@ -108,7 +107,7 @@
     \__color_backend_devicen_colorants:w
   }
 \cs_new_protected:Npn \__color_backend_select_separation:nn #1#2
-  { \__kernel_backend_literal:x { pdf : bc ~ \pdf_object_ref:n {#1} ~ [ #2 ] } }
+  { \__kernel_backend_literal:e { pdf : bc ~ \pdf_object_ref:n {#1} ~ [ #2 ] } }
 \cs_new_eq:NN \__color_backend_select_devicen:nn \__color_backend_select_separation:nn
 \cs_new_eq:NN \__color_backend_select_iccbased:nn \__color_backend_select_separation:nn
 \cs_new_protected:Npn \__color_backend_init_resource:n #1
@@ -116,7 +115,7 @@
   }
 \cs_new_protected:Npn \__color_backend_separation_init:nnnnn #1#2#3#4#5
   {
-    \pdf_object_unnamed_write:nx { dict }
+    \pdf_object_unnamed_write:ne { dict }
       {
         /FunctionType ~ 2
         /Domain ~ [0 ~ 1]
@@ -124,19 +123,19 @@
         /C0 ~ [#4] ~
         /C1 ~ [#5] /N ~ 1
       }
-    \exp_args:Nx \__color_backend_separation_init:nn
+    \exp_args:Ne \__color_backend_separation_init:nn
       { \str_convert_pdfname:n {#1} } {#2}
     \__color_backend_init_resource:n { color \int_use:N \g__color_model_int }
   }
 \cs_new_protected:Npn \__color_backend_separation_init:nn #1#2
   {
-    \use:x
+    \use:e
       {
         \pdf_object_new:n { color \int_use:N \g__color_model_int }
         \pdf_object_write:nnn { color \int_use:N \g__color_model_int } { array }
           { /Separation /#1 ~ #2 ~ \pdf_object_ref_last: }
       }
-    \prop_gput:Nnx \g__color_backend_colorant_prop { /#1 }
+    \prop_gput:Nne \g__color_backend_colorant_prop { /#1 }
       { \pdf_object_ref_last: }
   }
 \cs_new_protected:Npn \__color_backend_separation_init_CIELAB:nnn #1#2#3
@@ -144,7 +143,7 @@
     \pdf_object_if_exist:nF { __color_illuminant_CIELAB_ #1 }
       {
         \pdf_object_new:n { __color_illuminant_CIELAB_ #1 }
-        \pdf_object_write:nnx { __color_illuminant_CIELAB_ #1 } { array }
+        \pdf_object_write:nne { __color_illuminant_CIELAB_ #1 } { array }
           {
             /Lab ~
             <<
@@ -163,7 +162,7 @@
   }
 \cs_new_protected:Npn \__color_backend_devicen_init:nnn #1#2#3
   {
-    \pdf_object_unnamed_write:nx { stream }
+    \pdf_object_unnamed_write:ne { stream }
       {
         {
           /FunctionType ~ 4 ~
@@ -185,7 +184,7 @@
         }
         { {#3} }
      }
-    \use:x
+    \use:e
       {
         \pdf_object_new:n { color \int_use:N \g__color_model_int }
         \pdf_object_write:nnn { color \int_use:N \g__color_model_int } { array }
@@ -210,7 +209,7 @@
     \pdf_object_if_exist:nF { __color_icc_ #1 }
       {
         \pdf_object_new:n { __color_icc_ #1 }
-        \pdf_object_write:nnx { __color_icc_ #1 } { fstream }
+        \pdf_object_write:nne { __color_icc_ #1 } { fstream }
           {
             {
               /N ~ \exp_not:n { #2 } ~
@@ -219,7 +218,7 @@
             {#1}
           }
       }
-    \pdf_object_unnamed_write:nx { array }
+    \pdf_object_unnamed_write:ne { array }
       { /ICCBased ~ \pdf_object_ref:n { __color_icc_ #1 } }
     \__color_backend_init_resource:n { color \int_use:N \g__color_model_int }
   }
@@ -234,7 +233,7 @@
             {#1}
           }
       }
-    \pdf_object_unnamed_write:nx { array }
+    \pdf_object_unnamed_write:ne { array }
       { /ICCBased ~ \pdf_object_ref:n { __color_icc_ #1 } }
     \__color_backend_init_resource:n { Default #2 }
   }
@@ -250,12 +249,12 @@
 \cs_new_eq:NN \__color_backend_stroke_rgb:n  \__color_backend_stroke:n
 \cs_new_protected:Npn \__color_backend_fill_separation:nn #1#2
   {
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       { pdf : bc ~ fill ~ \pdf_object_ref:n {#1} ~ [ #2 ] }
   }
 \cs_new_protected:Npn \__color_backend_stroke_separation:nn #1#2
   {
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       { pdf : bc ~ stroke ~ \pdf_object_ref:n {#1} ~ [ #2 ] }
   }
 \cs_new_eq:NN \__color_backend_fill_devicen:nn \__color_backend_fill_separation:nn
@@ -266,7 +265,7 @@
 \cs_new_protected:Npn \__box_backend_clip:N #1
   {
     \__kernel_backend_scope_begin:
-    \__kernel_backend_literal_pdf:x
+    \__kernel_backend_literal_pdf:e
       {
         0~
         \dim_to_decimal_in_bp:n { -\box_dp:N #1 } ~
@@ -283,7 +282,7 @@
 \cs_new_protected:Npn \__box_backend_rotate_aux:Nn #1#2
   {
     \__kernel_backend_scope_begin:
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       {
         x:rotate~
         \fp_compare:nNnTF {#2} = \c_zero_fp
@@ -296,7 +295,7 @@
 \cs_new_protected:Npn \__box_backend_scale:Nnn #1#2#3
   {
     \__kernel_backend_scope_begin:
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       {
         x:scale~
         \fp_eval:n { round ( #2 , 5 ) } ~
@@ -307,7 +306,7 @@
   }
 %% File: l3backend-draw.dtx
 \cs_new_eq:NN \__draw_backend_literal:n \__kernel_backend_literal_pdf:n
-\cs_generate_variant:Nn \__draw_backend_literal:n { x }
+\cs_generate_variant:Nn \__draw_backend_literal:n { e }
 \cs_new_protected:Npn \__draw_backend_begin:
   { \__draw_backend_scope_begin: }
 \cs_new_protected:Npn \__draw_backend_end:
@@ -316,17 +315,17 @@
 \cs_new_eq:NN \__draw_backend_scope_end: \__kernel_backend_scope_end:
 \cs_new_protected:Npn \__draw_backend_moveto:nn #1#2
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~ m }
   }
 \cs_new_protected:Npn \__draw_backend_lineto:nn #1#2
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~ l }
   }
 \cs_new_protected:Npn \__draw_backend_curveto:nnnnnn #1#2#3#4#5#6
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       {
         \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~
         \dim_to_decimal_in_bp:n {#3} ~ \dim_to_decimal_in_bp:n {#4} ~
@@ -336,7 +335,7 @@
  }
 \cs_new_protected:Npn \__draw_backend_rectangle:nnnn #1#2#3#4
   {
-     \__draw_backend_literal:x
+     \__draw_backend_literal:e
       {
         \dim_to_decimal_in_bp:n {#1} ~ \dim_to_decimal_in_bp:n {#2} ~
         \dim_to_decimal_in_bp:n {#3} ~ \dim_to_decimal_in_bp:n {#4} ~
@@ -356,24 +355,24 @@
   { \__draw_backend_literal:n { s } }
 \cs_new_protected:Npn \__draw_backend_fill:
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { f \bool_if:NT \g__draw_draw_eor_bool * }
   }
 \cs_new_protected:Npn \__draw_backend_fillstroke:
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { B \bool_if:NT \g__draw_draw_eor_bool * }
   }
 \cs_new_protected:Npn \__draw_backend_clip:
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { W \bool_if:NT \g__draw_draw_eor_bool * }
   }
 \cs_new_protected:Npn \__draw_backend_discardpath:
   { \__draw_backend_literal:n { n } }
 \cs_new_protected:Npn \__draw_backend_dash_pattern:nn #1#2
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       {
         [
           \exp_args:Nf \use:n
@@ -386,11 +385,11 @@
   { ~ \dim_to_decimal_in_bp:n {#1} }
 \cs_new_protected:Npn \__draw_backend_linewidth:n #1
   {
-    \__draw_backend_literal:x
+    \__draw_backend_literal:e
       { \dim_to_decimal_in_bp:n {#1} ~ w }
   }
 \cs_new_protected:Npn \__draw_backend_miterlimit:n #1
-  { \__draw_backend_literal:x { #1 ~ M } }
+  { \__draw_backend_literal:e { #1 ~ M } }
 \cs_new_protected:Npn \__draw_backend_cap_butt:
   { \__draw_backend_literal:n { 0 ~ J } }
 \cs_new_protected:Npn \__draw_backend_cap_round:
@@ -410,20 +409,20 @@
   }
 \cs_new_protected:Npn \__draw_backend_cm_aux:nnnn #1#2#3#4
   {
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       {
         x:rotate~
         \fp_compare:nNnTF {#1} = \c_zero_fp
           { 0 }
           { \fp_eval:n { round ( -#1 , 5 ) } }
       }
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       {
         x:scale~
         \fp_eval:n { round ( #2 , 5 ) } ~
         \fp_eval:n { round ( #3 , 5 ) }
       }
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       {
         x:rotate~
         \fp_compare:nNnTF {#4} = \c_zero_fp
@@ -433,7 +432,7 @@
   }
 \cs_new_protected:Npn \__draw_backend_cm_decompose:nnnnN #1#2#3#4#5
   {
-    \use:x
+    \use:e
       {
         \__draw_backend_cm_decompose_auxi:nnnnN
           { \fp_eval:n { (#1 + #4) / 2 } }
@@ -445,7 +444,7 @@
   }
 \cs_new_protected:Npn \__draw_backend_cm_decompose_auxi:nnnnN #1#2#3#4#5
   {
-    \use:x
+    \use:e
       {
         \__draw_backend_cm_decompose_auxii:nnnnN
           { \fp_eval:n { 2 * sqrt ( #1 * #1 + #4 * #4 ) } }
@@ -457,7 +456,7 @@
   }
 \cs_new_protected:Npn \__draw_backend_cm_decompose_auxii:nnnnN #1#2#3#4#5
   {
-    \use:x
+    \use:e
       {
         \__draw_backend_cm_decompose_auxiii:nnnnN
           { \fp_eval:n { ( #4 - #3 ) / 2 } }
@@ -507,7 +506,7 @@
 \int_new:N \g__graphics_track_int
 \cs_new_protected:Npn \__graphics_backend_include_eps:n #1
   {
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       {
         PSfile = #1 \c_space_tl
         llx = \dim_to_decimal_in_bp:n \l__graphics_llx_dim \c_space_tl
@@ -524,7 +523,7 @@
 \cs_new_eq:NN \__graphics_backend_include_bmp:n \__graphics_backend_include_jpg:n
 \cs_new_protected:Npn \__graphics_backend_include_auxi:nn #1#2
   {
-    \__graphics_backend_include_auxii:xnn
+    \__graphics_backend_include_auxii:enn
       {
         \tl_if_empty:NF \l__graphics_pagebox_tl
           { : \l__graphics_pagebox_tl }
@@ -541,17 +540,17 @@
   {
     \int_if_exist:cTF { c__graphics_ #2#1 _int }
       {
-        \__kernel_backend_literal:x
+        \__kernel_backend_literal:e
           { pdf:usexobj~@graphic \int_use:c { c__graphics_ #2#1 _int } }
       }
       { \__graphics_backend_include_auxiii:nnn {#2} {#1} {#3} }
   }
-\cs_generate_variant:Nn \__graphics_backend_include_auxii:nnn { x }
+\cs_generate_variant:Nn \__graphics_backend_include_auxii:nnn { e }
 \cs_new_protected:Npn \__graphics_backend_include_auxiii:nnn #1#2#3
   {
     \int_gincr:N \g__graphics_track_int
     \int_const:cn { c__graphics_ #1#2 _int } { \g__graphics_track_int }
-    \__kernel_backend_literal:x
+    \__kernel_backend_literal:e
       {
         pdf:#3~
         @graphic \int_use:c { c__graphics_ #1#2 _int } ~
@@ -613,7 +612,7 @@
   }
 \cs_new_protected:Npn \__graphics_backend_getbb_auxiv:nnNnn #1#2#3#4#5
   {
-    \use:x
+    \use:e
       {
         \__graphics_backend_getbb_auxv:nNnn {#2} #3 { : #1 #4 }
           {
@@ -655,9 +654,9 @@
   }
 %% File: l3backend-pdf.dtx
 \box_new:N \l__pdf_internal_box
-\cs_new_protected:Npx \__pdf_backend:n #1
+\cs_new_protected:Npe \__pdf_backend:n #1
   { \__kernel_backend_literal:n { pdf: #1 } }
-\cs_generate_variant:Nn \__pdf_backend:n { x }
+\cs_generate_variant:Nn \__pdf_backend:n { e }
 \cs_new_protected:Npn \__pdf_backend_catalog_gput:nn #1#2
   { \__pdf_backend:n { put ~ @catalog << /#1 ~ #2 >> } }
 \cs_new_protected:Npn \__pdf_backend_info_gput:nn #1#2
@@ -678,15 +677,15 @@
     \use:c { __pdf_backend_object_write_ #2 :nn }
       { \__pdf_backend_object_ref:n {#1} } {#3}
   }
-\cs_generate_variant:Nn \__pdf_backend_object_write:nnn { nnx }
+\cs_generate_variant:Nn \__pdf_backend_object_write:nnn { nne }
 \cs_new_protected:Npn \__pdf_backend_object_write_array:nn #1#2
   {
-    \__pdf_backend:x
+    \__pdf_backend:e
       { obj ~ #1 ~ [ ~ \exp_not:n {#2} ~ ] }
   }
 \cs_new_protected:Npn \__pdf_backend_object_write_dict:nn #1#2
   {
-    \__pdf_backend:x
+    \__pdf_backend:e
       { obj ~ #1 ~ << ~ \exp_not:n {#2} ~ >> }
   }
 \cs_new_protected:Npn \__pdf_backend_object_write_fstream:nn #1#2
@@ -695,7 +694,7 @@
   { \__pdf_backend_object_write_stream:nnnn { } {#1} #2 }
 \cs_new_protected:Npn \__pdf_backend_object_write_stream:nnnn #1#2#3#4
   {
-    \__pdf_backend:x
+    \__pdf_backend:e
       {
         #1 stream ~ #2 ~
           ( \exp_not:n {#4} ) ~ << \exp_not:n {#3} >>
@@ -704,11 +703,11 @@
 \cs_new_protected:Npn \__pdf_backend_object_now:nn #1#2
   {
     \int_gincr:N \g__pdf_backend_object_int
-    \exp_args:Nnx \use:c { __pdf_backend_object_write_ #1 :nn }
+    \exp_args:Nne \use:c { __pdf_backend_object_write_ #1 :nn }
       { @pdf.obj \int_use:N \g__pdf_backend_object_int }
       {#2}
   }
-\cs_generate_variant:Nn \__pdf_backend_object_now:nn { nx }
+\cs_generate_variant:Nn \__pdf_backend_object_now:nn { ne }
 \cs_new:Npn \__pdf_backend_object_last:
  { @pdf.obj \int_use:N \g__pdf_backend_object_int }
 \cs_new:Npn \__pdf_backend_pageobject_ref:n #1
@@ -718,7 +717,7 @@
   {
     \int_gincr:N \g__pdf_backend_object_int
     \int_gset_eq:NN \g__pdf_backend_annotation_int \g__pdf_backend_object_int
-    \__pdf_backend:x
+    \__pdf_backend:e
       {
         ann ~ @pdf.obj \int_use:N \g__pdf_backend_object_int \c_space_tl
         width  ~ \dim_eval:n {#1} ~
@@ -734,10 +733,10 @@
   { \__pdf_backend_link_begin:n { #1 /Subtype /Link /A << /S /GoTo /D ( #2 ) >> } }
 \cs_new_protected:Npn \__pdf_backend_link_begin_user:nnw #1#2
   { \__pdf_backend_link_begin:n {#1#2} }
-\cs_new_protected:Npx \__pdf_backend_link_begin:n #1
+\cs_new_protected:Npe \__pdf_backend_link_begin:n #1
   {
     \exp_not:N \int_gincr:N \exp_not:N  \g__pdf_backend_link_int
-    \__pdf_backend:x
+    \__pdf_backend:e
       {
          bann ~
          @pdf.lnk
@@ -754,10 +753,10 @@
 \cs_new:Npn \__pdf_backend_link_last:
   { @pdf.lnk \int_use:N \g__pdf_backend_link_int }
 \cs_new_protected:Npn \__pdf_backend_link_margin:n #1
-  { \__kernel_backend_literal:x { dvipdfmx:config~g~ \dim_eval:n {#1} } }
+  { \__kernel_backend_literal:e { dvipdfmx:config~g~ \dim_eval:n {#1} } }
 \cs_new_protected:Npn \__pdf_backend_destination:nn #1#2
   {
-    \__pdf_backend:x
+    \__pdf_backend:e
       {
         dest ~ ( \exp_not:n {#1} )
         [
@@ -816,7 +815,7 @@
     \__kernel_kern:n { -#1 }
   }
 \cs_new_protected:Npn \__pdf_backend_compresslevel:n #1
-  { \__kernel_backend_literal:x { dvipdfmx:config~z~ \int_eval:n {#1} } }
+  { \__kernel_backend_literal:e { dvipdfmx:config~z~ \int_eval:n {#1} } }
 \cs_new_protected:Npn \__pdf_backend_compress_objects:n #1
   {
     \bool_if:nF {#1}
@@ -824,13 +823,13 @@
   }
 \cs_new_protected:Npn \__pdf_backend_version_major_gset:n #1
   {
-    \cs_gset:Npx \__pdf_backend_version_major: { \int_eval:n {#1} }
-    \__kernel_backend_literal:x { pdf:majorversion~ \__pdf_backend_version_major: }
+    \cs_gset:Npe \__pdf_backend_version_major: { \int_eval:n {#1} }
+    \__kernel_backend_literal:e { pdf:majorversion~ \__pdf_backend_version_major: }
   }
 \cs_new_protected:Npn \__pdf_backend_version_minor_gset:n #1
   {
-    \cs_gset:Npx \__pdf_backend_version_minor: { \int_eval:n {#1} }
-    \__kernel_backend_literal:x { pdf:minorversion~ \__pdf_backend_version_minor: }
+    \cs_gset:Npe \__pdf_backend_version_minor: { \int_eval:n {#1} }
+    \__kernel_backend_literal:e { pdf:minorversion~ \__pdf_backend_version_minor: }
   }
 \cs_new:Npn \__pdf_backend_version_major: { 1 }
 \cs_new:Npn \__pdf_backend_version_minor: { 5 }
@@ -855,7 +854,7 @@
 \tl_new:N \l__opacity_backend_stroke_tl
 \cs_new_protected:Npn \__opacity_backend_select:n #1
  {
-   \exp_args:Nx \__opacity_backend_select_aux:n
+   \exp_args:Ne \__opacity_backend_select_aux:n
      { \fp_eval:n { min(max(0,#1),1) } }
  }
 \cs_new_protected:Npn \__opacity_backend_select_aux:n #1
@@ -882,13 +881,13 @@
  }
 \cs_new_protected:Npn \__opacity_backend_fill:n #1
   {
-    \__opacity_backend_fill_stroke:xx
+    \__opacity_backend_fill_stroke:ee
       { \fp_eval:n { min(max(0,#1),1) } }
       \l__opacity_backend_stroke_tl
   }
 \cs_new_protected:Npn \__opacity_backend_stroke:n #1
   {
-    \__opacity_backend_fill_stroke:xx
+    \__opacity_backend_fill_stroke:ee
       \l__opacity_backend_fill_tl
       { \fp_eval:n { min(max(0,#1),1) } }
   }
@@ -910,7 +909,7 @@
         \group_insert_after:N \__opacity_backend_reset:
       }
   }
-\cs_generate_variant:Nn \__opacity_backend_fill_stroke:nn { xx }
+\cs_generate_variant:Nn \__opacity_backend_fill_stroke:nn { ee }
 %% 
 %%
 %% End of file `l3backend-xetex.def'.
diff --git a/Master/texmf-dist/tex/latex/l3experimental/l3benchmark/l3benchmark.sty b/Master/texmf-dist/tex/latex/l3experimental/l3benchmark/l3benchmark.sty
index 7bae352b6c0..209a440673c 100644
--- a/Master/texmf-dist/tex/latex/l3experimental/l3benchmark/l3benchmark.sty
+++ b/Master/texmf-dist/tex/latex/l3experimental/l3benchmark/l3benchmark.sty
@@ -20,7 +20,7 @@
 %% 
 %% File: l3benchmark.dtx
 \RequirePackage{expl3}
-\ProvidesExplPackage{l3benchmark}{2023-05-11}{}
+\ProvidesExplPackage{l3benchmark}{2023-10-10}{}
   {L3 Experimental benchmarking}
 \fp_new:N \g_benchmark_duration_target_fp
 \fp_gset:Nn \g_benchmark_duration_target_fp { 1 }
@@ -73,13 +73,13 @@
   }
 \cs_new_protected:Npn \__benchmark_raw_replicate_large:nnN #1#2
   {
-    \cs_set:Npx \__benchmark_tmp:w ##1 { \prg_replicate:nn { 5000 } {##1} }
+    \cs_set:Npe \__benchmark_tmp:w ##1 { \prg_replicate:nn { 5000 } {##1} }
     \exp_args:Nno \__benchmark_raw_replicate:nnN { #1 / 5000 }
       { \__benchmark_tmp:w {#2} }
   }
 \cs_new_protected:Npn \__benchmark_raw_replicate_small:nnN #1#2
   {
-    \cs_set:Npx \__benchmark_tmp:w ##1##2 { \prg_replicate:nn {#1} {##1} }
+    \cs_set:Npe \__benchmark_tmp:w ##1##2 { \prg_replicate:nn {#1} {##1} }
     \__benchmark_raw:nN { \__benchmark_tmp:w {#2} { } } \g__benchmark_time_int
     \exp_args:No \__benchmark_raw_replicate_aux:nnN
       { \int_use:N \g__benchmark_time_int } {#2}
@@ -192,7 +192,7 @@
   { \fp_to_tl:n { round(#2 * 1e-#1, 2) } e#1 }
 \cs_new_protected:Npn \__benchmark_display:
   {
-    \iow_term:x
+    \iow_term:e
       {
         \__benchmark_fp_to_tl:N \g_benchmark_time_fp \c_space_tl seconds \c_space_tl
         ( \__benchmark_fp_to_tl:N \g_benchmark_ops_fp \c_space_tl ops)
@@ -208,7 +208,7 @@
   }
 \cs_new_protected:Npn \benchmark_tic:
   {
-    \iow_term:x { \__benchmark_tictoc_prefix: TIC }
+    \iow_term:e { \__benchmark_tictoc_prefix: TIC }
     \exp_args:NNf \seq_gput_right:Nn \g__benchmark_tictoc_seq { \sys_timer: }
     \int_gincr:N \g__benchmark_tictoc_int
   }
@@ -223,7 +223,7 @@
     \int_gdecr:N \g__benchmark_tictoc_int
     \fp_gset:Nn \g_benchmark_time_fp
       { ( \sys_timer: - \l__benchmark_tictoc_pop_tl ) / 65536 }
-    \iow_term:x
+    \iow_term:e
       {
         \__benchmark_tictoc_prefix:
         TOC: \c_space_tl
diff --git a/Master/texmf-dist/tex/latex/l3experimental/l3bitset/l3bitset.sty b/Master/texmf-dist/tex/latex/l3experimental/l3bitset/l3bitset.sty
index ceaae9744b0..25ef3d28d92 100644
--- a/Master/texmf-dist/tex/latex/l3experimental/l3bitset/l3bitset.sty
+++ b/Master/texmf-dist/tex/latex/l3experimental/l3bitset/l3bitset.sty
@@ -19,7 +19,7 @@
 %% and all files in that bundle must be distributed together.
 %% 
 %% File: l3bitset.dtx
-\ProvidesExplPackage{l3bitset}{2023-05-11}{}
+\ProvidesExplPackage{l3bitset}{2023-10-10}{}
   {L3 Experimental bitset support}
 \cs_new_protected:Npn \bitset_new:N #1
   {
@@ -56,13 +56,13 @@
   \bitset_if_exist:c \str_if_exist:c
   { p , T , F , TF }
 \cs_new_protected:Npn \__bitset_set_true:Nn #1#2
-  { \__bitset_set:NNnN \str_set:Nx #1 {#2} 1 }
+  { \__bitset_set:NNnN \str_set:Ne #1 {#2} 1 }
 \cs_new_protected:Npn \__bitset_gset_true:Nn #1#2
-  { \__bitset_set:NNnN \str_gset:Nx #1 {#2} 1 }
+  { \__bitset_set:NNnN \str_gset:Ne #1 {#2} 1 }
 \cs_new_protected:Npn \__bitset_set_false:Nn #1#2
-  { \__bitset_set:NNnN \str_set:Nx #1 {#2} 0 }
+  { \__bitset_set:NNnN \str_set:Ne #1 {#2} 0 }
 \cs_new_protected:Npn \__bitset_gset_false:Nn #1#2
-  { \__bitset_set:NNnN \str_gset:Nx #1 {#2} 0 }
+  { \__bitset_set:NNnN \str_gset:Ne #1 {#2} 0 }
 \cs_new_protected:Npn \__bitset_set:NNnN #1#2#3#4
   {
     \int_compare:nNnT {#3} > { 0 }
@@ -126,7 +126,7 @@
             \prop_gput:cnn { g__bitset_ \cs_to_str:N #2 _name_prop } {#3} {#3}
           }
           {
-            \msg_warning:nnxx { bitset } { unknown-name }
+            \msg_warning:nnee { bitset } { unknown-name }
               { \token_to_str:N #2 }
               { \tl_to_str:n {#3} }
           }
@@ -185,11 +185,11 @@
   }
 \cs_generate_variant:Nn \bitset_item:Nn { c }
 
-\cs_new_protected:Npn   \bitset_show:N { \__bitset_show:NN \msg_show:nnxxxx }
+\cs_new_protected:Npn   \bitset_show:N { \__bitset_show:NN \msg_show:nneeee }
 \cs_generate_variant:Nn \bitset_show:N { c }
-\cs_new_protected:Npn   \bitset_log:N  { \__bitset_show:NN \msg_log:nnxxxx }
+\cs_new_protected:Npn   \bitset_log:N  { \__bitset_show:NN \msg_log:nneeee }
 \cs_generate_variant:Nn \bitset_log:N  { c }
-\cs_new_protected:Npn   \bitset_show_named_index:N { \__bitset_show_named_index:NN \msg_show:nnxxxx }
+\cs_new_protected:Npn   \bitset_show_named_index:N { \__bitset_show_named_index:NN \msg_show:nneeee }
 \cs_generate_variant:Nn \bitset_show_named_index:N { c }
 \cs_new_protected:Npn \__bitset_show:NN #1#2
   {
diff --git a/Master/texmf-dist/tex/latex/l3experimental/l3draw/l3draw.sty b/Master/texmf-dist/tex/latex/l3experimental/l3draw/l3draw.sty
index f82a7913338..cea22f9993d 100644
--- a/Master/texmf-dist/tex/latex/l3experimental/l3draw/l3draw.sty
+++ b/Master/texmf-dist/tex/latex/l3experimental/l3draw/l3draw.sty
@@ -28,7 +28,7 @@
 %% 
 %% File: l3draw.dtx
 \RequirePackage{expl3}
-\ProvidesExplPackage{l3draw}{2023-05-11}{}
+\ProvidesExplPackage{l3draw}{2023-10-10}{}
   {L3 Experimental core drawing support}
 \scan_new:N \s__draw_mark
 \scan_new:N \s__draw_stop
@@ -62,7 +62,7 @@
     \group_begin:
       \hbox_set:Nn \l__draw_tmp_box
         {
-          \use:x
+          \use:e
             {
               \__draw_backend_box_use:Nnnnn #1
                 { \fp_use:N \l__draw_matrix_a_fp }
@@ -329,7 +329,7 @@
   {
     \fp_set:Nn \l__draw_path_tmpa_fp { \c__draw_path_curveto_b_fp * #1 }
     \fp_set:Nn \l__draw_path_tmpb_fp { \c__draw_path_curveto_b_fp * #2 }
-    \use:x
+    \use:e
       {
          \__draw_path_mark_corner:
          \__draw_path_curveto:nnnnnn
@@ -365,7 +365,7 @@
   { \draw_path_arc:nnnn {#1} {#2} {#3} {#3} }
 \cs_new_protected:Npn \draw_path_arc:nnnn #1#2#3#4
   {
-    \use:x
+    \use:e
       {
         \__draw_path_arc:nnnn
           { \fp_eval:n {#1} }
@@ -412,7 +412,7 @@
   }
 \cs_new_protected:Npn \__draw_path_arc_auxi:nnnnNnn #1#2#3#4#5#6#7
   {
-    \use:x
+    \use:e
       {
         \__draw_path_arc_auxii:nnnNnnnn
           {#1} {#2} {#4} #5 {#6} {#7}
@@ -493,7 +493,7 @@
   }
 \cs_new_protected:Npn \__draw_path_arc_aux_add:nn #1#2
   {
-    \tl_put_right:Nx \l__draw_path_tmp_tl
+    \tl_put_right:Ne \l__draw_path_tmp_tl
       { { \fp_to_dim:n {#1} } { \fp_to_dim:n {#2} } }
   }
 \fp_new:N \l__draw_path_arc_delta_fp
@@ -517,7 +517,7 @@
   }
 \cs_new_protected:Npn \__draw_path_ellipse:nnnnnn #1#2#3#4#5#6
   {
-    \use:x
+    \use:e
       {
         \__draw_path_moveto:nn
           { \fp_to_dim:n { #1 + #3 } } { \fp_to_dim:n { #2 + #4 } }
@@ -1356,7 +1356,7 @@
   {
     \bool_if:NTF \l__draw_baseline_bool
       {
-        \use:x
+        \use:e
           {
             \exp_not:n {#1}
             \__draw_finalise_baseline:n { \dim_use:N \l__draw_baseline_dim }
@@ -1422,7 +1422,7 @@
 \bool_new:N \g__draw_softpath_corners_bool
 \cs_new_protected:Npn \__draw_softpath_add:n
   { \tl_build_gput_right:Nn \g__draw_softpath_main_tl }
-\cs_generate_variant:Nn \__draw_softpath_add:n { o, x }
+\cs_generate_variant:Nn \__draw_softpath_add:n { o, e }
 \cs_new_protected:Npn \__draw_softpath_use:
   {
     \tl_build_get:NN \g__draw_softpath_main_tl \l__draw_softpath_internal_tl
@@ -1439,7 +1439,7 @@
 \bool_gset_true:N \g__draw_softpath_move_bool
 \cs_new_protected:Npn \__draw_softpath_closepath:
   {
-    \__draw_softpath_add:x
+    \__draw_softpath_add:e
       {
         \__draw_softpath_close_op:nn
           { \dim_use:N \g__draw_softpath_lastx_dim }
@@ -1638,13 +1638,13 @@
   }
 \cs_new_protected:Npn \__draw_softpath_round_calc:NnnNnn #1#2#3#4#5#6
   {
-    \tl_set:Nx \l__draw_softpath_curve_end_tl
+    \tl_set:Ne \l__draw_softpath_curve_end_tl
       {
         \draw_point_interpolate_distance:nnn
           \l__draw_softpath_cornerii_dim
           { #5 , #6 } { #2 , #3 }
       }
-    \tl_put_right:Nx \l__draw_softpath_part_tl
+    \tl_put_right:Ne \l__draw_softpath_part_tl
       {
         \exp_not:N #4
         \__draw_softpath_round_calc:fVnnnn
@@ -1697,11 +1697,11 @@
   }
 \cs_new_protected:Npn \__draw_softpath_round_close:nn #1#2
   {
-    \use:x
+    \use:e
       {
         \__draw_softpath_round_calc:NnnNnn
           {
-            \tl_set:Nx \exp_not:N \l__draw_softpath_move_tl
+            \tl_set:Ne \exp_not:N \l__draw_softpath_move_tl
               {
                 \__draw_softpath_moveto_op:nn
                 \exp_not:N \exp_after:wN
@@ -1709,7 +1709,7 @@
                   \exp_not:N \l__draw_softpath_curve_end_tl
                     \s__draw_stop
               }
-            \use:x
+            \use:e
               {
                 \exp_not:N \exp_not:N \exp_not:N \use_i:nnnn
                   {
@@ -1752,7 +1752,7 @@
       \seq_set_from_clist:Nn \l__draw_tmp_seq {#1}
       \seq_set_map:NNn \l__draw_tmp_seq \l__draw_tmp_seq
         { \fp_to_dim:n {##1} }
-      \use:x
+      \use:e
         {
           \__draw_backend_dash_pattern:nn
             { \seq_use:Nn \l__draw_tmp_seq { , } }
@@ -1762,7 +1762,7 @@
   }
 \seq_new:N \l__draw_tmp_seq
 \cs_new_protected:Npn \draw_miterlimit:n #1
-  { \exp_args:Nx \__draw_backend_miterlimit:n { \fp_eval:n {#1} } }
+  { \exp_args:Ne \__draw_backend_miterlimit:n { \fp_eval:n {#1} } }
 \cs_new_protected:Npn \draw_cap_butt: { \__draw_backend_cap_butt: }
 \cs_new_protected:Npn \draw_cap_rectangle: { \__draw_backend_cap_rectangle: }
 \cs_new_protected:Npn \draw_cap_round: { \__draw_backend_cap_round: }
@@ -1821,7 +1821,7 @@
   }
 \cs_new_protected:Npn \draw_transform_matrix:nnnn #1#2#3#4
   {
-    \use:x
+    \use:e
       {
         \__draw_transform:nnnn
           { \fp_eval:n {#1} }
@@ -1832,7 +1832,7 @@
   }
 \cs_new_protected:Npn \__draw_transform:nnnn #1#2#3#4
   {
-    \use:x
+    \use:e
       {
         \draw_transform_matrix_absolute:nnnn
           { #1 * \l__draw_matrix_a_fp + #2 * \l__draw_matrix_c_fp }
@@ -1897,7 +1897,7 @@
   }
 \cs_new_protected:Npn \__draw_transform_triangle:nnnnnn #1#2#3#4#5#6
   {
-    \use:x
+    \use:e
       {
         \draw_transform_matrix_absolute:nnnn
           { #3 - #1 }
diff --git a/Master/texmf-dist/tex/latex/l3experimental/l3graphics/l3graphics.sty b/Master/texmf-dist/tex/latex/l3experimental/l3graphics/l3graphics.sty
index bc32919cfe3..2c54e34557b 100644
--- a/Master/texmf-dist/tex/latex/l3experimental/l3graphics/l3graphics.sty
+++ b/Master/texmf-dist/tex/latex/l3experimental/l3graphics/l3graphics.sty
@@ -19,7 +19,7 @@
 %% and all files in that bundle must be distributed together.
 %% 
 %% File: l3graphics.dtx
-\ProvidesExplPackage{l3graphics}{2023-05-11}{}
+\ProvidesExplPackage{l3graphics}{2023-10-10}{}
   {L3 Experimental graphics inclusion support}
 \dim_new:N \l__graphics_internal_dim
 \ior_new:N \l__graphics_internal_ior
@@ -37,8 +37,8 @@
     pagebox .choices:nn =
       { art , bleed , crop , media , trim }
       {
-        \tl_set:Nx \l__graphics_pagebox_tl
-           { \tl_use:N \l_keys_choice_tl box }
+        \tl_set:Ne \l__graphics_pagebox_tl
+           { \l_keys_choice_tl box }
       } ,
     pagebox .initial:n =
       crop ,
@@ -66,7 +66,7 @@
         \dim_const:cn { c__graphics_ #1 _ury_dim } { \l__graphics_ury_dim }
       }
   }
-\cs_generate_variant:Nn \__graphics_bb_save:n { x }
+\cs_generate_variant:Nn \__graphics_bb_save:n { e }
 \cs_new_protected:Npn \__graphics_bb_restore:nF #1#2
   {
     \dim_if_exist:cTF { c__graphics_ #1 _urx_dim }
@@ -82,7 +82,7 @@
       }
       {#2}
   }
-\cs_generate_variant:Nn \__graphics_bb_restore:nF { x }
+\cs_generate_variant:Nn \__graphics_bb_restore:nF { e }
 \cs_new_protected:Npn \__graphics_extract_bb:n #1
   {
     \int_compare:nNnTF \l__graphics_page_int > 0
@@ -119,7 +119,7 @@
     \__graphics_bb_restore:nF {#1#2}
       { \__graphics_read_bb_auxii:nnnn {#3} {#4} {#1} {#2} }
   }
-\cs_new_protected:Npx \__graphics_read_bb_auxii:nnnn #1#2#3#4
+\cs_new_protected:Npe \__graphics_read_bb_auxii:nnnn #1#2#3#4
   {
     #1
     \exp_not:N \ior_if_eof:NTF \exp_not:N \l__graphics_internal_ior
@@ -134,22 +134,22 @@
       }
     \ior_close:N \exp_not:N \l__graphics_internal_ior
   }
-\use:x
+\use:e
   {
     \cs_new_protected:Npn \exp_not:N \__graphics_read_bb_auxiii:w
-      ##1 \c_colon_str ##2 \s__graphics_stop
+      #1 \c_colon_str #2 \s__graphics_stop
       {
         \exp_not:N \str_if_eq:nnT
           { \c_percent_str \c_percent_str BoundingBox }
-          {##1}
-          { \exp_not:N \__graphics_read_bb_auxiv:w ##2 ( ) \s__graphics_stop }
+          {#1}
+          { \exp_not:N \__graphics_read_bb_auxiv:w #2 ( ) \s__graphics_stop }
       }
   }
 \cs_new_protected:Npn \__graphics_read_bb_auxiv:w #1 ( #2 ) #3 \s__graphics_stop
   {
     \str_if_eq:nnF {#2} { atend }
       {
-        \tl_set_rescan:Nnx \l__graphics_internal_tl
+        \tl_set_rescan:Nne \l__graphics_internal_tl
           {
             \char_set_catcode_space:n {  9 }
             \char_set_catcode_space:n { 32 }
@@ -219,7 +219,7 @@
     \cs_if_exist:cTF { __graphics_backend_include_ #1 :n }
       {
         \tl_set_eq:NN \l__graphics_final_name_str \l__graphics_full_name_str
-        \str_set:Nx \l__graphics_full_name_str
+        \str_set:Ne \l__graphics_full_name_str
          { \exp_args:NV \__kernel_file_name_quote:n \l__graphics_full_name_str }
         \exp_args:NnV \use:c { __graphics_backend_getbb_ #1 :n }
           \l__graphics_full_name_str
@@ -272,8 +272,8 @@
       { \l__graphics_urx_dim - \l__graphics_llx_dim }
     \box_use_drop:N \l__graphics_internal_box
   }
-\cs_new_protected:Npn \graphics_show_list: { \__graphics_list:N \msg_show:nnxxxx }
-\cs_new_protected:Npn \graphics_log_list: { \__graphics_list:N \msg_log:nnxxxx }
+\cs_new_protected:Npn \graphics_show_list: { \__graphics_list:N \msg_show:nneeee }
+\cs_new_protected:Npn \graphics_log_list: { \__graphics_list:N \msg_log:nneeee }
 \cs_new_protected:Npn \__graphics_list:N #1
   {
     \seq_remove_duplicates:N \g__graphics_record_seq
@@ -345,7 +345,7 @@
     \exp_args:NNNV \group_end:
     \tl_set:Nn #2 #2
   }
-\cs_new_protected:Npx \__graphics_get_pagecount:n #1
+\cs_new_protected:Npe \__graphics_get_pagecount:n #1
   {
     \ior_shell_open:Nn \exp_not:N \l__graphics_internal_ior
       { extractbb~-O~#1 }
@@ -362,16 +362,16 @@
       }
     \ior_close:N \exp_not:N \l__graphics_internal_ior
   }
-\use:x
+\use:e
   {
     \cs_new_protected:Npn \exp_not:N \__graphics_get_pagecount:nw
-      ##1##2 \c_colon_str ##3 \c_colon_str ##4 \s__graphics_stop
+      #1#2 \c_colon_str #3 \c_colon_str #4 \s__graphics_stop
       {
         \exp_not:N \str_if_eq:nnT
           { \c_percent_str \c_percent_str Pages }
-          {##2}
+          {#2}
           {
-            \int_const:cn { c__graphics_ ##1 _pages_int } {##3}
+            \int_const:cn { c__graphics_ #1 _pages_int } {#3}
             \exp_not:N \ior_map_break:
           }
       }
diff --git a/Master/texmf-dist/tex/latex/l3experimental/l3opacity/l3opacity.sty b/Master/texmf-dist/tex/latex/l3experimental/l3opacity/l3opacity.sty
index 2d0fc6b2df9..610407cb77e 100644
--- a/Master/texmf-dist/tex/latex/l3experimental/l3opacity/l3opacity.sty
+++ b/Master/texmf-dist/tex/latex/l3experimental/l3opacity/l3opacity.sty
@@ -20,7 +20,7 @@
 %% 
 %% File: l3opacity.dtx
 \RequirePackage{expl3}
-\ProvidesExplPackage{l3opacity}{2023-05-11}{}
+\ProvidesExplPackage{l3opacity}{2023-10-10}{}
   {L3 Experimental opacity support}
 \cs_new_protected:Npn \opacity_select:n #1
   { \__opacity_select:nN {#1} \__opacity_backend_select:n }
diff --git a/Master/texmf-dist/tex/latex/l3experimental/l3str/l3str-format.sty b/Master/texmf-dist/tex/latex/l3experimental/l3str/l3str-format.sty
index 59b99914d8e..16faf6a9ff7 100644
--- a/Master/texmf-dist/tex/latex/l3experimental/l3str/l3str-format.sty
+++ b/Master/texmf-dist/tex/latex/l3experimental/l3str/l3str-format.sty
@@ -20,7 +20,7 @@
 %% 
 %% File: l3str-format.dtx
 \RequirePackage{expl3}
-\ProvidesExplPackage{l3str-format}{2023-05-11}{}
+\ProvidesExplPackage{l3str-format}{2023-10-10}{}
   {L3 Experimental string formatting}
 \cs_generate_variant:Nn \use:nn { nf }
 \cs_generate_variant:Nn \use:nnn { fnf }
@@ -51,7 +51,7 @@
     \exp_last_unbraced:Nf \__str_format_parse_auxi:NN
       { \__kernel_str_to_other:n {#1} } \s__str_stop \s__str_stop {#1}
   }
-\cs_new:Npx \__str_format_parse_auxi:NN #1#2
+\cs_new:Npe \__str_format_parse_auxi:NN #1#2
   {
     \exp_not:N \__str_format_if_in:nNTF { < > = ^ } #2
       { \exp_not:N \__str_format_parse_auxiii:nN { #1 #2 } }
@@ -66,7 +66,7 @@
       { \__str_format_parse_auxiii:nN { #1 #2 } }
       { \__str_format_parse_auxiii:nN { #1 ? } #2 }
   }
-\cs_new:Npx \__str_format_parse_auxiii:nN #1#2
+\cs_new:Npe \__str_format_parse_auxiii:nN #1#2
   {
     \exp_not:N \__str_format_if_in:nNTF
       { + - \c_catcode_other_space_tl }
diff --git a/Master/texmf-dist/tex/latex/l3experimental/l3sys-shell/l3sys-shell.sty b/Master/texmf-dist/tex/latex/l3experimental/l3sys-shell/l3sys-shell.sty
index a0e5cdd5438..2fe417c0258 100644
--- a/Master/texmf-dist/tex/latex/l3experimental/l3sys-shell/l3sys-shell.sty
+++ b/Master/texmf-dist/tex/latex/l3experimental/l3sys-shell/l3sys-shell.sty
@@ -20,7 +20,7 @@
 %% 
 %% File: l3sys-shell.dtx
 \RequirePackage{expl3}
-\ProvidesExplPackage{l3sys-shell}{2023-05-11}{}
+\ProvidesExplPackage{l3sys-shell}{2023-10-10}{}
   {L3 Experimental system shell functions}
 \scan_new:N \s__sys_stop
 \quark_new:N \q__sys_nil
@@ -48,11 +48,11 @@
          \__sys_path_to_win:N
       }
   }
-\cs_new_protected:Npx \sys_shell_cp:nn #1#2
+\cs_new_protected:Npe \sys_shell_cp:nn #1#2
   {
     \sys_if_shell_unrestricted:T
       {
-        \sys_shell_now:x
+        \sys_shell_now:e
           {
             \sys_if_platform_unix:T
               {
@@ -67,11 +67,11 @@
           }
       }
   }
-\cs_new_protected:Npx \sys_shell_mkdir:n #1
+\cs_new_protected:Npe \sys_shell_mkdir:n #1
   {
     \sys_if_shell_unrestricted:T
       {
-        \sys_shell_now:x
+        \sys_shell_now:e
           {
             \sys_if_platform_unix:T
               { mkdir~-p~ \exp_not:N \tl_to_str:n {#1} }
@@ -84,11 +84,11 @@
           }
       }
   }
-\cs_new_protected:Npx \sys_shell_mv:nn #1#2
+\cs_new_protected:Npe \sys_shell_mv:nn #1#2
   {
     \sys_if_shell_unrestricted:T
       {
-        \sys_shell_now:x
+        \sys_shell_now:e
           {
             \sys_if_platform_unix:T
               {
@@ -105,11 +105,11 @@
           }
       }
   }
-\cs_new_protected:Npx \sys_shell_rm:n #1
+\cs_new_protected:Npe \sys_shell_rm:n #1
   {
     \sys_if_shell_unrestricted:T
       {
-        \sys_shell_now:x
+        \sys_shell_now:e
           {
             \sys_if_platform_unix:T
               { rm~-f~ \exp_not:N \tl_to_str:n {#1}  }
@@ -118,12 +118,12 @@
           }
       }
   }
-\cs_new_protected:Npx \sys_shell_rmdir:n #1
+\cs_new_protected:Npe \sys_shell_rmdir:n #1
   {
     \sys_if_shell_unrestricted:T
       {
         \sys_shell_mkdir:n {#1}
-        \sys_shell_now:x
+        \sys_shell_now:e
           {
             \sys_if_platform_unix:T
               { rm~-rf~ \exp_not:N \tl_to_str:n {#1} }
@@ -133,7 +133,7 @@
       }
   }
 \tl_new:N \l__sys_tmp_tl
-\cs_new_protected:Npx \sys_get_shell_pwd:N #1
+\cs_new_protected:Npe \sys_get_shell_pwd:N #1
   {
     \sys_if_shell_unrestricted:T
       {
@@ -154,7 +154,7 @@
         \str_set:NV #1 \exp_not:N \l__sys_tmp_tl
       }
   }
-\cs_new_protected:Npx \sys_shell_split_ls:nN #1#2
+\cs_new_protected:Npe \sys_shell_split_ls:nN #1#2
   {
     \sys_if_shell_unrestricted:T
       {
diff --git a/Master/texmf-dist/tex/latex/l3experimental/xcoffins/xcoffins.sty b/Master/texmf-dist/tex/latex/l3experimental/xcoffins/xcoffins.sty
index 043034a53e9..bb1f6c36925 100644
--- a/Master/texmf-dist/tex/latex/l3experimental/xcoffins/xcoffins.sty
+++ b/Master/texmf-dist/tex/latex/l3experimental/xcoffins/xcoffins.sty
@@ -19,7 +19,7 @@
 %% and all files in that bundle must be distributed together.
 %% 
 %% File: xcoffins.dtx
-\ProvidesExplPackage{xcoffins}{2023-05-11}{}
+\ProvidesExplPackage{xcoffins}{2023-10-10}{}
   {L3 Experimental design level coffins}
 \keys_define:nn { coffin }
   {
@@ -74,7 +74,7 @@
   {
     \group_begin:
       \__coffin_design_names:N #1
-    \use:x
+    \use:e
       {
         \group_end:
         \coffin_set_horizontal_pole:Nnn #1
@@ -85,7 +85,7 @@
   {
     \group_begin:
       \__coffin_design_names:N #1
-    \use:x
+    \use:e
       {
         \group_end:
         \coffin_set_vertical_pole:Nnn #1
@@ -112,7 +112,7 @@
       {
         \group_begin:
           \keys_set:nn { coffin } {#1}
-          \tl_set:Nx \l__coffin_tmp_tl
+          \tl_set:Ne \l__coffin_tmp_tl
             {
               \group_end:
               \bool_if:NTF \l__coffin_bound_box_grow_bool
diff --git a/Master/texmf-dist/tex/latex/l3experimental/xgalley/l3galley.sty b/Master/texmf-dist/tex/latex/l3experimental/xgalley/l3galley.sty
index b10edcfbe3d..96f4c731f8f 100644
--- a/Master/texmf-dist/tex/latex/l3experimental/xgalley/l3galley.sty
+++ b/Master/texmf-dist/tex/latex/l3experimental/xgalley/l3galley.sty
@@ -32,7 +32,7 @@
       }%
     \endinput
   }
-\ProvidesExplPackage{l3galley}{2023-05-11}{}
+\ProvidesExplPackage{l3galley}{2023-10-10}{}
   {L3 Experimental galley code}
 \int_new:N \l__galley_tmp_int
 \seq_new:N \g__galley_tmpa_seq
@@ -300,7 +300,7 @@
   {
      \tl_if_empty:NF #1
        {
-         \tl_gput_right:Nx \g_galley_restore_running_tl
+         \tl_gput_right:Ne \g_galley_restore_running_tl
            {
              \int_gset:Nn \exp_not:N \g_galley_penalty_int
                { \int_use:N \g_galley_penalty_int }
@@ -312,7 +312,7 @@
   {
      \tl_if_empty:NF #1
        {
-         \tl_gput_right:Nx \g_galley_restore_running_tl
+         \tl_gput_right:Ne \g_galley_restore_running_tl
            {
              \skip_gset:Nn \exp_not:N \g_galley_vspace_skip
                { \skip_use:N \g_galley_vspace_skip }
@@ -523,7 +523,7 @@
       {
         \seq_gpop_left:NNF #2 \l__galley_tmp_tl
           { \tl_set:Nn \l__galley_tmp_tl { 0pt } }
-        \seq_put_right:Nx \l__galley_tmp_seq
+        \seq_put_right:Ne \l__galley_tmp_seq
           { \dim_eval:n { ##1 + \l__galley_tmp_tl } }
       }
   }
@@ -632,10 +632,10 @@
       { \seq_put_right:NV #1 \l__galley_tmp_tl }
   }
 \cs_new_protected:Npn \galley_penalty_set_single:n #1
-  { \tl_gset:Nx \g__galley_interpar_penalty_user_tl { \int_eval:n {#1} } }
+  { \tl_gset:Ne \g__galley_interpar_penalty_user_tl { \int_eval:n {#1} } }
 \cs_new_protected:Npn \galley_penalty_add_single:n #1
   {
-    \tl_gset:Nx \g__galley_interpar_penalty_user_tl
+    \tl_gset:Ne \g__galley_interpar_penalty_user_tl
       {
         \int_eval:n
           {
@@ -646,10 +646,10 @@
       }
   }
 \cs_new_protected:Npn \galley_vspace_set_single:n #1
-  { \tl_gset:Nx \g__galley_interpar_vspace_user_tl { \skip_eval:n {#1} } }
+  { \tl_gset:Ne \g__galley_interpar_vspace_user_tl { \skip_eval:n {#1} } }
 \cs_new_protected:Npn \galley_vspace_add_single:n #1
   {
-    \tl_gset:Nx \g__galley_interpar_vspace_user_tl
+    \tl_gset:Ne \g__galley_interpar_vspace_user_tl
       {
         \skip_eval:n
           {
@@ -848,7 +848,7 @@
   { \clist_set_eq:NN #1 \l_galley_line_penalties_clist }
 \cs_new_protected:Npn \galley_save_display_club_penalties:N #1
   {
-    \clist_set:Nx #1
+    \clist_set:Ne #1
       {
         \int_step_function:nN { \tex_clubpenalties:D 0 - 1 }
           \__galley_save_display_club_penalties:n
@@ -858,7 +858,7 @@
   { \int_value:w \tex_clubpenalties:D \int_eval:n {#1} , }
 \cs_new_protected:Npn \galley_save_display_widow_penalties:N #1
   {
-    \clist_set:Nx #1
+    \clist_set:Ne #1
       {
         \int_step_function:nN { \tex_displaywidowpenalties:D 0 - 1 }
           \__galley_save_display_widow_penalties:n
@@ -871,7 +871,7 @@
   }
 \cs_new_protected:Npn \galley_save_widow_penalties:N #1
   {
-    \clist_set:Nx #1
+    \clist_set:Ne #1
       {
         \int_step_function:nN { \tex_widowpenalties:D 0 - 1 }
           \__galley_save_widow_penalties:n
diff --git a/Master/texmf-dist/tex/latex/l3experimental/xgalley/xgalley.sty b/Master/texmf-dist/tex/latex/l3experimental/xgalley/xgalley.sty
index 1ef6f04e008..74d706bff6b 100644
--- a/Master/texmf-dist/tex/latex/l3experimental/xgalley/xgalley.sty
+++ b/Master/texmf-dist/tex/latex/l3experimental/xgalley/xgalley.sty
@@ -19,7 +19,7 @@
 %% and all files in that bundle must be distributed together.
 %% 
 %% File: xgalley.dtx
-\ProvidesExplPackage{xgalley}{2023-05-11}{}
+\ProvidesExplPackage{xgalley}{2023-10-10}{}
   {L3 Experimental galley}
 \RequirePackage{xtemplate,l3galley}
 \clist_new:N \l__galley_tmpa_clist
@@ -222,7 +222,7 @@
     stretch-last-line  = \l_galley_par_stretch_last_bool
   }
   {
-    \tl_put_left:Nx \l__galley_justification_other_tl
+    \tl_put_left:Ne \l__galley_justification_other_tl
       {
         \skip_set:Nn \exp_not:N \l_galley_par_end_skip
           { \skip_use:N \l_galley_par_end_skip }
@@ -411,7 +411,7 @@
   {
     \tl_if_empty:NF \l__galley_interline_penalty_tl
       {
-        \tl_gput_right:Nx \g_galley_par_reset_hook_tl
+        \tl_gput_right:Ne \g_galley_par_reset_hook_tl
           {
             \int_set:Nn \exp_not:N \l__galley_interline_penalty_int
               { \galley_interline_penalty: }
@@ -421,7 +421,7 @@
       }
     \tl_if_empty:NF \l__galley_parbreak_fuzz_tl
       {
-        \tl_gput_right:Nx \g_galley_par_reset_hook_tl
+        \tl_gput_right:Ne \g_galley_par_reset_hook_tl
           {
             \dim_set:Nn \exp_not:N \l_galley_parbreak_fuzz_dim
               { \dim_use:N \l_galley_parbreak_fuzz_dim }
@@ -432,7 +432,7 @@
       {
         \tl_if_empty:cF { l_galley_ ##1 _tl }
           {
-            \tl_gput_right:Nx \g_galley_par_reset_hook_tl
+            \tl_gput_right:Ne \g_galley_par_reset_hook_tl
               {
                 \int_set:Nn \exp_not:c { l_galley_ ##1 _int }
                   { \int_use:c { l_galley_ ##1 _int } }
@@ -446,7 +446,7 @@
         \tl_if_empty:cF { l_galley_ ##1 _tl }
           {
             \use:c { galley_save_ ##1 :N } \l__galley_tmpa_clist
-            \tl_gput_right:Nx \g_galley_par_reset_hook_tl
+            \tl_gput_right:Ne \g_galley_par_reset_hook_tl
               {
                 \exp_not:c { galley_set_ ##1 :n }
                   { \exp_not:o \l__galley_tmpa_clist }
@@ -518,22 +518,22 @@
   {
     \tl_if_empty:NF \l_galley_display_begin_par_vpenalty_tl
       {
-        \tl_set:Nx \l_galley_display_begin_par_vpenalty_tl
+        \tl_set:Ne \l_galley_display_begin_par_vpenalty_tl
           { \int_eval:n { \l_galley_display_begin_par_vpenalty_tl } }
       }
     \tl_if_empty:NF \l_galley_display_begin_par_vspace_tl
       {
-        \tl_set:Nx \l_galley_display_begin_par_vspace_tl
+        \tl_set:Ne \l_galley_display_begin_par_vspace_tl
           { \skip_eval:n { \l_galley_display_begin_par_vspace_tl } }
       }
     \tl_if_empty:NF \l_galley_display_begin_vpenalty_tl
       {
-        \tl_set:Nx \l_galley_display_begin_vpenalty_tl
+        \tl_set:Ne \l_galley_display_begin_vpenalty_tl
           { \int_eval:n { \l_galley_display_begin_vpenalty_tl } }
       }
     \tl_if_empty:NF \l_galley_display_begin_vspace_tl
       {
-        \tl_set:Nx \l_galley_display_begin_vspace_tl
+        \tl_set:Ne \l_galley_display_begin_vspace_tl
           { \skip_eval:n { \l_galley_display_begin_vspace_tl } }
       }
   }
@@ -547,22 +547,22 @@
   {
     \tl_if_empty:NF \l_galley_display_end_par_vpenalty_tl
       {
-        \tl_set:Nx \l_galley_display_end_par_vpenalty_tl
+        \tl_set:Ne \l_galley_display_end_par_vpenalty_tl
           { \int_eval:n { \l_galley_display_end_par_vpenalty_tl } }
       }
     \tl_if_empty:NF \l_galley_display_end_par_vspace_tl
       {
-        \tl_set:Nx \l_galley_display_end_par_vspace_tl
+        \tl_set:Ne \l_galley_display_end_par_vspace_tl
           { \skip_eval:n { \l_galley_display_end_par_vspace_tl } }
       }
     \tl_if_empty:NF \l_galley_display_end_vpenalty_tl
       {
-        \tl_set:Nx \l_galley_display_end_vpenalty_tl
+        \tl_set:Ne \l_galley_display_end_vpenalty_tl
           { \int_eval:n { \l_galley_display_end_vpenalty_tl } }
       }
     \tl_if_empty:NF \l_galley_display_end_vspace_tl
       {
-        \tl_set:Nx \l_galley_display_end_vspace_tl
+        \tl_set:Ne \l_galley_display_end_vspace_tl
           { \skip_eval:n { \l_galley_display_end_vspace_tl } }
       }
   }
diff --git a/Master/texmf-dist/tex/latex/l3kernel/expl3-code.tex b/Master/texmf-dist/tex/latex/l3kernel/expl3-code.tex
index ac67d0b7f43..0b57711f157 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/expl3-code.tex
+++ b/Master/texmf-dist/tex/latex/l3kernel/expl3-code.tex
@@ -71,7 +71,7 @@
 %% and all files in that bundle must be distributed together.
 %% 
 %% File: expl3.dtx
-\def\ExplFileDate{2023-08-29}%
+\def\ExplFileDate{2023-10-10}%
 \begingroup
   \def\next{\endgroup}%
   \expandafter\ifx\csname PackageError\endcsname\relax
@@ -236,7 +236,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \bool_if:NF \l__kernel_expl_bool
       {
-        \cs_set_protected:Npx \ExplSyntaxOff
+        \cs_set_protected:Npe \ExplSyntaxOff
           {
             \char_set_catcode:nn { 9 }   { \char_value_catcode:n { 9 } }
             \char_set_catcode:nn { 32 }  { \char_value_catcode:n { 32 } }
@@ -1508,33 +1508,41 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   \tex_fi:D
 \tex_fi:D
 \tex_let:D \cs_set_nopar:Npn            \tex_def:D
+\tex_let:D \cs_set_nopar:Npe            \tex_edef:D
 \tex_let:D \cs_set_nopar:Npx            \tex_edef:D
 \tex_protected:D \tex_long:D \tex_def:D \cs_set:Npn
   { \tex_long:D \tex_def:D }
-\tex_protected:D \tex_long:D \tex_def:D \cs_set:Npx
+\tex_protected:D \tex_long:D \tex_def:D \cs_set:Npe
   { \tex_long:D \tex_edef:D }
+\tex_let:D \cs_set:Npx \cs_set:Npe
 \tex_protected:D \tex_long:D \tex_def:D \cs_set_protected_nopar:Npn
   { \tex_protected:D \tex_def:D }
-\tex_protected:D \tex_long:D \tex_def:D \cs_set_protected_nopar:Npx
+\tex_protected:D \tex_long:D \tex_def:D \cs_set_protected_nopar:Npe
   { \tex_protected:D \tex_edef:D }
+\tex_let:D \cs_set_protected_nopar:Npx \cs_set_protected_nopar:Npe
 \tex_protected:D \tex_long:D \tex_def:D \cs_set_protected:Npn
   { \tex_protected:D \tex_long:D \tex_def:D }
-\tex_protected:D \tex_long:D \tex_def:D \cs_set_protected:Npx
+\tex_protected:D \tex_long:D \tex_def:D \cs_set_protected:Npe
   { \tex_protected:D \tex_long:D \tex_edef:D }
+\tex_let:D \cs_set_protected:Npx \cs_set_protected:Npe
 \tex_let:D \cs_gset_nopar:Npn           \tex_gdef:D
+\tex_let:D \cs_gset_nopar:Npe           \tex_xdef:D
 \tex_let:D \cs_gset_nopar:Npx           \tex_xdef:D
 \cs_set_protected:Npn \cs_gset:Npn
   { \tex_long:D \tex_gdef:D }
-\cs_set_protected:Npn \cs_gset:Npx
+\cs_set_protected:Npn \cs_gset:Npe
   { \tex_long:D \tex_xdef:D }
+\tex_let:D \cs_gset:Npx \cs_gset:Npe
 \cs_set_protected:Npn \cs_gset_protected_nopar:Npn
   { \tex_protected:D \tex_gdef:D }
-\cs_set_protected:Npn \cs_gset_protected_nopar:Npx
+\cs_set_protected:Npn \cs_gset_protected_nopar:Npe
   { \tex_protected:D \tex_xdef:D }
+\tex_let:D \cs_gset_protected_nopar:Npx \cs_gset_protected_nopar:Npe
 \cs_set_protected:Npn \cs_gset_protected:Npn
   { \tex_protected:D \tex_long:D \tex_gdef:D }
-\cs_set_protected:Npn \cs_gset_protected:Npx
+\cs_set_protected:Npn \cs_gset_protected:Npe
   { \tex_protected:D \tex_long:D \tex_xdef:D }
+\tex_let:D \cs_gset_protected:Npx \cs_gset_protected:Npe
 \cs_set_nopar:Npn \l__exp_internal_tl { }
 \cs_set:Npn \use:c #1 { \cs:w #1 \cs_end: }
 \cs_set_protected:Npn \use:x #1
@@ -1649,7 +1657,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \__prg_generate_conditional_parm:NNNpnn \cs_new_protected:Npn p }
 \cs_set_protected:Npn \__prg_generate_conditional_parm:NNNpnn #1#2#3#4#
   {
-    \use:x
+    \use:e
       {
         \__prg_generate_conditional:nnNNNnnn
           \cs_split_function:N #3
@@ -1670,7 +1678,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \__prg_generate_conditional_count:NNNnn \cs_new_protected:Npn p }
 \cs_set_protected:Npn \__prg_generate_conditional_count:NNNnn #1#2#3
   {
-    \use:x
+    \use:e
       {
         \__prg_generate_conditional_count:nnNNNnn
         \cs_split_function:N #3
@@ -1683,7 +1691,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { \__prg_generate_conditional:nnNNNnnn {#1} {#2} #3 #4 #5 }
       { \tl_count:n {#2} }
       {
-        \msg_error:nnxx { kernel } { bad-number-of-arguments }
+        \msg_error:nnee { kernel } { bad-number-of-arguments }
           { \token_to_str:c { #1 : #2 } }
           { \tl_count:n {#2} }
         \use_none:nn
@@ -1692,11 +1700,11 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_set_protected:Npn \__prg_generate_conditional:nnNNNnnn #1#2#3#4#5#6#7#8
   {
     \if_meaning:w \c_false_bool #3
-      \msg_error:nnx { kernel } { missing-colon }
+      \msg_error:nne { kernel } { missing-colon }
         { \token_to_str:c {#1} }
       \exp_after:wN \use_none:nn
     \fi:
-    \use:x
+    \use:e
       {
         \exp_not:N \__prg_generate_conditional:NNnnnnNw
         \exp_not:n { #4 #5 {#1} {#2} {#6} }
@@ -1723,7 +1731,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \use:c { __prg_generate_ #8 _form:wNNnnnnN }
         \tl_if_empty:nF {#8}
           {
-            \msg_error:nnxx
+            \msg_error:nnee
               { kernel } { conditional-form-unknown }
               {#8} { \token_to_str:c { #3 : #4 } }
           }
@@ -1747,7 +1755,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           { #7 \__prg_p_true:w \fi: \c_false_bool }
       }
       {
-        \msg_error:nnx { kernel } { protected-predicate }
+        \msg_error:nne { kernel } { protected-predicate }
           { \token_to_str:c { #4 _p: #5 } }
       }
   }
@@ -1787,7 +1795,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \__prg_set_eq_conditional:NNNn \cs_new_eq:cc }
 \cs_set_protected:Npn \__prg_set_eq_conditional:NNNn #1#2#3#4
   {
-    \use:x
+    \use:e
       {
         \exp_not:N \__prg_set_eq_conditional:nnNnnNNw
           \cs_split_function:N #2
@@ -1800,12 +1808,12 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_set_protected:Npn \__prg_set_eq_conditional:nnNnnNNw #1#2#3#4#5#6
   {
     \if_meaning:w \c_false_bool #3
-      \msg_error:nnx { kernel } { missing-colon }
+      \msg_error:nne { kernel } { missing-colon }
         { \token_to_str:c {#1} }
       \exp_after:wN \__prg_use_none_delimit_by_q_recursion_stop:w
     \fi:
     \if_meaning:w \c_false_bool #6
-      \msg_error:nnx { kernel } { missing-colon }
+      \msg_error:nne { kernel } { missing-colon }
         { \token_to_str:c {#4} }
       \exp_after:wN \__prg_use_none_delimit_by_q_recursion_stop:w
     \fi:
@@ -1819,7 +1827,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \use:c { __prg_set_eq_conditional_ #6 _form:wNnnnn }
         \tl_if_empty:nF {#6}
           {
-            \msg_error:nnxx
+            \msg_error:nnee
               { kernel } { conditional-form-unknown }
               {#6} { \token_to_str:c { #1 : #2 } }
           }
@@ -1935,7 +1943,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \cs_if_exist:cTF {#1} { \use:c {#1} #2 } { } }
 \cs_set:Npn \cs_if_exist_use:c #1
   { \cs_if_exist:cTF {#1} { \use:c {#1} } { } }
-\cs_set_protected:Npn \msg_error:nnxx #1#2#3#4
+\cs_set_protected:Npn \msg_error:nnee #1#2#3#4
   {
     \tex_newlinechar:D = `\^^J \scan_stop:
     \tex_errmessage:D
@@ -1948,21 +1956,21 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
     \tex_end:D
   }
-\cs_set_protected:Npn \msg_error:nnx #1#2#3
-  { \msg_error:nnxx {#1} {#2} {#3} { } }
+\cs_set_protected:Npn \msg_error:nne #1#2#3
+  { \msg_error:nnee {#1} {#2} {#3} { } }
 \cs_set_protected:Npn \msg_error:nn #1#2
-  { \msg_error:nnxx {#1} {#2} { } { } }
+  { \msg_error:nnee {#1} {#2} { } { } }
 \cs_set:Npn \msg_line_context:
   { on~line~ \tex_the:D \tex_inputlineno:D }
-\cs_set_protected:Npn \iow_log:x
+\cs_set_protected:Npn \iow_log:e
   { \tex_immediate:D \tex_write:D -1 }
-\cs_set_protected:Npn \iow_term:x
+\cs_set_protected:Npn \iow_term:e
   { \tex_immediate:D \tex_write:D 16 }
 \cs_set_protected:Npn \__kernel_chk_if_free_cs:N #1
   {
     \cs_if_free:NF #1
       {
-        \msg_error:nnxx { kernel } { command-already-defined }
+        \msg_error:nnee { kernel } { command-already-defined }
           { \token_to_str:N #1 } { \token_to_meaning:N #1 }
       }
   }
@@ -1977,38 +1985,54 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
   }
 \__cs_tmp:w \cs_new_nopar:Npn           \cs_gset_nopar:Npn
+\__cs_tmp:w \cs_new_nopar:Npe           \cs_gset_nopar:Npe
 \__cs_tmp:w \cs_new_nopar:Npx           \cs_gset_nopar:Npx
 \__cs_tmp:w \cs_new:Npn                 \cs_gset:Npn
+\__cs_tmp:w \cs_new:Npe                 \cs_gset:Npe
 \__cs_tmp:w \cs_new:Npx                 \cs_gset:Npx
 \__cs_tmp:w \cs_new_protected_nopar:Npn \cs_gset_protected_nopar:Npn
+\__cs_tmp:w \cs_new_protected_nopar:Npe \cs_gset_protected_nopar:Npe
 \__cs_tmp:w \cs_new_protected_nopar:Npx \cs_gset_protected_nopar:Npx
 \__cs_tmp:w \cs_new_protected:Npn       \cs_gset_protected:Npn
+\__cs_tmp:w \cs_new_protected:Npe       \cs_gset_protected:Npe
 \__cs_tmp:w \cs_new_protected:Npx       \cs_gset_protected:Npx
 \cs_set:Npn \__cs_tmp:w #1#2
   { \cs_new_protected_nopar:Npn #1 { \exp_args:Nc #2 } }
 \__cs_tmp:w \cs_set_nopar:cpn  \cs_set_nopar:Npn
+\__cs_tmp:w \cs_set_nopar:cpe  \cs_set_nopar:Npe
 \__cs_tmp:w \cs_set_nopar:cpx  \cs_set_nopar:Npx
 \__cs_tmp:w \cs_gset_nopar:cpn \cs_gset_nopar:Npn
+\__cs_tmp:w \cs_gset_nopar:cpe \cs_gset_nopar:Npe
 \__cs_tmp:w \cs_gset_nopar:cpx \cs_gset_nopar:Npx
 \__cs_tmp:w \cs_new_nopar:cpn  \cs_new_nopar:Npn
+\__cs_tmp:w \cs_new_nopar:cpe  \cs_new_nopar:Npe
 \__cs_tmp:w \cs_new_nopar:cpx  \cs_new_nopar:Npx
 \__cs_tmp:w \cs_set:cpn  \cs_set:Npn
+\__cs_tmp:w \cs_set:cpe  \cs_set:Npe
 \__cs_tmp:w \cs_set:cpx  \cs_set:Npx
 \__cs_tmp:w \cs_gset:cpn \cs_gset:Npn
+\__cs_tmp:w \cs_gset:cpe \cs_gset:Npe
 \__cs_tmp:w \cs_gset:cpx \cs_gset:Npx
 \__cs_tmp:w \cs_new:cpn  \cs_new:Npn
+\__cs_tmp:w \cs_new:cpe  \cs_new:Npe
 \__cs_tmp:w \cs_new:cpx  \cs_new:Npx
 \__cs_tmp:w \cs_set_protected_nopar:cpn  \cs_set_protected_nopar:Npn
+\__cs_tmp:w \cs_set_protected_nopar:cpe  \cs_set_protected_nopar:Npe
 \__cs_tmp:w \cs_set_protected_nopar:cpx  \cs_set_protected_nopar:Npx
 \__cs_tmp:w \cs_gset_protected_nopar:cpn \cs_gset_protected_nopar:Npn
+\__cs_tmp:w \cs_gset_protected_nopar:cpe \cs_gset_protected_nopar:Npe
 \__cs_tmp:w \cs_gset_protected_nopar:cpx \cs_gset_protected_nopar:Npx
 \__cs_tmp:w \cs_new_protected_nopar:cpn  \cs_new_protected_nopar:Npn
+\__cs_tmp:w \cs_new_protected_nopar:cpe  \cs_new_protected_nopar:Npe
 \__cs_tmp:w \cs_new_protected_nopar:cpx  \cs_new_protected_nopar:Npx
 \__cs_tmp:w \cs_set_protected:cpn  \cs_set_protected:Npn
+\__cs_tmp:w \cs_set_protected:cpe  \cs_set_protected:Npe
 \__cs_tmp:w \cs_set_protected:cpx  \cs_set_protected:Npx
 \__cs_tmp:w \cs_gset_protected:cpn \cs_gset_protected:Npn
+\__cs_tmp:w \cs_gset_protected:cpe \cs_gset_protected:Npe
 \__cs_tmp:w \cs_gset_protected:cpx \cs_gset_protected:Npx
 \__cs_tmp:w \cs_new_protected:cpn  \cs_new_protected:Npn
+\__cs_tmp:w \cs_new_protected:cpe  \cs_new_protected:Npe
 \__cs_tmp:w \cs_new_protected:cpx  \cs_new_protected:Npx
 \cs_new_protected:Npn \cs_set_eq:NN #1 { \tex_let:D #1 =~ }
 \cs_new_protected:Npn \cs_set_eq:cN { \exp_args:Nc  \cs_set_eq:NN }
@@ -2039,7 +2063,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_set_protected:Npn \__kernel_cs_parm_from_arg_count:nnF #1#2
   {
-    \exp_args:Nx \__cs_parm_from_arg_count_test:nnF
+    \exp_args:Ne \__cs_parm_from_arg_count_test:nnF
       {
         \exp_after:wN \exp_not:n
         \if_case:w \int_eval:n {#2}
@@ -2085,7 +2109,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \__kernel_cs_parm_from_arg_count:nnF { \use:nnn #2 #1 } {#3}
       {
-        \msg_error:nnxx { kernel } { bad-number-of-arguments }
+        \msg_error:nnee { kernel } { bad-number-of-arguments }
           { \token_to_str:N #1 } { \int_eval:n {#3} }
         \use_none:n
       }
@@ -2105,7 +2129,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__cs_generate_from_signature:NNn #1#2
   {
-    \use:x
+    \use:e
       {
         \__cs_generate_from_signature:nnNNNn
         \cs_split_function:N #2
@@ -2120,14 +2144,14 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           { \tl_map_function:nN {#2} \__cs_generate_from_signature:n }
         \tl_if_empty:oF \__cs_tmp:w
           {
-            \msg_error:nnxxx { kernel } { non-base-function }
+            \msg_error:nneee { kernel } { non-base-function }
               { \token_to_str:N #5 } {#2} { \__cs_tmp:w }
           }
         \cs_generate_from_arg_count:NNnn
           #5 #4 { \tl_count:n {#2} } {#6}
       }
       {
-        \msg_error:nnx { kernel } { missing-colon }
+        \msg_error:nne { kernel } { missing-colon }
           { \token_to_str:N #5 }
       }
   }
@@ -2137,28 +2161,40 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \if:w T #1 \else: \if:w F #1 \else: #1 \fi: \fi: \fi: \fi:
   }
 \__cs_tmp:w { set }                  { Nn } { Npn }
+\__cs_tmp:w { set }                  { Ne } { Npe }
 \__cs_tmp:w { set }                  { Nx } { Npx }
 \__cs_tmp:w { set_nopar }            { Nn } { Npn }
+\__cs_tmp:w { set_nopar }            { Ne } { Npe }
 \__cs_tmp:w { set_nopar }            { Nx } { Npx }
 \__cs_tmp:w { set_protected }        { Nn } { Npn }
+\__cs_tmp:w { set_protected }        { Ne } { Npe }
 \__cs_tmp:w { set_protected }        { Nx } { Npx }
 \__cs_tmp:w { set_protected_nopar }  { Nn } { Npn }
+\__cs_tmp:w { set_protected_nopar }  { Ne } { Npe }
 \__cs_tmp:w { set_protected_nopar }  { Nx } { Npx }
 \__cs_tmp:w { gset }                 { Nn } { Npn }
+\__cs_tmp:w { gset }                 { Ne } { Npe }
 \__cs_tmp:w { gset }                 { Nx } { Npx }
 \__cs_tmp:w { gset_nopar }           { Nn } { Npn }
+\__cs_tmp:w { gset_nopar }           { Ne } { Npe }
 \__cs_tmp:w { gset_nopar }           { Nx } { Npx }
 \__cs_tmp:w { gset_protected }       { Nn } { Npn }
+\__cs_tmp:w { gset_protected }       { Ne } { Npe }
 \__cs_tmp:w { gset_protected }       { Nx } { Npx }
 \__cs_tmp:w { gset_protected_nopar } { Nn } { Npn }
+\__cs_tmp:w { gset_protected_nopar } { Ne } { Npe }
 \__cs_tmp:w { gset_protected_nopar } { Nx } { Npx }
 \__cs_tmp:w { new }                  { Nn } { Npn }
+\__cs_tmp:w { new }                  { Ne } { Npe }
 \__cs_tmp:w { new }                  { Nx } { Npx }
 \__cs_tmp:w { new_nopar }            { Nn } { Npn }
+\__cs_tmp:w { new_nopar }            { Ne } { Npe }
 \__cs_tmp:w { new_nopar }            { Nx } { Npx }
 \__cs_tmp:w { new_protected }        { Nn } { Npn }
+\__cs_tmp:w { new_protected }        { Ne } { Npe }
 \__cs_tmp:w { new_protected }        { Nx } { Npx }
 \__cs_tmp:w { new_protected_nopar }  { Nn } { Npn }
+\__cs_tmp:w { new_protected_nopar }  { Ne } { Npe }
 \__cs_tmp:w { new_protected_nopar }  { Nx } { Npx }
 \cs_set:Npn \__cs_tmp:w #1#2
   {
@@ -2169,28 +2205,40 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
   }
 \__cs_tmp:w { set }                  { n }
+\__cs_tmp:w { set }                  { e }
 \__cs_tmp:w { set }                  { x }
 \__cs_tmp:w { set_nopar }            { n }
+\__cs_tmp:w { set_nopar }            { e }
 \__cs_tmp:w { set_nopar }            { x }
 \__cs_tmp:w { set_protected }        { n }
+\__cs_tmp:w { set_protected }        { e }
 \__cs_tmp:w { set_protected }        { x }
 \__cs_tmp:w { set_protected_nopar }  { n }
+\__cs_tmp:w { set_protected_nopar }  { e }
 \__cs_tmp:w { set_protected_nopar }  { x }
 \__cs_tmp:w { gset }                 { n }
+\__cs_tmp:w { gset }                 { e }
 \__cs_tmp:w { gset }                 { x }
 \__cs_tmp:w { gset_nopar }           { n }
+\__cs_tmp:w { gset_nopar }           { e }
 \__cs_tmp:w { gset_nopar }           { x }
 \__cs_tmp:w { gset_protected }       { n }
+\__cs_tmp:w { gset_protected }       { e }
 \__cs_tmp:w { gset_protected }       { x }
 \__cs_tmp:w { gset_protected_nopar } { n }
+\__cs_tmp:w { gset_protected_nopar } { e }
 \__cs_tmp:w { gset_protected_nopar } { x }
 \__cs_tmp:w { new }                  { n }
+\__cs_tmp:w { new }                  { e }
 \__cs_tmp:w { new }                  { x }
 \__cs_tmp:w { new_nopar }            { n }
+\__cs_tmp:w { new_nopar }            { e }
 \__cs_tmp:w { new_nopar }            { x }
 \__cs_tmp:w { new_protected }        { n }
+\__cs_tmp:w { new_protected }        { e }
 \__cs_tmp:w { new_protected }        { x }
 \__cs_tmp:w { new_protected_nopar }  { n }
+\__cs_tmp:w { new_protected_nopar }  { e }
 \__cs_tmp:w { new_protected_nopar }  { x }
 \prg_new_conditional:Npnn \cs_if_eq:NN #1#2 { p , T , F , TF }
   {
@@ -2214,7 +2262,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \cs_if_exist:NTF #1
       {#2}
       {
-        \msg_error:nnx { kernel } { variable-not-defined }
+        \msg_error:nne { kernel } { variable-not-defined }
           { \token_to_str:N #1 }
       }
   }
@@ -2246,7 +2294,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \group_begin:
       \int_set:Nn \tex_escapechar:D { `\\ }
-      \exp_args:NNx
+      \exp_args:NNe
     \group_end:
     #1 { \token_to_str:N #2 = \cs_meaning:N #2 }
   }
@@ -2256,7 +2304,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \__kernel_group_show:NN \int_zero:N 0 }
 \cs_new_protected:Npn \__kernel_group_show:NN #1#2
   {
-    \use:x
+    \use:e
       {
         #1 \tex_interactionmode:D
         \int_set:Nn \tex_tracingonline:D  {#2}
@@ -2271,7 +2319,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           { \int_use:N \tex_errorcontextlines:D }
       }
   }
-\use:x
+\use:e
   {
     \exp_not:n { \cs_new:Npn \__kernel_prefix_arg_replacement:wN #1 }
     \tl_to_str:n { macro : } \exp_not:n { #2 -> #3 \s__kernel_stop #4 }
@@ -2345,7 +2393,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \use:nn { \cs_new_eq:NN \exp_stop_f: } { ~ }
 \cs_new_protected:Npn \::x #1 \::: #2#3
   {
-    \cs_set_nopar:Npx \l__exp_internal_tl
+    \cs_set_nopar:Npe \l__exp_internal_tl
       { \exp_not:n { #1 \::: } { \exp_not:n {#2} {#3} } }
     \l__exp_internal_tl
   }
@@ -2480,6 +2528,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \exp_after:wN #3
     \exp_after:wN { \exp:w \__exp_eval_register:c {#4} }
   }
+\cs_new:Npn \exp_args:NNNe #1#2#3#4
+  {
+    \exp_after:wN #1
+    \exp_after:wN #2
+    \exp_after:wN #3
+    \tex_expanded:D { {#4} }
+  }
 \cs_new:Npn \exp_args:NcNc #1#2#3#4
   {
     \exp_after:wN #1
@@ -2525,7 +2580,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \::x_unbraced \::: #1#2
   {
-    \cs_set_nopar:Npx \l__exp_internal_tl { \exp_not:n {#1} #2 }
+    \cs_set_nopar:Npe \l__exp_internal_tl { \exp_not:n {#1} #2 }
     \l__exp_internal_tl
   }
 \cs_new:Npn \exp_last_unbraced:No #1#2 { \exp_after:wN #1 #2 }
@@ -2631,7 +2686,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \cs_generate_variant:Nn #1#2
   {
     \__cs_generate_variant:N #1
-    \use:x
+    \use:e
       {
         \__cs_generate_variant:nnNN
           \cs_split_function:N #1
@@ -2643,18 +2698,18 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \cs_generate_variant:cn
   { \exp_args:Nc \cs_generate_variant:Nn }
-\cs_new_protected:Npx \__cs_generate_variant:N #1
+\cs_new_protected:Npe \__cs_generate_variant:N #1
   {
     \exp_not:N \exp_after:wN \exp_not:N \if_meaning:w
       \exp_not:N \exp_not:N #1 #1
-      \cs_set_eq:NN \exp_not:N \__cs_tmp:w \cs_new_protected:Npx
+      \cs_set_eq:NN \exp_not:N \__cs_tmp:w \cs_new_protected:Npe
     \exp_not:N \else:
       \exp_not:N \exp_after:wN \exp_not:N \__cs_generate_variant:ww
         \exp_not:N \token_to_meaning:N #1 \tl_to_str:n { ma }
           \s__cs_mark
-        \s__cs_mark \cs_new_protected:Npx
+        \s__cs_mark \cs_new_protected:Npe
         \tl_to_str:n { pr }
-        \s__cs_mark \cs_new:Npx
+        \s__cs_mark \cs_new:Npe
         \s__cs_stop
     \exp_not:N \fi:
   }
@@ -2669,7 +2724,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__cs_generate_variant:nnNN #1#2#3#4
   {
     \if_meaning:w \c_false_bool #3
-      \msg_error:nnx { kernel } { missing-colon }
+      \msg_error:nne { kernel } { missing-colon }
         { \token_to_str:c {#1} }
       \exp_after:wN \__cs_use_none_delimit_by_q_recursion_stop:w
     \fi:
@@ -2680,7 +2735,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \if_meaning:w \scan_stop: #4
       \exp_after:wN \__cs_use_none_delimit_by_q_recursion_stop:w
     \fi:
-    \use:x
+    \use:e
       {
         \exp_not:N \__cs_generate_variant:wwNN
         \__cs_generate_variant_loop:nNwN { }
@@ -2754,7 +2809,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \exp_not:n
       {
         \s__cs_mark
-        \msg_error:nnxx { kernel } { variant-too-long }
+        \msg_error:nnee { kernel } { variant-too-long }
           {#5} { \token_to_str:N #3 }
         \use_none:nnn
         \s__cs_stop
@@ -2769,7 +2824,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \exp_not:n
       {
         \s__cs_mark
-        \msg_error:nnxxxx { kernel } { invalid-variant }
+        \msg_error:nneeee { kernel } { invalid-variant }
           {#7} { \token_to_str:N #5 } {#1} {#2}
         \use_none:nnn
         \s__cs_stop
@@ -2783,7 +2838,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     #3 \s__cs_stop #4 #5 {#6} {#7}
     \exp_not:n
       {
-        \msg_error:nnxxxx
+        \msg_error:nneeee
           { kernel } { deprecated-variant }
           {#7} { \token_to_str:N #5 } {#1} {#2}
       }
@@ -2811,11 +2866,11 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \group_end:
       }
   }
-\cs_new_protected:Npx \__cs_generate_internal_variant:n #1
+\cs_new_protected:Npe \__cs_generate_internal_variant:n #1
   {
     \exp_not:N \__cs_generate_internal_variant:wwnNwn
       #1 \s__cs_mark
-        { \cs_set_eq:NN \exp_not:N \__cs_tmp:w \cs_new_protected:Npx }
+        { \cs_set_eq:NN \exp_not:N \__cs_tmp:w \cs_new_protected:Npe }
         \cs_new_protected:cpn
         \use:x
       \token_to_str:N x \s__cs_mark
@@ -2848,7 +2903,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         ##3
         \s__cs_mark
         {
-          \use:x
+          \use:e
             {
               ##1 { exp_args:N ##3 }
                 { \__cs_generate_internal_variant_loop:n ##3 { : \use_i:nn } }
@@ -2920,7 +2975,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \prg_generate_conditional_variant:Nnn #1
   {
-    \use:x
+    \use:e
       {
         \__cs_generate_variant:nnNnn
           \cs_split_function:N #1
@@ -2929,7 +2984,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__cs_generate_variant:nnNnn #1#2#3#4#5
   {
     \if_meaning:w \c_false_bool #3
-      \msg_error:nnx { kernel } { missing-colon }
+      \msg_error:nne { kernel } { missing-colon }
         { \token_to_str:c {#1} }
       \__cs_use_i_delimit_by_s_stop:nw
     \fi:
@@ -2949,7 +3004,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \cs_if_exist_use:cTF { __cs_generate_variant_#1_form:nnn }
         { {#3} {#4} {#5} }
         {
-          \msg_error:nnxx
+          \msg_error:nnee
             { kernel } { conditional-form-unknown }
             {#1} { \token_to_str:c { #3 : #4 } }
         }
@@ -3137,18 +3192,18 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \__kernel_tl_to_str:w \exp_after:wN {#1} \q_nil
   }
 \cs_new_protected:Npn \__kernel_quark_new_test:N #1
-  { \__quark_new_test_aux:Nx #1 { \__quark_module_name:N #1 } }
+  { \__quark_new_test_aux:Ne #1 { \__quark_module_name:N #1 } }
 \cs_new_protected:Npn \__quark_new_test_aux:Nn #1 #2
   {
     \if_meaning:w \q_nil #2 \q_nil
-      \msg_error:nnx { quark } { invalid-function }
+      \msg_error:nne { quark } { invalid-function }
         { \token_to_str:N #1 }
     \else:
       \__quark_new_test:Nccn #1
         { q__#2_recursion_tail } { q__#2_recursion_stop } { __#2 }
     \fi:
   }
-\cs_generate_variant:Nn \__quark_new_test_aux:Nn { Nx }
+\cs_generate_variant:Nn \__quark_new_test_aux:Nn { Ne }
 \cs_new_protected:Npn \__quark_new_test:NNNn #1
   {
     \exp_last_unbraced:Nf \__quark_new_test_aux:nnNNnnnn
@@ -3158,18 +3213,18 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_generate_variant:Nn \__quark_new_test:NNNn { Ncc }
 \cs_new_protected:Npn \__kernel_quark_new_conditional:Nn #1
   {
-    \__quark_new_conditional:Nxxn #1
+    \__quark_new_conditional:Neen #1
       { \__quark_quark_conditional_name:N #1 }
       { \__quark_module_name:N #1 }
   }
 \cs_new_protected:Npn \__quark_new_conditional:Nnnn #1#2#3#4
   {
     \if_meaning:w \q_nil #2 \q_nil
-      \msg_error:nnx { quark } { invalid-function }
+      \msg_error:nne { quark } { invalid-function }
         { \token_to_str:N #1 }
     \else:
       \if_meaning:w \q_nil #3 \q_nil
-        \msg_error:nnx { quark } { invalid-function }
+        \msg_error:nne { quark } { invalid-function }
           { \token_to_str:N #1 }
       \else:
         \exp_last_unbraced:Nf \__quark_new_test_aux:nnNNnnnn
@@ -3179,12 +3234,12 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \fi:
     \fi:
   }
-\cs_generate_variant:Nn \__quark_new_conditional:Nnnn { Nxx }
+\cs_generate_variant:Nn \__quark_new_conditional:Nnnn { Nee }
 \cs_new_protected:Npn \__quark_new_test_aux:nnNNnnnn #1 #2 #3 #4 #5
   {
     \cs_if_exist_use:cTF { __quark_new_#5_#2:Nnnn } { #4 }
       {
-        \msg_error:nnxx { quark } { invalid-function }
+        \msg_error:nnee { quark } { invalid-function }
           { \token_to_str:N #4 } {#2}
         \use_none:nnn
       }
@@ -3312,7 +3367,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \tl_if_in:NnTF \g__scan_marks_tl { #1 }
       {
-        \msg_error:nnx { scanmark } { already-defined }
+        \msg_error:nne { scanmark } { already-defined }
           { \token_to_str:N #1 }
       }
       {
@@ -3330,8 +3385,8 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new:Npn \use_none_delimit_by_s_stop:w #1 \s_stop { }
 %% File: l3tl.dtx
-\cs_new_eq:NN \__kernel_tl_set:Nx  \cs_set_nopar:Npx
-\cs_new_eq:NN \__kernel_tl_gset:Nx \cs_gset_nopar:Npx
+\cs_new_eq:NN \__kernel_tl_set:Ne  \cs_set_nopar:Npe
+\cs_new_eq:NN \__kernel_tl_gset:Ne \cs_gset_nopar:Npe
 \cs_new_protected:Npn \tl_new:N #1
   {
     \__kernel_chk_if_free_cs:N #1
@@ -3341,15 +3396,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \tl_const:Nn #1#2
   {
     \__kernel_chk_if_free_cs:N #1
-    \cs_gset_nopar:Npx #1 { \__kernel_exp_not:w {#2} }
-  }
-\cs_new_protected:Npn \tl_const:Nx #1#2
-  {
-    \__kernel_chk_if_free_cs:N #1
-    \cs_gset_nopar:Npx #1 {#2}
+    \cs_gset_nopar:Npe #1 { \__kernel_exp_not:w {#2} }
   }
-\cs_generate_variant:Nn \tl_const:Nn { c }
-\cs_generate_variant:Nn \tl_const:Nx { c }
+\cs_generate_variant:Nn \tl_const:Nn { Ne , c , ce }
+\cs_generate_variant:Nn \tl_const:Nn { Nx , cx }
 \cs_new_protected:Npn \tl_clear:N  #1
   { \tex_let:D #1 = ~ \c_empty_tl }
 \cs_new_protected:Npn \tl_gclear:N #1
@@ -3370,7 +3420,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_generate_variant:Nn \tl_gset_eq:NN { cN, Nc, cc }
 \cs_new_protected:Npn \tl_concat:NNN #1#2#3
   {
-    \__kernel_tl_set:Nx #1
+    \__kernel_tl_set:Ne #1
       {
         \__kernel_exp_not:w \exp_after:wN {#2}
         \__kernel_exp_not:w \exp_after:wN {#3}
@@ -3378,7 +3428,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \tl_gconcat:NNN #1#2#3
   {
-    \__kernel_tl_gset:Nx #1
+    \__kernel_tl_gset:Ne #1
       {
         \__kernel_exp_not:w \exp_after:wN {#2}
         \__kernel_exp_not:w \exp_after:wN {#3}
@@ -3391,143 +3441,167 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \tl_const:Nn \c_empty_tl { }
 \group_begin:
 \tex_catcode:D `- = 11 ~
-\tl_const:Nx \c_novalue_tl { - NoValue \token_to_str:N - }
+\tl_const:Ne \c_novalue_tl { - NoValue \token_to_str:N - }
 \group_end:
 \tl_const:Nn \c_space_tl { ~ }
 \cs_new_protected:Npn \tl_set:Nn #1#2
-  { \__kernel_tl_set:Nx #1 { \__kernel_exp_not:w {#2} } }
+  { \__kernel_tl_set:Ne #1 { \__kernel_exp_not:w {#2} } }
 \cs_new_protected:Npn \tl_set:No #1#2
-  { \__kernel_tl_set:Nx #1 { \__kernel_exp_not:w \exp_after:wN {#2} } }
-\cs_new_protected:Npn \tl_set:Nx #1#2
-  { \__kernel_tl_set:Nx #1 {#2} }
+  { \__kernel_tl_set:Ne #1 { \__kernel_exp_not:w \exp_after:wN {#2} } }
 \cs_new_protected:Npn \tl_gset:Nn #1#2
-  { \__kernel_tl_gset:Nx #1 { \__kernel_exp_not:w {#2} } }
+  { \__kernel_tl_gset:Ne #1 { \__kernel_exp_not:w {#2} } }
 \cs_new_protected:Npn \tl_gset:No #1#2
-  { \__kernel_tl_gset:Nx #1 { \__kernel_exp_not:w \exp_after:wN {#2} } }
-\cs_new_protected:Npn \tl_gset:Nx #1#2
-  { \__kernel_tl_gset:Nx #1 {#2} }
+  { \__kernel_tl_gset:Ne #1 { \__kernel_exp_not:w \exp_after:wN {#2} } }
 \cs_generate_variant:Nn \tl_set:Nn  {    NV , Nv , Ne , Nf }
 \cs_generate_variant:Nn \tl_set:Nn  { c, cV , cv , ce , cf }
-\cs_generate_variant:Nn \tl_set:Nx  { c }
 \cs_generate_variant:Nn \tl_set:No  { c }
+\cs_generate_variant:Nn \tl_set:Nn  { Nx , cx }
 \cs_generate_variant:Nn \tl_gset:Nn {    NV , Nv , Ne , Nf }
 \cs_generate_variant:Nn \tl_gset:Nn { c, cV , cv , ce , cf }
-\cs_generate_variant:Nn \tl_gset:Nx { c }
 \cs_generate_variant:Nn \tl_gset:No { c }
+\cs_generate_variant:Nn \tl_gset:Nn { Nx , cx }
 \cs_new_protected:Npn \tl_put_left:Nn #1#2
   {
-    \__kernel_tl_set:Nx #1
+    \__kernel_tl_set:Ne #1
       { \__kernel_exp_not:w {#2} \__kernel_exp_not:w \exp_after:wN {#1} }
   }
 \cs_new_protected:Npn \tl_put_left:NV #1#2
   {
-    \__kernel_tl_set:Nx #1
+    \__kernel_tl_set:Ne #1
       { \exp_not:V #2 \__kernel_exp_not:w \exp_after:wN {#1} }
   }
 \cs_new_protected:Npn \tl_put_left:Nv #1#2
   {
-    \__kernel_tl_set:Nx #1
+    \__kernel_tl_set:Ne #1
       { \exp_not:v {#2} \__kernel_exp_not:w \exp_after:wN {#1} }
   }
+\cs_new_protected:Npn \tl_put_left:Ne #1#2
+  {
+    \__kernel_tl_set:Ne #1
+      {
+        \__kernel_exp_not:w \tex_expanded:D { {#2} }
+        \__kernel_exp_not:w \exp_after:wN {#1}
+      }
+  }
 \cs_new_protected:Npn \tl_put_left:No #1#2
   {
-    \__kernel_tl_set:Nx #1
+    \__kernel_tl_set:Ne #1
       {
         \__kernel_exp_not:w \exp_after:wN {#2}
         \__kernel_exp_not:w \exp_after:wN {#1}
       }
   }
-\cs_new_protected:Npn \tl_put_left:Nx #1#2
-  { \__kernel_tl_set:Nx #1 { #2 \__kernel_exp_not:w \exp_after:wN {#1} } }
 \cs_new_protected:Npn \tl_gput_left:Nn #1#2
   {
-    \__kernel_tl_gset:Nx #1
+    \__kernel_tl_gset:Ne #1
       { \__kernel_exp_not:w {#2} \__kernel_exp_not:w \exp_after:wN {#1} }
   }
 \cs_new_protected:Npn \tl_gput_left:NV #1#2
   {
-    \__kernel_tl_gset:Nx #1
+    \__kernel_tl_gset:Ne #1
       { \exp_not:V #2 \__kernel_exp_not:w \exp_after:wN {#1} }
   }
 \cs_new_protected:Npn \tl_gput_left:Nv #1#2
   {
-    \__kernel_tl_gset:Nx #1
+    \__kernel_tl_gset:Ne #1
       { \exp_not:v {#2} \__kernel_exp_not:w \exp_after:wN {#1} }
   }
+\cs_new_protected:Npn \tl_gput_left:Ne #1#2
+  {
+    \__kernel_tl_gset:Ne #1
+      {
+        \__kernel_exp_not:w \tex_expanded:D { {#2} }
+        \__kernel_exp_not:w \exp_after:wN {#1}
+      }
+  }
 \cs_new_protected:Npn \tl_gput_left:No #1#2
   {
-    \__kernel_tl_gset:Nx #1
+    \__kernel_tl_gset:Ne #1
       {
         \__kernel_exp_not:w \exp_after:wN {#2}
         \__kernel_exp_not:w \exp_after:wN {#1}
       }
   }
-\cs_new_protected:Npn \tl_gput_left:Nx #1#2
-  { \__kernel_tl_gset:Nx #1 { #2 \__kernel_exp_not:w \exp_after:wN {#1} } }
 \cs_generate_variant:Nn \tl_put_left:Nn  { c }
 \cs_generate_variant:Nn \tl_put_left:NV  { c }
 \cs_generate_variant:Nn \tl_put_left:Nv  { c }
+\cs_generate_variant:Nn \tl_put_left:Ne  { c }
 \cs_generate_variant:Nn \tl_put_left:No  { c }
-\cs_generate_variant:Nn \tl_put_left:Nx  { c }
+\cs_generate_variant:Nn \tl_put_left:Nn  { Nx, cx }
 \cs_generate_variant:Nn \tl_gput_left:Nn { c }
 \cs_generate_variant:Nn \tl_gput_left:NV { c }
-\cs_generate_variant:Nn \tl_gput_left:NV { c }
+\cs_generate_variant:Nn \tl_gput_left:Nv { c }
+\cs_generate_variant:Nn \tl_gput_left:Ne { c }
 \cs_generate_variant:Nn \tl_gput_left:No { c }
-\cs_generate_variant:Nn \tl_gput_left:Nx { c }
+\cs_generate_variant:Nn \tl_gput_left:Nn { Nx , cx }
 \cs_new_protected:Npn \tl_put_right:Nn #1#2
-  { \__kernel_tl_set:Nx #1 { \__kernel_exp_not:w \exp_after:wN { #1 #2 } } }
+  { \__kernel_tl_set:Ne #1 { \__kernel_exp_not:w \exp_after:wN { #1 #2 } } }
 \cs_new_protected:Npn \tl_put_right:NV #1#2
   {
-    \__kernel_tl_set:Nx #1
+    \__kernel_tl_set:Ne #1
       { \__kernel_exp_not:w \exp_after:wN {#1} \exp_not:V #2 }
   }
 \cs_new_protected:Npn \tl_put_right:Nv #1#2
   {
-    \__kernel_tl_set:Nx #1
+    \__kernel_tl_set:Ne #1
       { \__kernel_exp_not:w \exp_after:wN {#1} \exp_not:v {#2} }
   }
+\cs_new_protected:Npn \tl_put_right:Ne #1#2
+  {
+    \__kernel_tl_set:Ne #1
+      {
+        \__kernel_exp_not:w \exp_after:wN {#1}
+        \__kernel_exp_not:w \tex_expanded:D { {#2} }
+      }
+  }
 \cs_new_protected:Npn \tl_put_right:No #1#2
   {
-    \__kernel_tl_set:Nx #1
+    \__kernel_tl_set:Ne #1
       {
         \__kernel_exp_not:w \exp_after:wN {#1}
         \__kernel_exp_not:w \exp_after:wN {#2}
       }
   }
-\cs_new_protected:Npn \tl_put_right:Nx #1#2
-  { \__kernel_tl_set:Nx #1 { \__kernel_exp_not:w \exp_after:wN {#1} #2 } }
 \cs_new_protected:Npn \tl_gput_right:Nn #1#2
-  { \__kernel_tl_gset:Nx #1 { \__kernel_exp_not:w \exp_after:wN { #1 #2 } } }
+  { \__kernel_tl_gset:Ne #1 { \__kernel_exp_not:w \exp_after:wN { #1 #2 } } }
 \cs_new_protected:Npn \tl_gput_right:NV #1#2
   {
-    \__kernel_tl_gset:Nx #1
+    \__kernel_tl_gset:Ne #1
       { \__kernel_exp_not:w \exp_after:wN {#1} \exp_not:V #2 }
   }
 \cs_new_protected:Npn \tl_gput_right:Nv #1#2
   {
-    \__kernel_tl_gset:Nx #1
+    \__kernel_tl_gset:Ne #1
       { \__kernel_exp_not:w \exp_after:wN {#1} \exp_not:v {#2} }
   }
+\cs_new_protected:Npn \tl_gput_right:Ne #1#2
+  {
+    \__kernel_tl_gset:Ne #1
+      {
+        \__kernel_exp_not:w \exp_after:wN {#1}
+        \__kernel_exp_not:w \tex_expanded:D { {#2} }
+      }
+  }
 \cs_new_protected:Npn \tl_gput_right:No #1#2
   {
-    \__kernel_tl_gset:Nx #1
+    \__kernel_tl_gset:Ne #1
       {
         \__kernel_exp_not:w \exp_after:wN {#1}
         \__kernel_exp_not:w \exp_after:wN {#2}
       }
   }
-\cs_new_protected:Npn \tl_gput_right:Nx #1#2
-  { \__kernel_tl_gset:Nx #1 { \__kernel_exp_not:w \exp_after:wN {#1} #2 } }
 \cs_generate_variant:Nn \tl_put_right:Nn  { c }
 \cs_generate_variant:Nn \tl_put_right:NV  { c }
 \cs_generate_variant:Nn \tl_put_right:Nv  { c }
+\cs_generate_variant:Nn \tl_put_right:Ne  { c }
 \cs_generate_variant:Nn \tl_put_right:No  { c }
-\cs_generate_variant:Nn \tl_put_right:Nx  { c }
+\cs_generate_variant:Nn \tl_put_right:Nn  { Nx , cx }
 \cs_generate_variant:Nn \tl_gput_right:Nn { c }
 \cs_generate_variant:Nn \tl_gput_right:NV { c }
 \cs_generate_variant:Nn \tl_gput_right:Nv { c }
+\cs_generate_variant:Nn \tl_gput_right:Ne { c }
 \cs_generate_variant:Nn \tl_gput_right:No { c }
-\cs_generate_variant:Nn \tl_gput_right:Nx { c }
+\cs_generate_variant:Nn \tl_gput_right:Nn { Nx, cx }
 \quark_new:N \q__tl_nil
 \quark_new:N \q__tl_mark
 \quark_new:N \q__tl_stop
@@ -3535,7 +3609,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \quark_new:N \q__tl_recursion_stop
 \__kernel_quark_new_test:N \__tl_if_recursion_tail_break:nN
 \__kernel_quark_new_conditional:Nn \__tl_quark_if_nil:n { TF }
-\tl_const:Nx \c__tl_rescan_marker_tl { : \token_to_str:N : }
+\tl_const:Ne \c__tl_rescan_marker_tl { : \token_to_str:N : }
 \cs_new_protected:Npn \tl_rescan:nn #1#2
   {
     \tl_set_rescan:Nnn \l__tl_internal_a_tl {#1} {#2}
@@ -3576,10 +3650,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \group_end:
     #1 #2 {#3}
   }
-\cs_generate_variant:Nn \tl_set_rescan:Nnn  {     NnV , Nno , Nnx }
-\cs_generate_variant:Nn \tl_set_rescan:Nnn  { c , cnV , cno , cnx }
-\cs_generate_variant:Nn \tl_gset_rescan:Nnn {     NnV , Nno , Nnx }
-\cs_generate_variant:Nn \tl_gset_rescan:Nnn { c , cnV , cno , cnx }
+\cs_generate_variant:Nn \tl_set_rescan:Nnn  { NnV , Nne , c , cnV , cne }
+\cs_generate_variant:Nn \tl_set_rescan:Nnn  { Nno , Nnx , cno , cnx }
+\cs_generate_variant:Nn \tl_gset_rescan:Nnn { NnV , Nne , c , cnV , cne }
+\cs_generate_variant:Nn \tl_gset_rescan:Nnn { Nno , Nnx , cno , cnx }
 \cs_new_protected:Npn \__tl_set_rescan:nNN #1
   {
     \int_compare:nNnTF \tex_newlinechar:D < 0
@@ -3636,26 +3710,34 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   \c__tl_rescan_marker_tl #2
   { \use_i:nn \exp_end: #1 }
 \cs_new_protected:Npn \tl_replace_once:Nnn
-  { \__tl_replace:NnNNNnn \q__tl_mark ? \__tl_replace_wrap:w \__kernel_tl_set:Nx  }
+  { \__tl_replace:NnNNNnn \q__tl_mark ? \__tl_replace_wrap:w \__kernel_tl_set:Ne  }
 \cs_new_protected:Npn \tl_greplace_once:Nnn
-  { \__tl_replace:NnNNNnn \q__tl_mark ? \__tl_replace_wrap:w \__kernel_tl_gset:Nx }
+  { \__tl_replace:NnNNNnn \q__tl_mark ? \__tl_replace_wrap:w \__kernel_tl_gset:Ne }
 \cs_new_protected:Npn \tl_replace_all:Nnn
-  { \__tl_replace:NnNNNnn \q__tl_mark ? \__tl_replace_next:w \__kernel_tl_set:Nx  }
+  { \__tl_replace:NnNNNnn \q__tl_mark ? \__tl_replace_next:w \__kernel_tl_set:Ne  }
 \cs_new_protected:Npn \tl_greplace_all:Nnn
-  { \__tl_replace:NnNNNnn \q__tl_mark ? \__tl_replace_next:w \__kernel_tl_gset:Nx }
+  { \__tl_replace:NnNNNnn \q__tl_mark ? \__tl_replace_next:w \__kernel_tl_gset:Ne }
+\cs_generate_variant:Nn \tl_replace_once:Nnn
+  { NnV , Nne , NV , Ne , Nee , c , cnV , cne , cV , ce , cee }
 \cs_generate_variant:Nn \tl_replace_once:Nnn
-  { NV , NnV , Nx , Nnx , Nxx , c , cV , cnV , cx , cnx , cxx }
+  { Nx , Nnx , Nxx , cxn , cnx , cxx }
 \cs_generate_variant:Nn \tl_greplace_once:Nnn
-  { NV , NnV , Nx , Nnx , Nxx , c , cV , cnV , cx , cnx , cxx }
+  { NnV , Nne , NV , Ne , Nee , c , cnV , cne , cV , ce , cee }
+\cs_generate_variant:Nn \tl_greplace_once:Nnn
+  { Nx , Nnx , Nxx , cxn , cnx , cxx }
+\cs_generate_variant:Nn \tl_replace_all:Nnn
+  { NnV , Nne , NV , Ne , Nee , c , cnV , cne , cV , ce , cee }
 \cs_generate_variant:Nn \tl_replace_all:Nnn
-  { NV , NnV , Nx , Nnx , Nxx , c , cV , cnV , cx , cnx , cxx }
+  { Nx , Nnx , Nxx , cxn , cnx , cxx }
 \cs_generate_variant:Nn \tl_greplace_all:Nnn
-  { NV , NnV , Nx , Nnx , Nxx , c , cV , cnV , cx , cnx , cxx }
+  { NnV , Nne , NV , Ne , Nee , c , cnV , cne , cV , ce , cee }
+\cs_generate_variant:Nn \tl_greplace_all:Nnn
+  { Nx , Nnx , Nxx , cxn , cnx , cxx }
 \cs_new_protected:Npn \__tl_replace:NnNNNnn #1#2#3#4#5#6#7
   {
     \tl_if_empty:nTF {#6}
       {
-        \msg_error:nnx { kernel } { empty-search-pattern }
+        \msg_error:nne { kernel } { empty-search-pattern }
           { \tl_to_str:n {#7} }
       }
       {
@@ -3684,7 +3766,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \group_align_safe_begin:
     \cs_set:Npn \__tl_replace_wrap:w ##1 #1 ##2
       { \__kernel_exp_not:w \exp_after:wN { \use_none:nn ##1 } ##2 }
-    \cs_set:Npx \__tl_replace_next:w ##1 #5
+    \cs_set:Npe \__tl_replace_next:w ##1 #5
       {
         \exp_not:N \__tl_replace_wrap:w ##1
         \exp_not:n { #1 }
@@ -3711,14 +3793,16 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \tl_replace_once:Nnn #1 {#2} { } }
 \cs_new_protected:Npn \tl_gremove_once:Nn #1#2
   { \tl_greplace_once:Nnn #1 {#2} { } }
-\cs_generate_variant:Nn \tl_remove_once:Nn  { NV , Nx , c , cV , cx }
-\cs_generate_variant:Nn \tl_gremove_once:Nn { NV , Nx , c , cV , cx }
+\cs_generate_variant:Nn \tl_remove_once:Nn  { NV , Ne , c , cV , ce }
+\cs_generate_variant:Nn \tl_gremove_once:Nn { NV , Ne , c , cV , ce }
 \cs_new_protected:Npn \tl_remove_all:Nn #1#2
   { \tl_replace_all:Nnn #1 {#2} { } }
 \cs_new_protected:Npn \tl_gremove_all:Nn #1#2
   { \tl_greplace_all:Nnn #1 {#2} { } }
-\cs_generate_variant:Nn \tl_remove_all:Nn  { NV , Nx , c , cV , cx }
-\cs_generate_variant:Nn \tl_gremove_all:Nn { NV , Nx , c , cV , cx }
+\cs_generate_variant:Nn \tl_remove_all:Nn  { NV , Ne , c , cV , ce }
+\cs_generate_variant:Nn \tl_remove_all:Nn  { Nx , cx }
+\cs_generate_variant:Nn \tl_gremove_all:Nn { NV , Ne , c , cV , ce }
+\cs_generate_variant:Nn \tl_gremove_all:Nn { Nx , cx }
 \prg_new_conditional:Npnn \tl_if_empty:N #1 { p , T , F , TF }
   {
     \if_meaning:w #1 \c_empty_tl
@@ -3794,7 +3878,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \prg_return_false:
     \fi:
   }
-\prg_generate_conditional_variant:Nnn \tl_if_eq:nn { V , nV , x , nx } { TF , T , F }
+\prg_generate_conditional_variant:Nnn \tl_if_eq:nn
+  { nV , ne , nx , e , ee , x , xx }
+  { TF , T , F }
 \cs_new_protected:Npn \tl_if_in:NnT  { \exp_args:No \tl_if_in:nnT  }
 \cs_new_protected:Npn \tl_if_in:NnF  { \exp_args:No \tl_if_in:nnF  }
 \cs_new_protected:Npn \tl_if_in:NnTF { \exp_args:No \tl_if_in:nnTF }
@@ -3829,6 +3915,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new:Npn \tl_if_single:NT  { \exp_args:No \tl_if_single:nT  }
 \cs_new:Npn \tl_if_single:NF  { \exp_args:No \tl_if_single:nF  }
 \cs_new:Npn \tl_if_single:NTF { \exp_args:No \tl_if_single:nTF }
+\prg_generate_conditional_variant:Nnn \tl_if_single:N {c} { p , T , F , TF }
 \prg_new_conditional:Npnn \tl_if_single:n #1 { p , T , F , TF }
   {
     \if:w \scan_stop: \exp_after:wN \__tl_if_single:nnw
@@ -3990,14 +4077,14 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { \__tl_trim_mark: #1 }
       { \__kernel_exp_not:w \exp_after:wN }
   }
-\cs_generate_variant:Nn \tl_trim_spaces:n { o }
+\cs_generate_variant:Nn \tl_trim_spaces:n { V , v , e , o }
 \cs_new:Npn \tl_trim_spaces_apply:nN #1#2
   { \__tl_trim_spaces:nn { \__tl_trim_mark: #1 } { \exp_args:No #2 } }
 \cs_generate_variant:Nn \tl_trim_spaces_apply:nN { o }
 \cs_new_protected:Npn \tl_trim_spaces:N #1
-  { \__kernel_tl_set:Nx #1 { \exp_args:No \tl_trim_spaces:n {#1} } }
+  { \__kernel_tl_set:Ne #1 { \exp_args:No \tl_trim_spaces:n {#1} } }
 \cs_new_protected:Npn \tl_gtrim_spaces:N #1
-  { \__kernel_tl_gset:Nx #1 { \exp_args:No \tl_trim_spaces:n {#1} } }
+  { \__kernel_tl_gset:Ne #1 { \exp_args:No \tl_trim_spaces:n {#1} } }
 \cs_generate_variant:Nn \tl_trim_spaces:N  { c }
 \cs_generate_variant:Nn \tl_gtrim_spaces:N { c }
 \cs_set_protected:Npn \__tl_tmp:w #1
@@ -4201,7 +4288,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       {##1}
   }
 \__tl_tmp:w { ~ }
-\exp_args:Nnx \use:n { \cs_new:Npn \__tl_act_loop:w #1 \s__tl_act_stop }
+\exp_args:Nne \use:n { \cs_new:Npn \__tl_act_loop:w #1 \s__tl_act_stop }
   {
     \exp_not:o { \__tl_act_if_head_is_space:nTF {#1} }
       \exp_not:N \__tl_act_space:wwNNN
@@ -4267,9 +4354,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new:Npn \__tl_reverse_space:
   { \__tl_act_reverse_output:n { ~ } }
 \cs_new_protected:Npn \tl_reverse:N #1
-  { \__kernel_tl_set:Nx #1 { \exp_args:No \tl_reverse:n { #1 } } }
+  { \__kernel_tl_set:Ne #1 { \exp_args:No \tl_reverse:n { #1 } } }
 \cs_new_protected:Npn \tl_greverse:N #1
-  { \__kernel_tl_gset:Nx #1 { \exp_args:No \tl_reverse:n { #1 } } }
+  { \__kernel_tl_gset:Ne #1 { \exp_args:No \tl_reverse:n { #1 } } }
 \cs_generate_variant:Nn \tl_reverse:N  { c }
 \cs_generate_variant:Nn \tl_greverse:N { c }
 \cs_new:Npn \tl_item:nn #1#2
@@ -4415,14 +4502,14 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
               { \token_to_str:N #2 = \__kernel_exp_not:w \exp_after:wN {#2} }
           }
           {
-            \msg_error:nnxxx { kernel } { bad-type }
+            \msg_error:nneee { kernel } { bad-type }
               { \token_to_str:N #2 } { \token_to_meaning:N #2 } { tl }
           }
       }
   }
 \cs_new_protected:Npn \tl_show:n #1
   { \iow_wrap:nnnN { >~ \tl_to_str:n {#1} . } { } { } \__tl_show:n }
-\cs_generate_variant:Nn \tl_show:n { x }
+\cs_generate_variant:Nn \tl_show:n { e , x }
 \cs_new_protected:Npn \__tl_show:n #1
   {
     \tl_set:Nf \l__tl_internal_a_tl { \__tl_show:w #1 \s__tl_stop }
@@ -4438,7 +4525,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new:Npn \__tl_show:w #1 > #2 . \s__tl_stop {#2}
 \cs_new_protected:Npn \tl_log:n #1
   { \iow_wrap:nnnN { > ~ \tl_to_str:n {#1} . } { } { } \iow_log:n }
-\cs_generate_variant:Nn \tl_log:n { x }
+\cs_generate_variant:Nn \tl_log:n { e , x }
 \cs_new_protected:Npn \__kernel_chk_tl_type:NnnT #1#2#3#4
   {
     \__kernel_chk_defined:NT #1
@@ -4446,17 +4533,17 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \exp_args:Nf \tl_if_empty:nTF
           { \cs_prefix_spec:N #1 \cs_parameter_spec:N #1 }
           {
-            \tl_set:Nx \l__tl_internal_a_tl {#3}
+            \tl_set:Ne \l__tl_internal_a_tl {#3}
             \tl_if_eq:NNTF #1 \l__tl_internal_a_tl
               {#4}
               {
-                \msg_error:nnxxxx { kernel } { bad-type }
+                \msg_error:nneeee { kernel } { bad-type }
                   { \token_to_str:N #1 } { \tl_to_str:N #1 }
                   {#2} { \tl_to_str:N \l__tl_internal_a_tl }
               }
           }
           {
-            \msg_error:nnxxx { kernel } { bad-type }
+            \msg_error:nneee { kernel } { bad-type }
               { \token_to_str:N #1 } { \token_to_meaning:N #1 } {#2}
           }
       }
@@ -4510,12 +4597,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     {
       \tl_if_blank:nF {#1}
         {
-          \cs_new_protected:cpx { str_ #1 :Nn } ##1##2
+          \cs_new_protected:cpe { str_ #1 :Nn } ##1##2
             {
-              \exp_not:c { tl_ #1 :Nx } ##1
+              \exp_not:c { tl_ #1 :Ne } ##1
                 { \exp_not:N \tl_to_str:n {##2} }
             }
-          \cs_generate_variant:cn { str_ #1 :Nn } { NV , Nx , cn , cV , cx }
+          \cs_generate_variant:cn { str_ #1 :Nn }
+            { NV , Ne , Nx , cn , cV , ce , cx }
           \__str_tmp:n
         }
     }
@@ -4530,13 +4618,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     { }
 \group_end:
 \cs_new_protected:Npn \str_replace_once:Nnn
-  { \__str_replace:NNNnn \prg_do_nothing: \__kernel_tl_set:Nx  }
+  { \__str_replace:NNNnn \prg_do_nothing: \__kernel_tl_set:Ne  }
 \cs_new_protected:Npn \str_greplace_once:Nnn
-  { \__str_replace:NNNnn \prg_do_nothing: \__kernel_tl_gset:Nx }
+  { \__str_replace:NNNnn \prg_do_nothing: \__kernel_tl_gset:Ne }
 \cs_new_protected:Npn \str_replace_all:Nnn
-  { \__str_replace:NNNnn \__str_replace_next:w \__kernel_tl_set:Nx  }
+  { \__str_replace:NNNnn \__str_replace_next:w \__kernel_tl_set:Ne  }
 \cs_new_protected:Npn \str_greplace_all:Nnn
-  { \__str_replace:NNNnn \__str_replace_next:w \__kernel_tl_gset:Nx }
+  { \__str_replace:NNNnn \__str_replace_next:w \__kernel_tl_gset:Ne }
 \cs_generate_variant:Nn \str_replace_once:Nnn  { c }
 \cs_generate_variant:Nn \str_greplace_once:Nnn { c }
 \cs_generate_variant:Nn \str_replace_all:Nnn   { c }
@@ -4545,10 +4633,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \tl_if_empty:nTF {#4}
       {
-        \msg_error:nnx { kernel } { empty-search-pattern } {#5}
+        \msg_error:nne { kernel } { empty-search-pattern } {#5}
       }
       {
-        \use:x
+        \use:e
           {
             \exp_not:n { \__str_replace_aux:NNNnnn #1 #2 #3 }
               { \tl_to_str:N #3 }
@@ -4625,7 +4713,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { c , Nc , cc } { T , F , TF , p }
 \prg_new_protected_conditional:Npnn \str_if_in:Nn #1#2 { T , F , TF }
   {
-    \use:x
+    \use:e
       { \tl_if_in:nnTF { \tl_to_str:N #1 } { \tl_to_str:n {#2} } }
       { \prg_return_true: } { \prg_return_false: }
   }
@@ -4633,7 +4721,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { c } { T , F , TF }
 \prg_new_protected_conditional:Npnn \str_if_in:nn #1#2 { T , F , TF }
   {
-    \use:x
+    \use:e
       { \tl_if_in:nnTF { \tl_to_str:n {#1} } { \tl_to_str:n {#2} } }
       { \prg_return_true: } { \prg_return_false: }
   }
@@ -4727,7 +4815,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \int_gincr:N \g__kernel_prg_map_int
     \cs_gset_protected:cpn
       { __str_map_ \int_use:N \g__kernel_prg_map_int :w } ##1 {#2}
-    \use:x
+    \use:e
       {
         \exp_not:N \__str_map_inline:NN
         \exp_not:c { __str_map_ \int_use:N \g__kernel_prg_map_int :w }
@@ -4748,7 +4836,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \str_map_variable:nNn #1#2#3
   {
-    \use:x
+    \use:e
       {
         \exp_not:n { \__str_map_variable:NnN #2 {#3} }
         \__kernel_str_to_other_fast:n {#1}
@@ -5098,7 +5186,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   \cs_new:Npn \__str_change_case_codepoint:nN #1#2
     { \__str_change_case_char:fnn { \int_eval:n {`#2} } {#1} {#2} }
 \else:
-    \cs_new:Npx \__str_change_case_codepoint:nN #1#2
+    \cs_new:Npe \__str_change_case_codepoint:nN #1#2
       {
         \exp_not:N \int_compare:nNnTF {`#2} > { "80 }
           {
@@ -5186,19 +5274,19 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new:Npn \str_mdfive_hash:n #1 { \tex_mdfivesum:D { \tl_to_str:n {#1} } }
 \cs_new:Npn \str_mdfive_hash:e #1 { \tex_mdfivesum:D {#1} }
-\str_const:Nx \c_ampersand_str   { \cs_to_str:N \& }
-\str_const:Nx \c_atsign_str      { \cs_to_str:N \@ }
-\str_const:Nx \c_backslash_str   { \cs_to_str:N \\ }
-\str_const:Nx \c_left_brace_str  { \cs_to_str:N \{ }
-\str_const:Nx \c_right_brace_str { \cs_to_str:N \} }
-\str_const:Nx \c_circumflex_str  { \cs_to_str:N \^ }
-\str_const:Nx \c_colon_str       { \cs_to_str:N \: }
-\str_const:Nx \c_dollar_str      { \cs_to_str:N \$ }
-\str_const:Nx \c_hash_str        { \cs_to_str:N \# }
-\str_const:Nx \c_percent_str     { \cs_to_str:N \% }
-\str_const:Nx \c_tilde_str       { \cs_to_str:N \~ }
-\str_const:Nx \c_underscore_str  { \cs_to_str:N \_ }
-\str_const:Nx \c_zero_str        { 0 }
+\str_const:Ne \c_ampersand_str   { \cs_to_str:N \& }
+\str_const:Ne \c_atsign_str      { \cs_to_str:N \@ }
+\str_const:Ne \c_backslash_str   { \cs_to_str:N \\ }
+\str_const:Ne \c_left_brace_str  { \cs_to_str:N \{ }
+\str_const:Ne \c_right_brace_str { \cs_to_str:N \} }
+\str_const:Ne \c_circumflex_str  { \cs_to_str:N \^ }
+\str_const:Ne \c_colon_str       { \cs_to_str:N \: }
+\str_const:Ne \c_dollar_str      { \cs_to_str:N \$ }
+\str_const:Ne \c_hash_str        { \cs_to_str:N \# }
+\str_const:Ne \c_percent_str     { \cs_to_str:N \% }
+\str_const:Ne \c_tilde_str       { \cs_to_str:N \~ }
+\str_const:Ne \c_underscore_str  { \cs_to_str:N \_ }
+\str_const:Ne \c_zero_str        { 0 }
 \str_new:N \l_tmpa_str
 \str_new:N \l_tmpb_str
 \str_new:N \g_tmpa_str
@@ -5258,22 +5346,22 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_eq:NN \seq_gset_eq:cc \tl_gset_eq:cc
 \cs_new_protected:Npn \seq_set_from_clist:NN #1#2
   {
-    \__kernel_tl_set:Nx #1
+    \__kernel_tl_set:Ne #1
       { \s__seq \clist_map_function:NN #2 \__seq_wrap_item:n }
   }
 \cs_new_protected:Npn \seq_set_from_clist:Nn #1#2
   {
-    \__kernel_tl_set:Nx #1
+    \__kernel_tl_set:Ne #1
       { \s__seq \clist_map_function:nN {#2} \__seq_wrap_item:n }
   }
 \cs_new_protected:Npn \seq_gset_from_clist:NN #1#2
   {
-    \__kernel_tl_gset:Nx #1
+    \__kernel_tl_gset:Ne #1
       { \s__seq \clist_map_function:NN #2 \__seq_wrap_item:n }
   }
 \cs_new_protected:Npn \seq_gset_from_clist:Nn #1#2
   {
-    \__kernel_tl_gset:Nx #1
+    \__kernel_tl_gset:Ne #1
       { \s__seq \clist_map_function:nN {#2} \__seq_wrap_item:n }
   }
 \cs_generate_variant:Nn \seq_set_from_clist:NN  {     Nc }
@@ -5284,18 +5372,18 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_generate_variant:Nn \seq_gset_from_clist:Nn { c      }
 \cs_new_protected:Npn \seq_const_from_clist:Nn #1#2
   {
-    \tl_const:Nx #1
+    \tl_const:Ne #1
       { \s__seq \clist_map_function:nN {#2} \__seq_wrap_item:n }
   }
 \cs_generate_variant:Nn \seq_const_from_clist:Nn { c }
 \cs_new_protected:Npn \seq_set_split:Nnn
-  { \__seq_set_split:NNNnn \__kernel_tl_set:Nx \tl_trim_spaces:n }
+  { \__seq_set_split:NNNnn \__kernel_tl_set:Ne \tl_trim_spaces:n }
 \cs_new_protected:Npn \seq_gset_split:Nnn
-  { \__seq_set_split:NNNnn \__kernel_tl_gset:Nx \tl_trim_spaces:n }
+  { \__seq_set_split:NNNnn \__kernel_tl_gset:Ne \tl_trim_spaces:n }
 \cs_new_protected:Npn \seq_set_split_keep_spaces:Nnn
-  { \__seq_set_split:NNNnn \__kernel_tl_set:Nx \exp_not:n }
+  { \__seq_set_split:NNNnn \__kernel_tl_set:Ne \exp_not:n }
 \cs_new_protected:Npn \seq_gset_split_keep_spaces:Nnn
-  { \__seq_set_split:NNNnn \__kernel_tl_gset:Nx \exp_not:n }
+  { \__seq_set_split:NNNnn \__kernel_tl_gset:Ne \exp_not:n }
 \cs_new_protected:Npn \__seq_set_split:NNNnn #1#2#3#4#5
   {
     \tl_if_empty:nTF {#4}
@@ -5315,7 +5403,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
             \__seq_set_split_end:
             \__seq_set_split:Nw #2 \prg_do_nothing:
           }
-        \__kernel_tl_set:Nx \l__seq_internal_a_tl { \l__seq_internal_a_tl }
+        \__kernel_tl_set:Ne \l__seq_internal_a_tl { \l__seq_internal_a_tl }
       }
     #1 #3 { \s__seq \l__seq_internal_a_tl }
   }
@@ -5327,8 +5415,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new:Npn \__seq_set_split:w #1 \__seq_set_split_end:
   { \__seq_wrap_item:n {#1} }
-\cs_generate_variant:Nn \seq_set_split:Nnn  { NV , NnV , NVV , Nnx , Nxx }
-\cs_generate_variant:Nn \seq_gset_split:Nnn { NV , NnV , NVV , Nnx , Nxx }
+\cs_generate_variant:Nn \seq_set_split:Nnn  { NV , NnV , NVV , Nne , Nee }
+\cs_generate_variant:Nn \seq_set_split:Nnn  { Nnx , Nxx }
+\cs_generate_variant:Nn \seq_gset_split:Nnn { NV , NnV , NVV , Nne , Nee }
+\cs_generate_variant:Nn \seq_gset_split:Nnn { Nnx , Nxx }
 \cs_generate_variant:Nn \seq_set_split_keep_spaces:Nnn  { NnV }
 \cs_generate_variant:Nn \seq_gset_split_keep_spaces:Nnn { NnV }
 \cs_new_protected:Npn \seq_concat:NNN #1#2#3
@@ -5343,7 +5433,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { TF , T , F , p }
 \cs_new_protected:Npn \seq_put_left:Nn #1#2
   {
-    \__kernel_tl_set:Nx #1
+    \__kernel_tl_set:Ne #1
       {
         \exp_not:n { \s__seq \__seq_item:n {#2} }
         \exp_not:f { \exp_after:wN \__seq_put_left_aux:w #1 }
@@ -5351,25 +5441,25 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \seq_gput_left:Nn #1#2
   {
-    \__kernel_tl_gset:Nx #1
+    \__kernel_tl_gset:Ne #1
       {
         \exp_not:n { \s__seq \__seq_item:n {#2} }
         \exp_not:f { \exp_after:wN \__seq_put_left_aux:w #1 }
       }
   }
 \cs_new:Npn \__seq_put_left_aux:w \s__seq { \exp_stop_f: }
-\cs_generate_variant:Nn \seq_put_left:Nn  {     NV , Nv , No , Nx }
-\cs_generate_variant:Nn \seq_put_left:Nn  { c , cV , cv , co , cx }
-\cs_generate_variant:Nn \seq_gput_left:Nn  {     NV , Nv , No , Nx }
-\cs_generate_variant:Nn \seq_gput_left:Nn  { c , cV , cv , co , cx }
+\cs_generate_variant:Nn \seq_put_left:Nn  {     NV , Nv , Ne , No , Nx }
+\cs_generate_variant:Nn \seq_put_left:Nn  { c , cV , cv , ce , co ,cx }
+\cs_generate_variant:Nn \seq_gput_left:Nn {     NV , Nv , Ne , No , Nx }
+\cs_generate_variant:Nn \seq_gput_left:Nn { c , cV , cv , ce , co , cx }
 \cs_new_protected:Npn \seq_put_right:Nn #1#2
   { \tl_put_right:Nn #1 { \__seq_item:n {#2} } }
 \cs_new_protected:Npn \seq_gput_right:Nn #1#2
   { \tl_gput_right:Nn #1 { \__seq_item:n {#2} } }
-\cs_generate_variant:Nn \seq_gput_right:Nn {     NV , Nv , No , Nx }
-\cs_generate_variant:Nn \seq_gput_right:Nn { c , cV , cv , co , cx }
-\cs_generate_variant:Nn \seq_put_right:Nn {     NV , Nv , No , Nx }
-\cs_generate_variant:Nn \seq_put_right:Nn { c , cV , cv , co , cx }
+\cs_generate_variant:Nn \seq_put_right:Nn  {     NV , Nv , Ne , No , Nx }
+\cs_generate_variant:Nn \seq_put_right:Nn  { c , cV , cv , ce , co , cx }
+\cs_generate_variant:Nn \seq_gput_right:Nn {     NV , Nv , Ne , No , Nx }
+\cs_generate_variant:Nn \seq_gput_right:Nn { c , cV , cv , ce , co , cx }
 \cs_new:Npn \__seq_wrap_item:n #1 { \exp_not:n { \__seq_item:n {#1} } }
 \seq_new:N \l__seq_remove_seq
 \cs_new_protected:Npn \seq_remove_duplicates:N
@@ -5389,9 +5479,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_generate_variant:Nn \seq_remove_duplicates:N  { c }
 \cs_generate_variant:Nn \seq_gremove_duplicates:N { c }
 \cs_new_protected:Npn \seq_remove_all:Nn
-  { \__seq_remove_all_aux:NNn \__kernel_tl_set:Nx }
+  { \__seq_remove_all_aux:NNn \__kernel_tl_set:Ne }
 \cs_new_protected:Npn \seq_gremove_all:Nn
-  { \__seq_remove_all_aux:NNn \__kernel_tl_gset:Nx }
+  { \__seq_remove_all_aux:NNn \__kernel_tl_gset:Ne }
 \cs_new_protected:Npn \__seq_remove_all_aux:NNn #1#2#3
   {
     \__seq_push_item_def:n
@@ -5412,19 +5502,21 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     #1 #2 {#2}
     \__seq_pop_item_def:
   }
-\cs_generate_variant:Nn \seq_remove_all:Nn  { NV , Nx , c , cV , cx }
-\cs_generate_variant:Nn \seq_gremove_all:Nn { NV , Nx , c , cV , cx }
+\cs_generate_variant:Nn \seq_remove_all:Nn  { NV , Ne , c , cV , ce }
+\cs_generate_variant:Nn \seq_remove_all:Nn  { Nx , cx }
+\cs_generate_variant:Nn \seq_gremove_all:Nn { NV , Ne , c , cV , ce }
+\cs_generate_variant:Nn \seq_gremove_all:Nn { Nx , cx }
 \cs_new_eq:NN \__seq_int_eval:w \tex_numexpr:D
 \cs_new_protected:Npn \seq_set_item:Nnn #1#2#3
-  { \__seq_set_item:NnnNN #1 {#2} {#3} \__kernel_tl_set:Nx \use_i:nn }
+  { \__seq_set_item:NnnNN #1 {#2} {#3} \__kernel_tl_set:Ne \use_i:nn }
 \cs_new_protected:Npn \seq_gset_item:Nnn #1#2#3
-  { \__seq_set_item:NnnNN #1 {#2} {#3} \__kernel_tl_gset:Nx \use_i:nn }
+  { \__seq_set_item:NnnNN #1 {#2} {#3} \__kernel_tl_gset:Ne \use_i:nn }
 \cs_generate_variant:Nn \seq_set_item:Nnn { c }
 \cs_generate_variant:Nn \seq_gset_item:Nnn { c }
 \prg_new_protected_conditional:Npnn \seq_set_item:Nnn #1#2#3 { TF , T , F }
-  { \__seq_set_item:NnnNN #1 {#2} {#3} \__kernel_tl_set:Nx \use_ii:nn }
+  { \__seq_set_item:NnnNN #1 {#2} {#3} \__kernel_tl_set:Ne \use_ii:nn }
 \prg_new_protected_conditional:Npnn \seq_gset_item:Nnn #1#2#3 { TF , T , F }
-  { \__seq_set_item:NnnNN #1 {#2} {#3} \__kernel_tl_gset:Nx \use_ii:nn }
+  { \__seq_set_item:NnnNN #1 {#2} {#3} \__kernel_tl_gset:Ne \use_ii:nn }
 \prg_generate_conditional_variant:Nnn \seq_set_item:Nnn { c } { TF , T , F }
 \prg_generate_conditional_variant:Nnn \seq_gset_item:Nnn { c } { TF , T , F }
 \cs_new_protected:Npn \__seq_set_item:NnnNN #1#2#3
@@ -5450,7 +5542,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     #6
       {
-        \msg_error:nnxxx { seq } { item-too-large }
+        \msg_error:nneee { seq } { item-too-large }
           { \token_to_str:N #3 } {#2} {#1}
       }
       { \prg_return_false: }
@@ -5481,9 +5573,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     #5 #2
   }
 \cs_new_protected:Npn \seq_reverse:N
-  { \__seq_reverse:NN \__kernel_tl_set:Nx }
+  { \__seq_reverse:NN \__kernel_tl_set:Ne }
 \cs_new_protected:Npn \seq_greverse:N
-  { \__seq_reverse:NN \__kernel_tl_gset:Nx }
+  { \__seq_reverse:NN \__kernel_tl_gset:Ne }
 \cs_new_protected:Npn \__seq_reverse:NN #1 #2
   {
     \cs_set_eq:NN \__seq_tmp:w \__seq_item:n
@@ -5515,7 +5607,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \int_compare:nNnTF { \seq_count:N #2 } > \c_max_register_int
       {
-        \msg_error:nnx { seq } { shuffle-too-large }
+        \msg_error:nne { seq } { shuffle-too-large }
           { \token_to_str:N #2 }
       }
       {
@@ -5528,7 +5620,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           \seq_gclear:N \g__seq_internal_seq
           \int_step_inline:nn \l__seq_internal_a_int
             {
-              \seq_gput_right:Nx \g__seq_internal_seq
+              \seq_gput_right:Ne \g__seq_internal_seq
                 { \tex_the:D \tex_toks:D ##1 }
             }
         \group_end:
@@ -5567,7 +5659,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new:Npn \__seq_if_in:
   { \prg_break:n { \group_end: \prg_return_true: } }
 \prg_generate_conditional_variant:Nnn \seq_if_in:Nn
-  { NV , Nv , No , Nx , c , cV , cv , co , cx } { T , F , TF }
+  { NV , Nv , Ne , No , Nx , c , cV , cv , ce , co , cx } { T , F , TF }
 \cs_new_protected:Npn \__seq_pop:NNNN #1#2#3#4
   {
     \if_meaning:w #3 \c_empty_seq
@@ -5588,7 +5680,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \seq_get_left:NN #1#2
   {
-    \__kernel_tl_set:Nx #2
+    \__kernel_tl_set:Ne #2
       {
         \exp_after:wN \__seq_get_left:wnw
         #1 \__seq_item:n { \q_no_value } \s__seq_stop
@@ -5613,7 +5705,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_generate_variant:Nn \seq_gpop_left:NN { c }
 \cs_new_protected:Npn \seq_get_right:NN #1#2
   {
-    \__kernel_tl_set:Nx #2
+    \__kernel_tl_set:Ne #2
       {
         \exp_after:wN \use_i_ii:nnn
         \exp_after:wN \__seq_get_right_loop:nw
@@ -5630,9 +5722,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new:Npn \__seq_get_right_end:NnN #1#2#3 { \exp_not:n {#2} }
 \cs_generate_variant:Nn \seq_get_right:NN { c }
 \cs_new_protected:Npn \seq_pop_right:NN
-  { \__seq_pop:NNNN \__seq_pop_right:NNN \__kernel_tl_set:Nx }
+  { \__seq_pop:NNNN \__seq_pop_right:NNN \__kernel_tl_set:Ne }
 \cs_new_protected:Npn \seq_gpop_right:NN
-  { \__seq_pop:NNNN \__seq_pop_right:NNN \__kernel_tl_gset:Nx }
+  { \__seq_pop:NNNN \__seq_pop_right:NNN \__kernel_tl_gset:Ne }
 \cs_new_protected:Npn \__seq_pop_right:NNN #1#2#3
   {
     \cs_set_eq:NN \__seq_tmp:w \__seq_item:n
@@ -5644,7 +5736,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         #2
         {
           \if_false: { \fi: }
-          \__kernel_tl_set:Nx #3
+          \__kernel_tl_set:Ne #3
         }
         { } \use_none:nn
     \cs_set_eq:NN \__seq_item:n \__seq_tmp:w
@@ -5672,10 +5764,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \__seq_pop_TF:NNNN \__seq_pop_left:NNN \tl_gset:Nn #1 #2 }
 \prg_new_protected_conditional:Npnn \seq_pop_right:NN #1#2
   { T , F , TF }
-  { \__seq_pop_TF:NNNN \__seq_pop_right:NNN \__kernel_tl_set:Nx #1 #2 }
+  { \__seq_pop_TF:NNNN \__seq_pop_right:NNN \__kernel_tl_set:Ne #1 #2 }
 \prg_new_protected_conditional:Npnn \seq_gpop_right:NN #1#2
   { T , F , TF }
-  { \__seq_pop_TF:NNNN \__seq_pop_right:NNN \__kernel_tl_gset:Nx #1 #2 }
+  { \__seq_pop_TF:NNNN \__seq_pop_right:NNN \__kernel_tl_gset:Ne #1 #2 }
 \prg_generate_conditional_variant:Nnn \seq_pop_left:NN { c }
   { T , F , TF }
 \prg_generate_conditional_variant:Nnn \seq_gpop_left:NN { c }
@@ -5747,10 +5839,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \__seq_push_item_def:
     \cs_gset:Npn \__seq_item:n ##1
   }
-\cs_new_protected:Npn \__seq_push_item_def:x
+\cs_new_protected:Npn \__seq_push_item_def:e
   {
     \__seq_push_item_def:
-    \cs_gset:Npx \__seq_item:n ##1
+    \cs_gset:Npe \__seq_item:n ##1
   }
 \cs_new_protected:Npn \__seq_push_item_def:
   {
@@ -5795,7 +5887,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \seq_map_variable:NNn #1#2#3
   {
-    \__seq_push_item_def:x
+    \__seq_push_item_def:e
       {
         \tl_set:Nn \exp_not:N #2 {##1}
         \exp_not:n {#3}
@@ -5861,9 +5953,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_generate_variant:Nn \seq_map_pairwise_function:NNN { Nc , c , cc }
 \cs_new_protected:Npn \seq_set_map_x:NNn
-  { \__seq_set_map_x:NNNn \__kernel_tl_set:Nx }
+  { \__seq_set_map_x:NNNn \__kernel_tl_set:Ne }
 \cs_new_protected:Npn \seq_gset_map_x:NNn
-  { \__seq_set_map_x:NNNn \__kernel_tl_gset:Nx }
+  { \__seq_set_map_x:NNNn \__kernel_tl_gset:Ne }
 \cs_new_protected:Npn \__seq_set_map_x:NNNn #1#2#3#4
   {
     \__seq_push_item_def:n { \exp_not:N \__seq_item:n {#4} }
@@ -5871,9 +5963,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \__seq_pop_item_def:
   }
 \cs_new_protected:Npn \seq_set_map:NNn
-  { \__seq_set_map:NNNn \__kernel_tl_set:Nx }
+  { \__seq_set_map:NNNn \__kernel_tl_set:Ne }
 \cs_new_protected:Npn \seq_gset_map:NNn
-  { \__seq_set_map:NNNn \__kernel_tl_gset:Nx }
+  { \__seq_set_map:NNNn \__kernel_tl_gset:Ne }
 \cs_new_protected:Npn \__seq_set_map:NNNn #1#2#3#4
   {
     \__seq_push_item_def:n { \exp_not:n { \__seq_item:n {#4} } }
@@ -5941,26 +6033,12 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new:Npn \seq_use:Nn #1#2
   { \seq_use:Nnnn #1 {#2} {#2} {#2} }
 \cs_generate_variant:Nn \seq_use:Nn { c }
-\cs_new_eq:NN \seq_push:Nn  \seq_put_left:Nn
-\cs_new_eq:NN \seq_push:NV  \seq_put_left:NV
-\cs_new_eq:NN \seq_push:Nv  \seq_put_left:Nv
-\cs_new_eq:NN \seq_push:No  \seq_put_left:No
-\cs_new_eq:NN \seq_push:Nx  \seq_put_left:Nx
-\cs_new_eq:NN \seq_push:cn  \seq_put_left:cn
-\cs_new_eq:NN \seq_push:cV  \seq_put_left:cV
-\cs_new_eq:NN \seq_push:cv  \seq_put_left:cv
-\cs_new_eq:NN \seq_push:co  \seq_put_left:co
-\cs_new_eq:NN \seq_push:cx  \seq_put_left:cx
+\cs_new_eq:NN \seq_push:Nn \seq_put_left:Nn
+\cs_generate_variant:Nn \seq_push:Nn { NV , Nv , Ne , c , cV , cv , ce }
+\cs_generate_variant:Nn \seq_push:Nn { No , Nx , co , cx }
 \cs_new_eq:NN \seq_gpush:Nn \seq_gput_left:Nn
-\cs_new_eq:NN \seq_gpush:NV \seq_gput_left:NV
-\cs_new_eq:NN \seq_gpush:Nv \seq_gput_left:Nv
-\cs_new_eq:NN \seq_gpush:No \seq_gput_left:No
-\cs_new_eq:NN \seq_gpush:Nx \seq_gput_left:Nx
-\cs_new_eq:NN \seq_gpush:cn \seq_gput_left:cn
-\cs_new_eq:NN \seq_gpush:cV \seq_gput_left:cV
-\cs_new_eq:NN \seq_gpush:cv \seq_gput_left:cv
-\cs_new_eq:NN \seq_gpush:co \seq_gput_left:co
-\cs_new_eq:NN \seq_gpush:cx \seq_gput_left:cx
+\cs_generate_variant:Nn \seq_gpush:Nn { NV , Nv , Ne , c , cV , cv , ce }
+\cs_generate_variant:Nn \seq_gpush:Nn { No , Nx , co , cx }
 \cs_new_eq:NN \seq_get:NN \seq_get_left:NN
 \cs_new_eq:NN \seq_get:cN \seq_get_left:cN
 \cs_new_eq:NN \seq_pop:NN \seq_pop_left:NN
@@ -5973,9 +6051,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \prg_new_eq_conditional:NNn \seq_pop:cN  \seq_pop_left:cN  { T , F , TF }
 \prg_new_eq_conditional:NNn \seq_gpop:NN \seq_gpop_left:NN { T , F , TF }
 \prg_new_eq_conditional:NNn \seq_gpop:cN \seq_gpop_left:cN { T , F , TF }
-\cs_new_protected:Npn \seq_show:N { \__seq_show:NN \msg_show:nnxxxx }
+\cs_new_protected:Npn \seq_show:N { \__seq_show:NN \msg_show:nneeee }
 \cs_generate_variant:Nn \seq_show:N { c }
-\cs_new_protected:Npn \seq_log:N { \__seq_show:NN \msg_log:nnxxxx }
+\cs_new_protected:Npn \seq_log:N { \__seq_show:NN \msg_log:nneeee }
 \cs_generate_variant:Nn \seq_log:N { c }
 \cs_new_protected:Npn \__seq_show:NN #1#2
   {
@@ -6110,7 +6188,8 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_generate_variant:Nn \int_new:N { c }
 \cs_new_protected:Npn \int_const:Nn #1#2
-  { \exp_args:Nx \__int_const:nN { \int_eval:n {#2} } #1 }
+  { \__int_const:eN { \int_eval:n {#2} } #1 }
+\cs_generate_variant:Nn \int_const:Nn { c }
 \cs_new_protected:Npn \__int_const:nN #1#2
   {
     \int_compare:nNnTF {#1} < \c_zero_int
@@ -6131,7 +6210,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
     #2 = \__int_eval:w #1 \__int_eval_end:
   }
-\cs_generate_variant:Nn \int_const:Nn { c }
+\cs_generate_variant:Nn \__int_const:nN { e }
 \if_int_odd:w 0
   \cs_if_exist:NT \tex_luatexversion:D { 1 }
   \cs_if_exist:NT \tex_omathchardef:D  { 1 }
@@ -6436,7 +6515,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \int_gincr:N \g__kernel_prg_map_int
     \exp_args:NNc \__int_step:NNnnnn
-      \cs_gset_protected:Npx
+      \cs_gset_protected:Npe
       { __int_map_ \int_use:N \g__kernel_prg_map_int :w }
       {#1}{#2}{#3}
       {
@@ -6456,7 +6535,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \int_compare:nNnTF {#1} > {#2}
       {
-        \exp_args:NNo \exp_args:No \__int_to_symbols:nnnn
+        \__int_to_symbols:ennn
           {
             \int_case:nn
               { 1 + \int_mod:nn { #1 - 1 } {#2} }
@@ -6472,6 +6551,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { \int_div_truncate:nn { #2 - 1 } {#3} } {#3} {#4}
     #1
   }
+\cs_generate_variant:Nn \__int_to_symbols:nnnn { e }
 \cs_new:Npn \int_to_alph:n #1
   {
     \int_to_symbols:nnn {#1} { 26 }
@@ -6859,7 +6939,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \exp_args:Nc \__kernel_chk_defined:NT { flag~#2 }
       {
-        \exp_args:Nx #1
+        \exp_args:Ne #1
           { \tl_to_str:n { flag~#2~height } = \flag_height:n {#2} }
       }
   }
@@ -6974,11 +7054,11 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       {
         \token_case_meaning:NnF #2
           {
-            \c_true_bool { \exp_args:Nx #1 { \token_to_str:N #2 = true } }
-            \c_false_bool { \exp_args:Nx #1 { \token_to_str:N #2 = false } }
+            \c_true_bool { \exp_args:Ne #1 { \token_to_str:N #2 = true } }
+            \c_false_bool { \exp_args:Ne #1 { \token_to_str:N #2 = false } }
           }
           {
-            \msg_error:nnxxx { kernel } { bad-type }
+            \msg_error:nneee { kernel } { bad-type }
               { \token_to_str:N #2 } { \token_to_meaning:N #2 } { bool }
           }
       }
@@ -7254,7 +7334,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \cs_new_eq:cN { #1 _p: } \c_false_bool
       }
   }
-\str_const:Nx \c_sys_engine_str
+\str_const:Ne \c_sys_engine_str
   {
     \cs_if_exist:NT \tex_luatexversion:D { luatex }
     \cs_if_exist:NT \tex_pdftexversion:D { pdftex }
@@ -7273,7 +7353,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \group_begin:
   \cs_set_eq:NN \lua_now:e    \tex_directlua:D
-  \str_const:Nx \c_sys_engine_exec_str
+  \str_const:Ne \c_sys_engine_exec_str
     {
       \sys_if_engine_pdftex:T { pdf }
       \sys_if_engine_xetex:T  { xe  }
@@ -7291,7 +7371,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       tex
     }
 \group_end:
-\str_const:Nx \c_sys_engine_format_str
+\str_const:Ne \c_sys_engine_format_str
   {
     \cs_if_exist:NTF \fmtname
       {
@@ -7323,7 +7403,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
       { unknown }
   }
-\str_const:Nx \c_sys_engine_version_str
+\str_const:Ne \c_sys_engine_version_str
   {
     \str_case:on \c_sys_engine_str
       {
@@ -7392,7 +7472,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \tl_if_blank:nF {#1}
           { \tl_gset:Nn \g__sys_backend_tl {#1} }
         \__sys_load_backend_check:N \g__sys_backend_tl
-        \str_const:Nx \c_sys_backend_str { \g__sys_backend_tl }
+        \str_const:Ne \c_sys_backend_str { \g__sys_backend_tl }
         \__kernel_sys_configuration_load:n
           { l3backend- \c_sys_backend_str }
       }
@@ -7408,7 +7488,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
             { xetex }     { }
           }
           {
-            \msg_error:nnxx { sys } { wrong-backend }
+            \msg_error:nnee { sys } { wrong-backend }
               #1 { xetex }
             \tl_gset:Nn #1 { xetex }
           }
@@ -7427,7 +7507,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
                   { \str_if_eq_p:Vn #1 { luatex } }
                   { \str_if_eq_p:Vn #1 { pdftex } }
                   {
-                    \msg_error:nnxx { sys } { wrong-backend }
+                    \msg_error:nnee { sys } { wrong-backend }
                       #1 { \sys_if_engine_luatex:TF { luatex } { pdftex } }
                     \sys_if_engine_luatex:TF
                       { \tl_gset:Nn #1 { luatex } }
@@ -7443,7 +7523,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
                 { dvisvgm }  { }
               }
               {
-                \msg_error:nnxx { sys } { wrong-backend }
+                \msg_error:nnee { sys } { wrong-backend }
                   #1 { dvips }
                 \tl_gset:Nn #1 { dvips }
               }
@@ -7463,7 +7543,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \bool_gset_true:N \g__sys_debug_bool
   }
 \tl_new:N \l__sys_internal_tl
-\tl_const:Nx \c__sys_marker_tl { : \token_to_str:N : }
+\tl_const:Ne \c__sys_marker_tl { : \token_to_str:N : }
 \cs_new_protected:Npn \sys_get_shell:nnN #1#2#3
   {
     \sys_get_shell:nnNF {#1} {#2} #3
@@ -7479,7 +7559,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \tl_if_in:nnTF {#1} { " }
       {
-        \msg_error:nnx
+        \msg_error:nne
           { kernel } { quote-in-shell } {#1}
         \prg_return_false:
       }
@@ -7515,7 +7595,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \cs_new_protected:Npn \sys_shell_now:n #1
       { \iow_now:Nn \c__sys_shell_stream_int {#1} }
   }
-\cs_generate_variant:Nn \sys_shell_now:n { x }
+\cs_generate_variant:Nn \sys_shell_now:n { e, x }
 \sys_if_engine_luatex:TF
   {
     \cs_new_protected:Npn \sys_shell_shipout:n #1
@@ -7525,7 +7605,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \cs_new_protected:Npn \sys_shell_shipout:n #1
       { \iow_shipout:Nn \c__sys_shell_stream_int {#1} }
   }
-\cs_generate_variant:Nn \sys_shell_shipout:n { x }
+\cs_generate_variant:Nn \sys_shell_shipout:n { e , x }
 \cs_new_protected:Npn \sys_everyjob:
   {
     \tl_use:N \g__sys_everyjob_tl
@@ -7570,7 +7650,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \__sys_everyjob:n
   {
-    \str_const:Nx \c_sys_timestamp_str
+    \str_const:Ne \c_sys_timestamp_str
       {
         \cs_if_exist:NTF \tex_directlua:D
           { \tex_directlua:D { tex.print(pdf.getcreationdate()) } }
@@ -7643,7 +7723,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \tl_new:N \g__sys_finalise_tl
 \__sys_finalise:n
   {
-    \str_const:Nx \c_sys_output_str
+    \str_const:Ne \c_sys_output_str
       {
         \int_compare:nNnTF
           { \cs_if_exist_use:NF \tex_pdfoutput:D { 0 } } > { 0 }
@@ -7658,7 +7738,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \tl_new:N \g__sys_backend_tl
 \__sys_finalise:n
   {
-    \__kernel_tl_gset:Nx \g__sys_backend_tl
+    \__kernel_tl_gset:Ne \g__sys_backend_tl
       {
         \sys_if_engine_xetex:TF
           { xetex }
@@ -7756,8 +7836,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_eq:NN \clist_new:N \tl_new:N
 \cs_new_eq:NN \clist_new:c \tl_new:c
 \cs_new_protected:Npn \clist_const:Nn #1#2
-  { \tl_const:Nx #1 { \__clist_sanitize:n {#2} } }
-\cs_generate_variant:Nn \clist_const:Nn { c , Nx , cx }
+  { \tl_const:Ne #1 { \__clist_sanitize:n {#2} } }
+\cs_generate_variant:Nn \clist_const:Nn { Ne , c , ce }
+\cs_generate_variant:Nn \clist_const:Nn { Nx , cx }
 \cs_new_eq:NN \clist_clear:N  \tl_clear:N
 \cs_new_eq:NN \clist_clear:c  \tl_clear:c
 \cs_new_eq:NN \clist_gclear:N \tl_gclear:N
@@ -7775,9 +7856,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_eq:NN \clist_gset_eq:cN \tl_gset_eq:cN
 \cs_new_eq:NN \clist_gset_eq:cc \tl_gset_eq:cc
 \cs_new_protected:Npn \clist_set_from_seq:NN
-  { \__clist_set_from_seq:NNNN \clist_clear:N  \__kernel_tl_set:Nx  }
+  { \__clist_set_from_seq:NNNN \clist_clear:N  \__kernel_tl_set:Ne  }
 \cs_new_protected:Npn \clist_gset_from_seq:NN
-  { \__clist_set_from_seq:NNNN \clist_gclear:N \__kernel_tl_gset:Nx }
+  { \__clist_set_from_seq:NNNN \clist_gclear:N \__kernel_tl_gset:Ne }
 \cs_new_protected:Npn \__clist_set_from_seq:NNNN #1#2#3#4
   {
     \seq_if_empty:NTF #4
@@ -7802,9 +7883,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_generate_variant:Nn \clist_gset_from_seq:NN {     Nc }
 \cs_generate_variant:Nn \clist_gset_from_seq:NN { c , cc }
 \cs_new_protected:Npn \clist_concat:NNN
-  { \__clist_concat:NNNN \__kernel_tl_set:Nx }
+  { \__clist_concat:NNNN \__kernel_tl_set:Ne }
 \cs_new_protected:Npn \clist_gconcat:NNN
-  { \__clist_concat:NNNN \__kernel_tl_gset:Nx }
+  { \__clist_concat:NNNN \__kernel_tl_gset:Ne }
 \cs_new_protected:Npn \__clist_concat:NNNN #1#2#3#4
   {
     #1 #2
@@ -7821,11 +7902,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \prg_new_eq_conditional:NNn \clist_if_exist:c \cs_if_exist:c
   { TF , T , F , p }
 \cs_new_protected:Npn \clist_set:Nn #1#2
-  { \__kernel_tl_set:Nx #1 { \__clist_sanitize:n {#2} } }
+  { \__kernel_tl_set:Ne #1 { \__clist_sanitize:n {#2} } }
 \cs_new_protected:Npn \clist_gset:Nn #1#2
-  { \__kernel_tl_gset:Nx #1 { \__clist_sanitize:n {#2} } }
-\cs_generate_variant:Nn \clist_set:Nn  { NV , No , Nx , c , cV , co , cx }
-\cs_generate_variant:Nn \clist_gset:Nn { NV , No , Nx , c , cV , co , cx }
+  { \__kernel_tl_gset:Ne #1 { \__clist_sanitize:n {#2} } }
+\cs_generate_variant:Nn \clist_set:Nn  { NV , Ne , c , cV , ce }
+\cs_generate_variant:Nn \clist_set:Nn  { No , Nx , co , cx }
+\cs_generate_variant:Nn \clist_gset:Nn { NV , Ne , c , cV , ce }
+\cs_generate_variant:Nn \clist_gset:Nn { No , Nx , co , cx }
 \cs_new_protected:Npn \clist_put_left:Nn
   { \__clist_put_left:NNNn \clist_concat:NNN \clist_set:Nn }
 \cs_new_protected:Npn \clist_gput_left:Nn
@@ -7835,10 +7918,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     #2 \l__clist_internal_clist {#4}
     #1 #3 \l__clist_internal_clist #3
   }
-\cs_generate_variant:Nn \clist_put_left:Nn  {     NV , Nv , No , Nx }
-\cs_generate_variant:Nn \clist_put_left:Nn  { c , cV , cv , co , cx }
-\cs_generate_variant:Nn \clist_gput_left:Nn {     NV , Nv , No , Nx }
-\cs_generate_variant:Nn \clist_gput_left:Nn { c , cV , cv , co , cx }
+\cs_generate_variant:Nn \clist_put_left:Nn  { NV , Nv , Ne , c , cV , cv , ce }
+\cs_generate_variant:Nn \clist_put_left:Nn  { No , Nx , co , cx }
+\cs_generate_variant:Nn \clist_gput_left:Nn { NV , Nv , Ne , c , cV , cv , ce }
+\cs_generate_variant:Nn \clist_gput_left:Nn { No , Nx , co , cx }
 \cs_new_protected:Npn \clist_put_right:Nn
   { \__clist_put_right:NNNn \clist_concat:NNN \clist_set:Nn }
 \cs_new_protected:Npn \clist_gput_right:Nn
@@ -7848,10 +7931,14 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     #2 \l__clist_internal_clist {#4}
     #1 #3 #3 \l__clist_internal_clist
   }
-\cs_generate_variant:Nn \clist_put_right:Nn  {     NV , Nv , No , Nx }
-\cs_generate_variant:Nn \clist_put_right:Nn  { c , cV , cv , co , cx }
-\cs_generate_variant:Nn \clist_gput_right:Nn {     NV , Nv , No , Nx }
-\cs_generate_variant:Nn \clist_gput_right:Nn { c , cV , cv , co , cx }
+\cs_generate_variant:Nn \clist_put_right:Nn
+  { NV , Nv , Ne , c , cV , cv , ce }
+\cs_generate_variant:Nn \clist_put_right:Nn
+  { No , Nx , co , cx }
+\cs_generate_variant:Nn \clist_gput_right:Nn
+  { NV , Nv , Ne , c , cV , cv , ce }
+\cs_generate_variant:Nn \clist_gput_right:Nn
+  { No , Nx , co , cx }
 \cs_new_protected:Npn \clist_get:NN #1#2
   {
     \if_meaning:w #1 \c_empty_clist
@@ -7864,9 +7951,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \tl_set:Nn #3 {#1} }
 \cs_generate_variant:Nn \clist_get:NN { c }
 \cs_new_protected:Npn \clist_pop:NN
-  { \__clist_pop:NNN \__kernel_tl_set:Nx }
+  { \__clist_pop:NNN \__kernel_tl_set:Ne }
 \cs_new_protected:Npn \clist_gpop:NN
-  { \__clist_pop:NNN \__kernel_tl_gset:Nx }
+  { \__clist_pop:NNN \__kernel_tl_gset:Ne }
 \cs_new_protected:Npn \__clist_pop:NNN #1#2#3
   {
     \if_meaning:w #2 \c_empty_clist
@@ -7900,9 +7987,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \prg_generate_conditional_variant:Nnn \clist_get:NN { c } { T , F , TF }
 \prg_new_protected_conditional:Npnn \clist_pop:NN #1#2 { T , F , TF }
-  { \__clist_pop_TF:NNN \__kernel_tl_set:Nx #1 #2 }
+  { \__clist_pop_TF:NNN \__kernel_tl_set:Ne #1 #2 }
 \prg_new_protected_conditional:Npnn \clist_gpop:NN #1#2 { T , F , TF }
-  { \__clist_pop_TF:NNN \__kernel_tl_gset:Nx #1 #2 }
+  { \__clist_pop_TF:NNN \__kernel_tl_gset:Ne #1 #2 }
 \cs_new_protected:Npn \__clist_pop_TF:NNN #1#2#3
   {
     \if_meaning:w #2 \c_empty_clist
@@ -7915,21 +8002,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \prg_generate_conditional_variant:Nnn \clist_pop:NN { c } { T , F , TF }
 \prg_generate_conditional_variant:Nnn \clist_gpop:NN { c } { T , F , TF }
 \cs_new_eq:NN \clist_push:Nn  \clist_put_left:Nn
-\cs_new_eq:NN \clist_push:NV  \clist_put_left:NV
-\cs_new_eq:NN \clist_push:No  \clist_put_left:No
-\cs_new_eq:NN \clist_push:Nx  \clist_put_left:Nx
-\cs_new_eq:NN \clist_push:cn  \clist_put_left:cn
-\cs_new_eq:NN \clist_push:cV  \clist_put_left:cV
-\cs_new_eq:NN \clist_push:co  \clist_put_left:co
-\cs_new_eq:NN \clist_push:cx  \clist_put_left:cx
+\cs_generate_variant:Nn \clist_push:Nn { NV , No , Nx , c , cV , co , cx }
 \cs_new_eq:NN \clist_gpush:Nn \clist_gput_left:Nn
-\cs_new_eq:NN \clist_gpush:NV \clist_gput_left:NV
-\cs_new_eq:NN \clist_gpush:No \clist_gput_left:No
-\cs_new_eq:NN \clist_gpush:Nx \clist_gput_left:Nx
-\cs_new_eq:NN \clist_gpush:cn \clist_gput_left:cn
-\cs_new_eq:NN \clist_gpush:cV \clist_gput_left:cV
-\cs_new_eq:NN \clist_gpush:co \clist_gput_left:co
-\cs_new_eq:NN \clist_gpush:cx \clist_gput_left:cx
+\cs_generate_variant:Nn \clist_gpush:Nn { NV , No , Nx , c , cV , co , cx }
 \clist_new:N \l__clist_internal_remove_clist
 \seq_new:N \l__clist_internal_remove_seq
 \cs_new_protected:Npn \clist_remove_duplicates:N
@@ -7943,7 +8018,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       {
         \clist_if_in:NnF \l__clist_internal_remove_clist {##1}
           {
-            \tl_put_right:Nx \l__clist_internal_remove_clist
+            \tl_put_right:Ne \l__clist_internal_remove_clist
               {
                 \clist_if_empty:NF \l__clist_internal_remove_clist { , }
                 \__clist_if_wrap:nTF {##1} { \exp_not:n { {##1} } } { \exp_not:n {##1} }
@@ -7955,9 +8030,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_generate_variant:Nn \clist_remove_duplicates:N  { c }
 \cs_generate_variant:Nn \clist_gremove_duplicates:N { c }
 \cs_new_protected:Npn \clist_remove_all:Nn
-  { \__clist_remove_all:NNNn \clist_set_from_seq:NN \__kernel_tl_set:Nx }
+  { \__clist_remove_all:NNNn \clist_set_from_seq:NN \__kernel_tl_set:Ne }
 \cs_new_protected:Npn \clist_gremove_all:Nn
-  { \__clist_remove_all:NNNn \clist_gset_from_seq:NN \__kernel_tl_gset:Nx }
+  { \__clist_remove_all:NNNn \clist_gset_from_seq:NN \__kernel_tl_gset:Ne }
 \cs_new_protected:Npn \__clist_remove_all:NNNn #1#2#3#4
   {
     \__clist_if_wrap:nTF {#4}
@@ -7994,9 +8069,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_generate_variant:Nn \clist_remove_all:Nn  { c , NV , cV }
 \cs_generate_variant:Nn \clist_gremove_all:Nn { c , NV , cV }
 \cs_new_protected:Npn \clist_reverse:N #1
-  { \__kernel_tl_set:Nx #1 { \exp_args:No \clist_reverse:n {#1} } }
+  { \__kernel_tl_set:Ne #1 { \exp_args:No \clist_reverse:n {#1} } }
 \cs_new_protected:Npn \clist_greverse:N #1
-  { \__kernel_tl_gset:Nx #1 { \exp_args:No \clist_reverse:n {#1} } }
+  { \__kernel_tl_gset:Ne #1 { \exp_args:No \clist_reverse:n {#1} } }
 \cs_generate_variant:Nn \clist_reverse:N { c }
 \cs_generate_variant:Nn \clist_greverse:N { c }
 \cs_new:Npn \clist_reverse:n #1
@@ -8043,7 +8118,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \__clist_if_wrap:nTF {#2}
       {
-        \cs_set:Npx \__clist_tmp:w ##1
+        \cs_set:Npe \__clist_tmp:w ##1
           {
             \exp_not:N \tl_if_eq:nnT {##1}
             \exp_not:n
@@ -8097,6 +8172,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \s__clist_stop \clist_map_break: ,
     \prg_break_point:Nn \clist_map_break: { }
   }
+\cs_generate_variant:Nn \clist_map_function:nN { e }
 \cs_new:Npn \__clist_map_function_n:Nn #1 #2
   {
     \__clist_use_none_delimit_by_s_stop:w #2 \s__clist_stop
@@ -8211,6 +8287,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
   }
 \exp_args:No \__clist_tmp:w \c_space_tl
+\cs_generate_variant:Nn \clist_count:n { e }
 \cs_new:Npn \clist_use:Nnnn #1#2#3#4
   {
     \clist_if_exist:NTF #1
@@ -8316,6 +8393,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       {#1}
       \__clist_item_n:nw
   }
+\cs_generate_variant:Nn \clist_item:nn { e }
 \cs_new:Npn \__clist_item_n:nw #1
   { \__clist_item_n_loop:nw {#1} \prg_do_nothing: }
 \cs_new:Npn \__clist_item_n_loop:nw #1 #2,
@@ -8349,9 +8427,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { \clist_item:Nn #1 { \int_rand:nn { 1 } { \clist_count:N #1 } } }
   }
 \cs_generate_variant:Nn \clist_rand_item:N { c }
-\cs_new_protected:Npn \clist_show:N { \__clist_show:NN \msg_show:nnxxxx }
+\cs_new_protected:Npn \clist_show:N { \__clist_show:NN \msg_show:nneeee }
 \cs_generate_variant:Nn \clist_show:N { c }
-\cs_new_protected:Npn \clist_log:N { \__clist_show:NN \msg_log:nnxxxx }
+\cs_new_protected:Npn \clist_log:N { \__clist_show:NN \msg_log:nneeee }
 \cs_generate_variant:Nn \clist_log:N { c }
 \cs_new_protected:Npn \__clist_show:NN #1#2
   {
@@ -8366,13 +8444,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
               { } { }
           }
           {
-            \msg_error:nnxx { clist } { non-clist }
+            \msg_error:nnee { clist } { non-clist }
               { \token_to_str:N #2 } { \tl_to_str:N #2 }
           }
       }
   }
-\cs_new_protected:Npn \clist_show:n { \__clist_show:Nn \msg_show:nnxxxx }
-\cs_new_protected:Npn \clist_log:n { \__clist_show:Nn \msg_log:nnxxxx }
+\cs_new_protected:Npn \clist_show:n { \__clist_show:Nn \msg_show:nneeee }
+\cs_new_protected:Npn \clist_log:n { \__clist_show:Nn \msg_log:nneeee }
 \cs_new_protected:Npn \__clist_show:Nn #1#2
   {
     #1 { clist } { show }
@@ -8496,7 +8574,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
             \char_set_lccode:nn { `\^^@ } { ##1 }
           \tex_lowercase:D { \group_end: #2 ^^@ }
         }
-      \cs_new_protected:cpx { #1 :NN } ##1
+      \cs_new_protected:cpe { #1 :NN } ##1
         { \exp_not:c { #1 : nN } { `##1 } }
     }
   \__char_tmp:nN { char_set_active_eq }  \cs_set_eq:NN
@@ -8563,7 +8641,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \char_set_catcode_math_superscript:n { 0 }
     \tl_put_right:Nn \l__char_tmp_tl { ^^@ \exp_not:N \or: }
     \char_set_catcode_parameter:n { 0 }
-    \tl_put_right:Nn \l__char_tmp_tl { ^^@^^@ \exp_not:N \or: }
+    \tl_put_right:Nn \l__char_tmp_tl { ^^@ \exp_not:N \or: }
     \tl_put_right:Nn \l__char_tmp_tl { { \if_false: } \fi: \exp_not:N \or: }
     \char_set_catcode_alignment:n { 0 }
     \tl_put_right:Nn \l__char_tmp_tl { ^^@ \exp_not:N \or: }
@@ -8577,9 +8655,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         {
           \char_set_lccode:nn { 0 } {#1}
           \char_set_lccode:nn { 32 } {#1}
-          \exp_args:Nx \tex_lowercase:D
+          \exp_args:Ne \tex_lowercase:D
             {
-              \tl_const:Nx
+              \tl_const:Ne
                 \exp_not:c { c__char_ \__char_int_to_roman:w #1 _tl }
                 { \exp_not:o \l__char_tmp_tl }
             }
@@ -8725,7 +8803,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   \char_set_lccode:nn { `* } { `\ }
   \tex_lowercase:D { \tl_const:Nn \c_catcode_active_space_tl { * } }
 \group_end:
-\tl_const:Nx \c_catcode_other_space_tl { \char_generate:nn { `\  } { 12 } }
+\tl_const:Ne \c_catcode_other_space_tl { \char_generate:nn { `\  } { 12 } }
 \scan_new:N \s__token_mark
 \scan_new:N \s__token_stop
 \group_begin:
@@ -8821,17 +8899,17 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \if_charcode:w \exp_not:N #1 \exp_not:N #2
       \prg_return_true: \else: \prg_return_false: \fi:
   }
-\use:x
+\use:e
   {
-    \prg_new_conditional:Npnn \exp_not:N \token_if_macro:N ##1
+    \prg_new_conditional:Npnn \exp_not:N \token_if_macro:N #1
       { p , T ,  F , TF }
       {
         \exp_not:N \exp_after:wN \exp_not:N \__token_if_macro_p:w
-        \exp_not:N \token_to_meaning:N ##1 \tl_to_str:n { ma : }
+        \exp_not:N \token_to_meaning:N #1 \tl_to_str:n { ma : }
           \s__token_stop
       }
     \cs_new:Npn \exp_not:N  \__token_if_macro_p:w
-      ##1 \tl_to_str:n { ma } ##2 \c_colon_str ##3 \s__token_stop
+      #1 \tl_to_str:n { ma } #2 \c_colon_str #3 \s__token_stop
   }
       {
         \str_if_eq:nnTF { #2 } { cro }
@@ -8858,11 +8936,11 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \group_begin:
 \cs_set_protected:Npn \__token_tmp:w #1
   {
-    \use:x
+    \use:e
       {
         \cs_new:Npn \exp_not:c { __token_delimit_by_ #1 :w }
-            ####1 \tl_to_str:n {#1} ####2 \s__token_stop
-          { ####1 \tl_to_str:n {#1} }
+            ##1 \tl_to_str:n {#1} ##2 \s__token_stop
+          { ##1 \tl_to_str:n {#1} }
       }
   }
 \__token_tmp:w { char" }
@@ -8877,17 +8955,17 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \group_begin:
 \cs_set_protected:Npn \__token_tmp:w #1#2#3
   {
-    \use:x
+    \use:e
       {
-        \prg_new_conditional:Npnn \exp_not:c { token_if_ #1 :N } ####1
+        \prg_new_conditional:Npnn \exp_not:c { token_if_ #1 :N } ##1
           { p , T ,  F , TF }
           {
             \cs_if_exist:cT { tex_ #2 :D }
               {
-                \exp_not:N \if_meaning:w ####1 \exp_not:c { tex_ #2 :D }
+                \exp_not:N \if_meaning:w ##1 \exp_not:c { tex_ #2 :D }
                 \exp_not:N \prg_return_false:
                 \exp_not:N \else:
-                \exp_not:N \if_meaning:w ####1 \exp_not:c { tex_ #2 def:D }
+                \exp_not:N \if_meaning:w ##1 \exp_not:c { tex_ #2 def:D }
                 \exp_not:N \prg_return_false:
                 \exp_not:N \else:
               }
@@ -8895,7 +8973,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
               {
                 \exp_not:N \exp_after:wN
                 \exp_not:c { __token_delimit_by_ #2 :w }
-                \exp_not:N \token_to_meaning:N ####1
+                \exp_not:N \token_to_meaning:N ##1
                 ? \tl_to_str:n {#2} \s__token_stop
               }
               { \exp_not:n {#3} }
@@ -8932,26 +9010,26 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
   {
     \tex_chardef:D \c__token_A_int = `A ~ %
-    \use:x
+    \use:e
       {
-        \prg_new_conditional:Npnn \exp_not:N \token_if_primitive:N ##1
+        \prg_new_conditional:Npnn \exp_not:N \token_if_primitive:N #1
           { p , T , F , TF }
           {
-            \exp_not:N \token_if_macro:NTF ##1
+            \exp_not:N \token_if_macro:NTF #1
               \exp_not:N \prg_return_false:
               {
                 \exp_not:N \exp_after:wN \exp_not:N \__token_if_primitive:NNw
-                \exp_not:N \token_to_meaning:N ##1
-                  \tl_to_str:n { : : : } \s__token_stop ##1
+                \exp_not:N \token_to_meaning:N #1
+                  \tl_to_str:n { : : : } \s__token_stop #1
               }
           }
         \cs_new:Npn \exp_not:N \__token_if_primitive:NNw
-          ##1##2 ##3 \c_colon_str ##4 \s__token_stop
+          #1#2 #3 \c_colon_str #4 \s__token_stop
           {
             \exp_not:N \tl_if_empty:oTF
-              { \exp_not:N \__token_if_primitive_space:w ##3 ~ }
+              { \exp_not:N \__token_if_primitive_space:w #3 ~ }
               {
-                \exp_not:N \__token_if_primitive_loop:N ##3
+                \exp_not:N \__token_if_primitive_loop:N #3
                   \c_colon_str \s__token_stop
               }
               { \exp_not:N \__token_if_primitive_nullfont:N }
@@ -9054,7 +9132,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \peek_remove_spaces:n #1
   {
-    \cs_set:Npx \__peek_false:w { \exp_not:n {#1} }
+    \cs_set:Npe \__peek_false:w { \exp_not:n {#1} }
     \group_align_safe_begin:
     \cs_set:Npn \__peek_true_aux:w { \peek_after:Nw \__peek_remove_spaces: }
     \__peek_true_aux:w
@@ -9071,7 +9149,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \peek_remove_filler:n #1
   {
     \cs_set:Npn \__peek_true_aux:w { \__peek_remove_filler:w }
-    \cs_set:Npx \__peek_false:w
+    \cs_set:Npe \__peek_false:w
       {
         \exp_not:N \group_align_safe_end:
         \exp_not:n {#1}
@@ -9111,13 +9189,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \group_align_safe_begin:
     \cs_set_eq:NN \l__peek_search_token #3
     \tl_set:Nn \l__peek_search_tl {#3}
-    \cs_set:Npx \__peek_true_aux:w
+    \cs_set:Npe \__peek_true_aux:w
       {
         \exp_not:N \group_align_safe_end:
         \exp_not:n {#4}
       }
     \cs_set_eq:NN \__peek_true:w #1
-    \cs_set:Npx \__peek_false:w
+    \cs_set:Npe \__peek_false:w
       {
         \exp_not:N \group_align_safe_end:
         \exp_not:n {#5}
@@ -9183,7 +9261,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       {
         \tl_map_inline:nn { { TF } { T } { F } }
           {
-            \cs_new_protected:cpx { peek_ #1 ##1 :N ####1 }
+            \cs_new_protected:cpe { peek_ #1 ##1 :N ####1 }
               {
                 \exp_not:c { __peek_token ##1 _generic:NN ####1 }
                 \exp_not:c { __peek_execute_branches_ #1 : }
@@ -9302,7 +9380,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \prop_const_from_keyval:Nn #1#2
   {
     \prop_set_from_keyval:Nn \l__prop_internal_prop {#2}
-    \tl_const:Nx #1 { \exp_not:o \l__prop_internal_prop }
+    \tl_const:Ne #1 { \exp_not:o \l__prop_internal_prop }
     \prop_clear:N \l__prop_internal_prop
   }
 \cs_generate_variant:Nn \prop_const_from_keyval:Nn { c }
@@ -9353,18 +9431,17 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { \tl_gset:Nn #1 { ##1 ##3 } }
       { }
   }
-\cs_generate_variant:Nn \prop_remove:Nn  {     NV }
-\cs_generate_variant:Nn \prop_remove:Nn  { c , cV }
-\cs_generate_variant:Nn \prop_gremove:Nn {     NV }
-\cs_generate_variant:Nn \prop_gremove:Nn { c , cV }
+\cs_generate_variant:Nn \prop_remove:Nn  { NV , Ne , c , cV , ce }
+\cs_generate_variant:Nn \prop_gremove:Nn { NV , Ne , c , cV , ce }
 \cs_new_protected:Npn \prop_get:NnN #1#2#3
   {
     \__prop_split:NnTF #1 {#2}
       { \tl_set:Nn #3 {##2} }
       { \tl_set:Nn #3 { \q_no_value } }
   }
-\cs_generate_variant:Nn \prop_get:NnN {     NV , Nv , No , Nx }
-\cs_generate_variant:Nn \prop_get:NnN { c , cV , cv , co , cx , cnc }
+\cs_generate_variant:Nn \prop_get:NnN { NV , Nv , Ne , c , cV , cv , ce }
+\cs_generate_variant:Nn \prop_get:NnN { No , Nx , co , cx }
+\cs_generate_variant:Nn \prop_get:NnN { cnc }
 \cs_new_protected:Npn \prop_pop:NnN #1#2#3
   {
     \__prop_split:NnTF #1 {#2}
@@ -9383,10 +9460,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
       { \tl_set:Nn #3 { \q_no_value } }
   }
-\cs_generate_variant:Nn \prop_pop:NnN  {     No }
-\cs_generate_variant:Nn \prop_pop:NnN  { c , co }
-\cs_generate_variant:Nn \prop_gpop:NnN {     No }
-\cs_generate_variant:Nn \prop_gpop:NnN { c , co }
+\cs_generate_variant:Nn \prop_pop:NnN  {     NV , No }
+\cs_generate_variant:Nn \prop_pop:NnN  { c , cV , co }
+\cs_generate_variant:Nn \prop_gpop:NnN {     NV , No }
+\cs_generate_variant:Nn \prop_gpop:NnN { c , cV , co }
 \cs_new:Npn \prop_item:Nn #1#2
   {
     \exp_args:NNo \prop_map_tokens:Nn #1
@@ -9446,10 +9523,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
       { \prg_return_false: }
   }
-\prg_generate_conditional_variant:Nnn \prop_pop:NnN { c } { T , F , TF }
-\prg_generate_conditional_variant:Nnn \prop_gpop:NnN { c } { T , F , TF }
-\cs_new_protected:Npn \prop_put:Nnn  { \__prop_put:NNnn \__kernel_tl_set:Nx }
-\cs_new_protected:Npn \prop_gput:Nnn { \__prop_put:NNnn \__kernel_tl_gset:Nx }
+\prg_generate_conditional_variant:Nnn \prop_pop:NnN  { NV , c , cV } { T , F , TF }
+\prg_generate_conditional_variant:Nnn \prop_gpop:NnN { NV , c , cV } { T , F , TF }
+\cs_new_protected:Npn \prop_put:Nnn  { \__prop_put:NNnn \__kernel_tl_set:Ne }
+\cs_new_protected:Npn \prop_gput:Nnn { \__prop_put:NNnn \__kernel_tl_gset:Ne }
 \cs_new_protected:Npn \__prop_put:NNnn #1#2#3#4
   {
     \tl_set:Nn \l__prop_internal_tl
@@ -9462,17 +9539,37 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { #1 #2 { \exp_not:o {#2} \l__prop_internal_tl } }
   }
 \cs_generate_variant:Nn \prop_put:Nnn
-  {     NnV , Nno , Nne , Nnx , NV , NVV , NVx , Nvx , No , Nx , NxV , Noo , Nxx }
+  {
+         NnV , Nnv , Nne , NV , NVV , NVv , NVe ,
+    Nv , NvV , Nvv , Nve , Ne , NeV , Nev , Nee
+  }
+\cs_generate_variant:Nn \prop_put:Nnn
+  { Nno , No , Noo , Nnx , NVx , NxV , Nxx }
+\cs_generate_variant:Nn \prop_put:Nnn
+  {
+    c  , cnV , cnv , cne , cV , cVV , cVv , cVe ,
+    cv , cvV , cvv , cve , ce , ceV , cev , cee
+  }
 \cs_generate_variant:Nn \prop_put:Nnn
-  { c , cnV , cno , cne , cnx , cV , cVV , cVx , cvx , co , cx , cxV , coo , cxx }
+  { cno , co , coo , cnx , cVx , cxV , cxx }
+\cs_generate_variant:Nn \prop_gput:Nnn
+  {
+         NnV , Nnv , Nne , NV , NVV , NVv , NVe ,
+    Nv , NvV , Nvv , Nve , Ne , NeV , Nev , Nee
+  }
 \cs_generate_variant:Nn \prop_gput:Nnn
-  {     NnV , Nno , Nne , Nnx , NV , NVV , NVx , Nvx , No , Nx , NxV , Noo , Nxx }
+  { Nno , No , Noo , Nnx , NVx , NxV , Nxx }
 \cs_generate_variant:Nn \prop_gput:Nnn
-  { c , cnV , cno , cne , cnx , cV , cVV , cVx , cvx , co , cx , cxV , coo , cxx }
+  {
+    c  , cnV , cnv , cne , cV , cVV , cVv , cVe ,
+    cv , cvV , cvv , cve , ce , ceV , cev , cee
+  }
+\cs_generate_variant:Nn \prop_gput:Nnn
+  { cno , co , coo , cnx , cVx , cxV , cxx }
 \cs_new_protected:Npn \prop_put_if_new:Nnn
-  { \__prop_put_if_new:NNnn \__kernel_tl_set:Nx }
+  { \__prop_put_if_new:NNnn \__kernel_tl_set:Ne }
 \cs_new_protected:Npn \prop_gput_if_new:Nnn
-  { \__prop_put_if_new:NNnn \__kernel_tl_gset:Nx }
+  { \__prop_put_if_new:NNnn \__kernel_tl_gset:Ne }
 \cs_new_protected:Npn \__prop_put_if_new:NNnn #1#2#3#4
   {
     \tl_set:Nn \l__prop_internal_tl
@@ -9484,8 +9581,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { }
       { #1 #2 { \exp_not:o {#2} \l__prop_internal_tl } }
   }
-\cs_generate_variant:Nn \prop_put_if_new:Nnn  { c }
-\cs_generate_variant:Nn \prop_gput_if_new:Nnn { c }
+\cs_generate_variant:Nn \prop_put_if_new:Nnn
+  { NnV , NV , cnV , cV }
+\cs_generate_variant:Nn \prop_gput_if_new:Nnn
+  { NnV , NV , cnV , cV }
 \prg_new_eq_conditional:NNn \prop_if_exist:N \cs_if_exist:N
   { TF , T , F , p }
 \prg_new_eq_conditional:NNn \prop_if_exist:c \cs_if_exist:c
@@ -9509,7 +9608,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { \prop_map_break:n { \use_i:nn \prg_return_true: } }
   }
 \prg_generate_conditional_variant:Nnn \prop_if_in:Nn
-  { NV , No , c , cV , co } { p , T , F , TF }
+  { NV , Ne , No , c , cV , ce , co } { p , T , F , TF }
 \prg_new_protected_conditional:Npnn \prop_get:NnN #1#2#3 { T , F , TF }
   {
     \__prop_split:NnTF #1 {#2}
@@ -9520,7 +9619,11 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { \prg_return_false: }
   }
 \prg_generate_conditional_variant:Nnn \prop_get:NnN
-  { NV , Nv , No , Nx , c , cV , cv , co , cx , cnc } { T , F , TF }
+  { NV , Nv , Ne , c , cV , cv , ce } { T , F , TF }
+\prg_generate_conditional_variant:Nnn \prop_get:NnN
+  { No , Nx , co , cx } { T , F , TF }
+\prg_generate_conditional_variant:Nnn \prop_get:NnN
+  { cnc } { T , F , TF }
 \cs_new:Npn \prop_map_function:NN #1#2
   {
     \exp_after:wN \use_i_ii:nnn
@@ -9588,9 +9691,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \prg_map_break:Nn \prop_map_break: { } }
 \cs_new:Npn \prop_map_break:n
   { \prg_map_break:Nn \prop_map_break: }
-\cs_new_protected:Npn \prop_show:N { \__prop_show:NN \msg_show:nnxxxx }
+\cs_new_protected:Npn \prop_show:N { \__prop_show:NN \msg_show:nneeee }
 \cs_generate_variant:Nn \prop_show:N { c }
-\cs_new_protected:Npn \prop_log:N { \__prop_show:NN \msg_log:nnxxxx }
+\cs_new_protected:Npn \prop_log:N { \__prop_show:NN \msg_log:nneeee }
 \cs_generate_variant:Nn \prop_log:N { c }
 \cs_new_protected:Npn \__prop_show:NN #1#2
   {
@@ -9631,7 +9734,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \msg_if_exist:nnT {#1} {#2}
       {
-        \msg_error:nnxx { msg } { already-defined }
+        \msg_error:nnnn { msg } { already-defined }
           {#1} {#2}
       }
   }
@@ -9640,10 +9743,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \__msg_chk_free:nn {#1} {#2}
     \msg_gset:nnnn {#1} {#2}
   }
-\cs_generate_variant:Nn \msg_new:nnnn { nnxx }
+\cs_generate_variant:Nn \msg_new:nnnn { nnee , nnxx }
 \cs_new_protected:Npn \msg_new:nnn #1#2#3
   { \msg_new:nnnn {#1} {#2} {#3} { } }
-\cs_generate_variant:Nn \msg_new:nnn { nnx }
+\cs_generate_variant:Nn \msg_new:nnn { nne , nnx }
 \cs_new_protected:Npn \msg_set:nnnn #1#2#3#4
   {
     \cs_set:cpn { \c__msg_text_prefix_tl #1 / #2 }
@@ -9703,8 +9806,8 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__msg_interrupt:NnnnN #1#2#3#4#5
   {
-    \str_set:Nx \l__msg_text_str { #1 {#2} }
-    \str_set:Nx \l__msg_name_str { \msg_module_name:n {#2} }
+    \str_set:Ne \l__msg_text_str { #1 {#2} }
+    \str_set:Ne \l__msg_name_str { \msg_module_name:n {#2} }
     \cs_if_eq:cNTF
       { \c__msg_more_text_prefix_tl #2 / #3 }
       \__msg_no_more_text:nnnn
@@ -9735,7 +9838,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \iow_wrap:nnnN { \\ #3 } { } { } \__msg_interrupt_more_text:n
     \group_begin:
       \int_sub:Nn \l_iow_line_count_int { 2 }
-      \iow_wrap:nxnN { \l__msg_text_str : ~ #1 }
+      \iow_wrap:nenN { \l__msg_text_str : ~ #1 }
         {
           ( \l__msg_name_str )
           \prg_replicate:nn
@@ -9756,7 +9859,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \tl_set:Nn \l__msg_internal_tl {#1}
   }
 \cs_new_protected:Npn \__msg_interrupt_more_text:n #1
-  { \exp_args:Nx \tex_errhelp:D { #1 \iow_newline: } }
+  { \exp_args:Ne \tex_errhelp:D { #1 \iow_newline: } }
 \group_begin:
   \char_set_lccode:nn { 38 } { 32 } % &
   \char_set_lccode:nn { 46 } { 32 } % .
@@ -9846,39 +9949,28 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           ##1##2##3##4##5##6 {#2}
       \cs_new_protected:cpn { msg_ #1 :nnnnnn } ##1##2##3##4##5##6
         {
-          \use:x
+          \use:e
             {
               \exp_not:n { \__msg_use:nnnnnnn {#1} {##1} {##2} }
                 { \tl_to_str:n {##3} } { \tl_to_str:n {##4} }
                 { \tl_to_str:n {##5} } { \tl_to_str:n {##6} }
             }
         }
-      \cs_new_protected:cpx { msg_ #1 :nnnnn } ##1##2##3##4##5
+      \cs_new_protected:cpe { msg_ #1 :nnnnn } ##1##2##3##4##5
         { \exp_not:c { msg_ #1 :nnnnnn } {##1} {##2} {##3} {##4} {##5} { } }
-      \cs_new_protected:cpx { msg_ #1 :nnnn } ##1##2##3##4
+      \cs_new_protected:cpe { msg_ #1 :nnnn } ##1##2##3##4
         { \exp_not:c { msg_ #1 :nnnnnn } {##1} {##2} {##3} {##4} { } { } }
-      \cs_new_protected:cpx { msg_ #1 :nnn } ##1##2##3
+      \cs_new_protected:cpe { msg_ #1 :nnn } ##1##2##3
         { \exp_not:c { msg_ #1 :nnnnnn } {##1} {##2} {##3} { } { } { } }
-      \cs_new_protected:cpx { msg_ #1 :nn } ##1##2
+      \cs_new_protected:cpe { msg_ #1 :nn } ##1##2
         { \exp_not:c { msg_ #1 :nnnnnn } {##1} {##2} { } { } { } { } }
-      \cs_generate_variant:cn { msg_ #1 :nnn } { nnV }
-      \cs_generate_variant:cn { msg_ #1 :nnnn } { nnVV , nnVn , nnnV , nnnx }
-      \cs_generate_variant:cn { msg_ #1 :nnnnn } { nnnxx }
-      \cs_new_protected:cpx { msg_ #1 :nnxxxx } ##1##2##3##4##5##6
-        {
-          \use:x
-            {
-              \exp_not:N \exp_not:n
-                { \exp_not:c { msg_ #1 :nnnnnn } {##1} {##2} }
-                {##3} {##4} {##5} {##6}
-            }
-        }
-      \cs_new_protected:cpx { msg_ #1 :nnxxx } ##1##2##3##4##5
-        { \exp_not:c { msg_ #1 :nnxxxx } {##1} {##2} {##3} {##4} {##5} { } }
-      \cs_new_protected:cpx { msg_ #1 :nnxx } ##1##2##3##4
-        { \exp_not:c { msg_ #1 :nnxxxx } {##1} {##2} {##3} {##4} { } { } }
-      \cs_new_protected:cpx { msg_ #1 :nnx } ##1##2##3
-        { \exp_not:c { msg_ #1 :nnxxxx } {##1} {##2} {##3} { } { } { } }
+      \cs_generate_variant:cn { msg_ #1 :nnn }
+        { nnV , nne , nnx }
+      \cs_generate_variant:cn { msg_ #1 :nnnn }
+        { nnVV , nnVn , nnnV , nnne , nnnx , nnee , nnxx }
+      \cs_generate_variant:cn { msg_ #1 :nnnnn }
+        { nnnee , nnnxx , nneee , nnxxx }
+       \cs_generate_variant:cn { msg_ #1 :nnnnnn } { nneeee , nnxxxx }
     }
   \__msg_class_new:nn { fatal }
     {
@@ -9901,8 +9993,8 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \c__msg_critical_text_tl
       \tex_endinput:D
     }
-  \cs_undefine:N \msg_error:nnxx
-  \cs_undefine:N \msg_error:nnx
+  \cs_undefine:N \msg_error:nnee
+  \cs_undefine:N \msg_error:nne
   \cs_undefine:N \msg_error:nn
   \__msg_class_new:nn { error }
     {
@@ -9913,10 +10005,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     }
   \cs_new_protected:Npn \__msg_info_aux:NNnnnnnn #1#2#3#4#5#6#7#8
     {
-      \str_set:Nx \l__msg_text_str { #2 {#3} }
-      \str_set:Nx \l__msg_name_str { \msg_module_name:n {#3} }
+      \str_set:Ne \l__msg_text_str { #2 {#3} }
+      \str_set:Ne \l__msg_name_str { \msg_module_name:n {#3} }
       #1 { }
-      \iow_wrap:nxnN
+      \iow_wrap:nenN
         {
           \l__msg_text_str : ~
           \use:c { \c__msg_text_prefix_tl #3 / #4 } {#5} {#6} {#7} {#8}
@@ -9996,18 +10088,18 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         }
     }
 \group_end:
-\cs_new:Npx \msg_show_item:n #1
+\cs_new:Npe \msg_show_item:n #1
   { ^^J > ~ \c_space_tl \exp_not:N \tl_to_str:n { {#1} } }
-\cs_new:Npx \msg_show_item_unbraced:n #1
+\cs_new:Npe \msg_show_item_unbraced:n #1
   { ^^J > ~ \c_space_tl \exp_not:N \tl_to_str:n {#1} }
-\cs_new:Npx \msg_show_item:nn #1#2
+\cs_new:Npe \msg_show_item:nn #1#2
   {
     ^^J > \use:nn { ~ } { ~ }
     \exp_not:N \tl_to_str:n { {#1} }
     \use:nn { ~ } { ~ } => \use:nn { ~ } { ~ }
     \exp_not:N \tl_to_str:n { {#2} }
   }
-\cs_new:Npx \msg_show_item_unbraced:nn #1#2
+\cs_new:Npe \msg_show_item_unbraced:nn #1#2
   {
     ^^J > \use:nn { ~ } { ~ }
     \exp_not:N \tl_to_str:n {#1}
@@ -10017,7 +10109,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new:Npn \__msg_class_chk_exist:nT #1
   {
     \cs_if_free:cTF { __msg_ #1 _code:nnnnnn }
-      { \msg_error:nnx { msg } { class-unknown } {#1} }
+      { \msg_error:nnn { msg } { class-unknown } {#1} }
   }
 \tl_new:N \l__msg_class_tl
 \tl_new:N \l__msg_current_class_tl
@@ -10032,7 +10124,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \__msg_class_chk_exist:nT {#1}
           {
             \tl_set:Nn \l__msg_current_class_tl {#1}
-            \cs_set_protected:Npx \__msg_use_code:
+            \cs_set_protected:Npe \__msg_use_code:
               {
                 \exp_not:n
                   {
@@ -10043,7 +10135,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
             \__msg_use_redirect_name:n { #2 / #3 }
           }
       }
-      { \msg_error:nnxx { msg } { unknown } {#2} {#3} }
+      { \msg_error:nnnn { msg } { unknown } {#2} {#3} }
     \cs_if_exist_use:N \conditionally@traceon
   }
 \cs_new_protected:Npn \__msg_use_code: { }
@@ -10131,7 +10223,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
             \tl_if_eq:NNTF \l__msg_class_tl \l__msg_current_class_tl
               {
                 \prop_put:cnn { l__msg_redirect_ #2 _prop } {#3} {#2}
-                \msg_warning:nnxxxx
+                \msg_warning:nneeee
                   { msg } { redirect-loop }
                   { \seq_item:Nn \l__msg_class_loop_seq { 1 } }
                   { \seq_item:Nn \l__msg_class_loop_seq { 2 } }
@@ -10157,18 +10249,18 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \msg_new:nnnn { LaTeX / #1 } }
 \cs_new_protected:Npn \__kernel_msg_new:nnn #1
   { \msg_new:nnn { LaTeX / #1 } }
-\cs_new_protected:Npn \__kernel_msg_info:nnxx #1
-  { \msg_info:nnxx { LaTeX / #1 } }
-\cs_new_protected:Npn \__kernel_msg_warning:nnx #1
-  { \msg_warning:nnx { LaTeX / #1 } }
-\cs_new_protected:Npn \__kernel_msg_warning:nnxx #1
-  { \msg_warning:nnxx { LaTeX / #1 } }
-\cs_new_protected:Npn \__kernel_msg_error:nnx #1
-  { \msg_error:nnx { LaTeX / #1 } }
-\cs_new_protected:Npn \__kernel_msg_error:nnxx #1
-  { \msg_error:nnxx { LaTeX / #1 } }
-\cs_new_protected:Npn \__kernel_msg_error:nnxxx #1
-  { \msg_error:nnxxx { LaTeX / #1 } }
+\cs_new_protected:Npn \__kernel_msg_info:nnee #1
+  { \msg_info:nnee { LaTeX / #1 } }
+\cs_new_protected:Npn \__kernel_msg_warning:nne #1
+  { \msg_warning:nne { LaTeX / #1 } }
+\cs_new_protected:Npn \__kernel_msg_warning:nnee #1
+  { \msg_warning:nnee { LaTeX / #1 } }
+\cs_new_protected:Npn \__kernel_msg_error:nne #1
+  { \msg_error:nne { LaTeX / #1 } }
+\cs_new_protected:Npn \__kernel_msg_error:nnee #1
+  { \msg_error:nnee { LaTeX / #1 } }
+\cs_new_protected:Npn \__kernel_msg_error:nneee #1
+  { \msg_error:nneee { LaTeX / #1 } }
 \cs_new:Npn \__kernel_msg_expandable_error:nnn #1
   { \msg_expandable_error:nnn { LaTeX / #1 } }
 \cs_new:Npn \__kernel_msg_expandable_error:nnf #1
@@ -10608,12 +10700,12 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { \__ior_open_stream:Nn #1 {#2} }
       {
         \__ior_new:N #1
-        \__kernel_tl_set:Nx \l__ior_stream_tl { \int_eval:n {#1} }
+        \__kernel_tl_set:Ne \l__ior_stream_tl { \int_eval:n {#1} }
         \__ior_open_stream:Nn #1 {#2}
       }
   }
 \cs_generate_variant:Nn \__kernel_ior_open:Nn { No }
-\cs_new_protected:Npx \__ior_open_stream:Nn #1#2
+\cs_new_protected:Npe \__ior_open_stream:Nn #1#2
   {
     \tex_global:D \tex_chardef:D #1 = \exp_not:N \l__ior_stream_tl \scan_stop:
     \prop_gput:NVn \exp_not:N \g__ior_streams_prop #1 {#2}
@@ -10625,18 +10717,19 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \ior_shell_open:Nn #1#2
   {
     \sys_if_shell:TF
-      { \exp_args:No \__ior_shell_open:nN { \tl_to_str:n {#2} } #1 }
+      { \__ior_shell_open:oN { \tl_to_str:n {#2} } #1 }
       { \msg_error:nn { kernel } { pipe-failed } }
   }
 \cs_new_protected:Npn \__ior_shell_open:nN #1#2
   {
     \tl_if_in:nnTF {#1} { " }
       {
-        \msg_error:nnx
+        \msg_error:nne
           { kernel } { quote-in-shell } {#1}
       }
       { \__kernel_ior_open:Nn #2 { |#1 } }
   }
+\cs_generate_variant:Nn \__ior_shell_open:nN { o }
 \msg_new:nnnn { kernel } { pipe-failed }
   { Cannot~run~piped~system~commands. }
   {
@@ -10665,14 +10758,14 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       {
         \prop_get:NVNTF \g__ior_streams_prop #2 \l__ior_internal_tl
           {
-            \exp_args:Nx #1
+            \exp_args:Ne #1
               { \token_to_str:N #2 ~ open: ~ \l__ior_internal_tl }
           }
-          { \exp_args:Nx #1 { \token_to_str:N #2 ~ closed } }
+          { \exp_args:Ne #1 { \token_to_str:N #2 ~ closed } }
       }
   }
-\cs_new_protected:Npn \ior_show_list: { \__ior_list:N \msg_show:nnxxxx }
-\cs_new_protected:Npn \ior_log_list: { \__ior_list:N \msg_log:nnxxxx }
+\cs_new_protected:Npn \ior_show_list: { \__ior_list:N \msg_show:nneeee }
+\cs_new_protected:Npn \ior_log_list: { \__ior_list:N \msg_log:nneeee }
 \cs_new_protected:Npn \__ior_list:N #1
   {
     #1 { kernel } { show-streams }
@@ -10845,14 +10938,14 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \tl_new:N \l__iow_file_name_tl
 \cs_new_protected:Npn \iow_open:Nn #1#2
   {
-    \__kernel_tl_set:Nx \l__iow_file_name_tl
+    \__kernel_tl_set:Ne \l__iow_file_name_tl
       { \__kernel_file_name_sanitize:n {#2} }
     \iow_close:N #1
     \seq_gpop:NNTF \g__iow_streams_seq \l__iow_stream_tl
       { \__iow_open_stream:NV #1 \l__iow_file_name_tl }
       {
         \__iow_new:N #1
-        \__kernel_tl_set:Nx \l__iow_stream_tl { \int_eval:n {#1} }
+        \__kernel_tl_set:Ne \l__iow_stream_tl { \int_eval:n {#1} }
         \__iow_open_stream:NV #1 \l__iow_file_name_tl
       }
   }
@@ -10868,18 +10961,19 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \iow_shell_open:Nn #1#2
   {
     \sys_if_shell:TF
-      { \exp_args:No \__iow_shell_open:nN { \tl_to_str:n {#2} } #1 }
+      { \__iow_shell_open:oN { \tl_to_str:n {#2} } #1 }
       { \msg_error:nn { kernel } { pipe-failed } }
   }
 \cs_new_protected:Npn \__iow_shell_open:nN #1#2
   {
     \tl_if_in:nnTF {#1} { " }
       {
-        \msg_error:nnx
+        \msg_error:nne
           { kernel } { quote-in-shell } {#1}
       }
       { \__kernel_iow_open:Nn #2 { |#1 } }
   }
+\cs_generate_variant:Nn \__iow_shell_open:nN { o }
 \cs_new_protected:Npn \iow_close:N #1
   {
     \int_compare:nT { \c_log_iow < #1 < \c_term_iow }
@@ -10902,14 +10996,14 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       {
         \prop_get:NVNTF \g__iow_streams_prop #2 \l__iow_internal_tl
           {
-            \exp_args:Nx #1
+            \exp_args:Ne #1
               { \token_to_str:N #2 ~ open: ~ \l__iow_internal_tl }
           }
-          { \exp_args:Nx #1 { \token_to_str:N #2 ~ closed } }
+          { \exp_args:Ne #1 { \token_to_str:N #2 ~ closed } }
       }
   }
-\cs_new_protected:Npn \iow_show_list: { \__iow_list:N \msg_show:nnxxxx }
-\cs_new_protected:Npn \iow_log_list: { \__iow_list:N \msg_log:nnxxxx }
+\cs_new_protected:Npn \iow_show_list: { \__iow_list:N \msg_show:nneeee }
+\cs_new_protected:Npn \iow_log_list: { \__iow_list:N \msg_log:nneeee }
 \cs_new_protected:Npn \__iow_list:N #1
   {
     #1 { kernel } { show-streams }
@@ -10920,17 +11014,18 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
       { } { }
   }
-\cs_new_protected:Npn \iow_shipout_x:Nn #1#2
+\cs_new_protected:Npn \iow_shipout_e:Nn #1#2
   { \tex_write:D #1 {#2} }
-\cs_generate_variant:Nn \iow_shipout_x:Nn { c, Nx, cx }
+\cs_generate_variant:Nn \iow_shipout_e:Nn { Ne , c, ce }
 \cs_new_protected:Npn \iow_shipout:Nn #1#2
   { \tex_write:D #1 { \exp_not:n {#2} } }
-\cs_generate_variant:Nn \iow_shipout:Nn { c, Nx, cx }
+\cs_generate_variant:Nn \iow_shipout:Nn { Ne , c, ce }
+\cs_generate_variant:Nn \iow_shipout:Nn { Nx , cx }
 \cs_new_protected:Npn \__kernel_iow_with:Nnn #1#2
   {
     \int_compare:nNnTF {#1} = {#2}
       { \use:n }
-      { \exp_args:No \__iow_with:nNnn { \int_use:N #1 } #1 {#2} }
+      { \__iow_with:oNnn { \int_use:N #1 } #1 {#2} }
   }
 \cs_new_protected:Npn \__iow_with:nNnn #1#2#3#4
   {
@@ -10938,16 +11033,20 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     #4
     \int_set:Nn #2 {#1}
   }
+\cs_generate_variant:Nn \__iow_with:nNnn { o }
 \cs_new_protected:Npn \iow_now:Nn #1#2
   {
     \__kernel_iow_with:Nnn \tex_newlinechar:D { `\^^J }
       { \tex_immediate:D \tex_write:D #1 { \exp_not:n {#2} } }
   }
-\cs_generate_variant:Nn \iow_now:Nn { NV , Nx , c , cV , cx }
-\cs_set_protected:Npn \iow_log:x  { \iow_now:Nx \c_log_iow  }
+\cs_generate_variant:Nn \iow_now:Nn { NV , Ne , c , cV , ce }
+\cs_generate_variant:Nn \iow_now:Nn { Nx , cx }
 \cs_new_protected:Npn \iow_log:n  { \iow_now:Nn \c_log_iow  }
-\cs_set_protected:Npn \iow_term:x { \iow_now:Nx \c_term_iow }
+\cs_set_protected:Npn \iow_log:e  { \iow_now:Ne \c_log_iow  }
+\cs_generate_variant:Nn \iow_log:n { x }
 \cs_new_protected:Npn \iow_term:n { \iow_now:Nn \c_term_iow }
+\cs_set_protected:Npn \iow_term:e { \iow_now:Ne \c_term_iow }
+\cs_generate_variant:Nn \iow_term:n { x }
 \cs_new:Npn \iow_newline: { ^^J }
 \cs_new_eq:NN \iow_char:N \cs_to_str:N
 \int_new:N  \l_iow_line_count_int
@@ -10959,14 +11058,14 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new:Npn \__iow_unindent:w { }
 \cs_new_protected:Npn \__iow_set_indent:n #1
   {
-    \__kernel_tl_set:Nx \l__iow_one_indent_tl
+    \__kernel_tl_set:Ne \l__iow_one_indent_tl
       { \exp_args:No \__kernel_str_to_other_fast:n { \tl_to_str:n {#1} } }
     \int_set:Nn \l__iow_one_indent_int
       { \str_count:N \l__iow_one_indent_tl }
     \exp_last_unbraced:NNo
       \cs_set:Npn \__iow_unindent:w \l__iow_one_indent_tl { }
   }
-\exp_args:Nx \__iow_set_indent:n { \prg_replicate:nn { 4 } { ~ } }
+\exp_args:Ne \__iow_set_indent:n { \prg_replicate:nn { 4 } { ~ } }
 \tl_new:N \l__iow_indent_tl
 \int_new:N \l__iow_indent_int
 \tl_new:N \l__iow_line_tl
@@ -10975,13 +11074,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \tl_new:N \l__iow_wrap_tl
 \group_begin:
   \int_set:Nn \tex_escapechar:D { -1 }
-  \tl_const:Nx \c__iow_wrap_marker_tl
+  \tl_const:Ne \c__iow_wrap_marker_tl
     { \tl_to_str:n { \^^I \^^O \^^W \^^_ \^^W \^^R \^^A \^^P } }
 \group_end:
 \tl_map_inline:nn
   { { end } { newline } { allow_break } { indent } { unindent } }
   {
-    \tl_const:cx { c__iow_wrap_ #1 _marker_tl }
+    \tl_const:ce { c__iow_wrap_ #1 _marker_tl }
       {
         \c__iow_wrap_marker_tl
         #1
@@ -10993,7 +11092,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \msg_error:nnnn { kernel } { iow-indent }
       { \iow_wrap:nnnN } { \iow_wrap_allow_break: }
   }
-\cs_new:Npx \__iow_wrap_allow_break: { \c__iow_wrap_allow_break_marker_tl }
+\cs_new:Npe \__iow_wrap_allow_break: { \c__iow_wrap_allow_break_marker_tl }
 \cs_new:Npn \__iow_wrap_allow_break_error:
   {
     \msg_expandable_error:nnnn { kernel } { iow-indent }
@@ -11005,7 +11104,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { \iow_wrap:nnnN } { \iow_indent:n } {#1}
     #1
   }
-\cs_new:Npx \__iow_indent:n #1
+\cs_new:Npe \__iow_indent:n #1
   {
     \c__iow_wrap_indent_marker_tl
     #1
@@ -11022,11 +11121,11 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \group_begin:
       \cs_if_exist_use:N \conditionally@traceoff
       \int_set:Nn \tex_escapechar:D { -1 }
-      \cs_set:Npx \{ { \token_to_str:N \{ }
-      \cs_set:Npx \# { \token_to_str:N \# }
-      \cs_set:Npx \} { \token_to_str:N \} }
-      \cs_set:Npx \% { \token_to_str:N \% }
-      \cs_set:Npx \~ { \token_to_str:N \~ }
+      \cs_set:Npe \{ { \token_to_str:N \{ }
+      \cs_set:Npe \# { \token_to_str:N \# }
+      \cs_set:Npe \} { \token_to_str:N \} }
+      \cs_set:Npe \% { \token_to_str:N \% }
+      \cs_set:Npe \~ { \token_to_str:N \~ }
       \int_set:Nn \tex_escapechar:D { 92 }
       \cs_set_eq:NN \\ \iow_newline:
       \cs_set_eq:NN \  \c_catcode_other_space_tl
@@ -11034,11 +11133,11 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \cs_set_eq:NN \iow_indent:n \__iow_indent:n
       #3
       \cs_set_eq:NN \protect \token_to_str:N
-      \__kernel_tl_set:Nx \l__iow_wrap_tl {#1}
+      \__kernel_tl_set:Ne \l__iow_wrap_tl {#1}
       \cs_set_eq:NN \iow_wrap_allow_break: \__iow_wrap_allow_break_error:
       \cs_set_eq:NN \iow_indent:n \__iow_indent_error:n
-      \__kernel_tl_set:Nx \l__iow_newline_tl { \iow_newline: #2 }
-      \__kernel_tl_set:Nx \l__iow_newline_tl { \tl_to_str:N \l__iow_newline_tl }
+      \__kernel_tl_set:Ne \l__iow_newline_tl { \iow_newline: #2 }
+      \__kernel_tl_set:Ne \l__iow_newline_tl { \tl_to_str:N \l__iow_newline_tl }
       \int_set:Nn \l__iow_line_target_int
         { \l_iow_line_count_int - \str_count:N \l__iow_newline_tl + 1 }
        \int_compare:nNnT { \l__iow_line_target_int } < 0
@@ -11051,15 +11150,15 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \exp_args:NNf \group_end:
     #4 { \tl_to_str:N \l__iow_wrap_tl }
   }
-\cs_generate_variant:Nn \iow_wrap:nnnN { nx }
+\cs_generate_variant:Nn \iow_wrap:nnnN { ne }
 \cs_new_protected:Npn \__iow_wrap_do:
   {
-    \__kernel_tl_set:Nx \l__iow_wrap_tl
+    \__kernel_tl_set:Ne \l__iow_wrap_tl
       {
         \exp_args:No \__kernel_str_to_other_fast:n \l__iow_wrap_tl
         \c__iow_wrap_end_marker_tl
       }
-    \__kernel_tl_set:Nx \l__iow_wrap_tl
+    \__kernel_tl_set:Ne \l__iow_wrap_tl
       {
         \exp_after:wN \__iow_wrap_fix_newline:w \l__iow_wrap_tl
           ^^J \q__iow_nil ^^J \s__iow_stop
@@ -11217,7 +11316,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__iow_wrap_allow_break:n #1
   {
-    \__kernel_tl_set:Nx \l__iow_line_tl
+    \__kernel_tl_set:Ne \l__iow_line_tl
       { \l__iow_line_tl \__iow_wrap_trim:N \l__iow_line_part_tl }
     \bool_set_false:N \l__iow_line_break_bool
     \tl_if_empty:NTF \l__iow_line_part_tl
@@ -11226,7 +11325,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__iow_wrap_indent:n #1
   {
-    \tl_put_right:Nx \l__iow_line_tl { \l__iow_line_part_tl }
+    \tl_put_right:Ne \l__iow_line_tl { \l__iow_line_part_tl }
     \bool_set_false:N \l__iow_line_break_bool
     \int_add:Nn \l__iow_indent_int { \l__iow_one_indent_int }
     \tl_put_right:No \l__iow_indent_tl { \l__iow_one_indent_tl }
@@ -11234,10 +11333,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__iow_wrap_unindent:n #1
   {
-    \tl_put_right:Nx \l__iow_line_tl { \l__iow_line_part_tl }
+    \tl_put_right:Ne \l__iow_line_tl { \l__iow_line_part_tl }
     \bool_set_false:N \l__iow_line_break_bool
     \int_sub:Nn \l__iow_indent_int { \l__iow_one_indent_int }
-    \__kernel_tl_set:Nx \l__iow_indent_tl
+    \__kernel_tl_set:Ne \l__iow_indent_tl
       { \exp_after:wN \__iow_unindent:w \l__iow_indent_tl }
     \__iow_wrap_chunk:nw {#1}
   }
@@ -11256,9 +11355,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__iow_wrap_store_do:n #1
   {
-    \__kernel_tl_set:Nx \l__iow_line_tl
+    \__kernel_tl_set:Ne \l__iow_line_tl
       { \l__iow_line_tl \l__iow_line_part_tl }
-    \__kernel_tl_set:Nx \l__iow_wrap_tl
+    \__kernel_tl_set:Ne \l__iow_wrap_tl
       {
         \l__iow_wrap_tl
         \l__iow_newline_tl
@@ -11275,6 +11374,8 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \cs_new:Npn \__iow_wrap_trim_aux:w ##1 \s__iow_mark ##2 \s__iow_stop {##1}
   }
 \exp_args:NV \__iow_tmp:w \c_catcode_other_space_tl
+\cs_new_eq:NN \iow_shipout_x:Nn \iow_shipout_e:Nn
+\cs_generate_variant:Nn \iow_shipout_x:Nn { Nx , c, cx }
 \tl_new:N \l__file_internal_tl
 \str_new:N \g_file_curr_dir_str
 \str_new:N \g_file_curr_ext_str
@@ -11287,7 +11388,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         {
           \cs_set:Npn \__file_tmp:w ##1 " ##2 " ##3 \s__file_stop
             { { } {##2} {  } }
-          \seq_gput_right:Nx \g__file_stack_seq
+          \seq_gput_right:Ne \g__file_stack_seq
             {
               \exp_after:wN \__file_tmp:w \tex_jobname:D
                 " \tex_jobname:D " \s__file_stop
@@ -11401,12 +11502,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { #1 }
       { "#1" }
   }
-\tl_const:Nx \c__file_marker_tl { : \token_to_str:N : }
+\tl_const:Ne \c__file_marker_tl { : \token_to_str:N : }
 \cs_new_protected:Npn \file_get:nnN #1#2#3
   {
     \file_get:nnNF {#1} {#2} #3
       { \tl_set:Nn #3 { \q_no_value } }
   }
+\cs_generate_variant:Nn \file_get:nnN { V }
 \prg_new_protected_conditional:Npnn \file_get:nnN #1#2#3 { T , F , TF }
   {
     \file_get_full_name:nNTF {#1} \l__file_full_name_tl
@@ -11418,7 +11520,8 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
       { \prg_return_false: }
   }
-\cs_new_protected:Npx \__file_get_aux:nnN #1#2#3
+\prg_generate_conditional_variant:Nnn \file_get:nnN { V } { T , F , TF }
+\cs_new_protected:Npe \__file_get_aux:nnN #1#2#3
   {
     \exp_not:N \if_false: { \exp_not:N \fi:
     \group_begin:
@@ -11448,6 +11551,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \exp_args:Ne \__file_full_name:n
       { \__kernel_file_name_sanitize:n {#1} }
   }
+\cs_generate_variant:Nn \file_full_name:n { V }
 \cs_new:Npn \__file_full_name:n #1
   {
     \tl_if_blank:nF {#1}
@@ -11527,7 +11631,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
       { \__file_ext_check:nnw {#1} { #2 #3 / } #4 / #5 \s__file_stop }
   }
-\cs_new:Npx \__file_ext_check:nnnw #1#2#3#4 . #5 . #6 \s__file_stop
+\cs_new:Npe \__file_ext_check:nnnw #1#2#3#4 . #5 . #6 \s__file_stop
   {
     \exp_not:N \__file_quark_if_nil:nTF {#5}
       {
@@ -11558,20 +11662,21 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_generate_variant:Nn \file_get_full_name:nN { V }
 \prg_new_protected_conditional:Npnn \file_get_full_name:nN #1#2 { T , F , TF }
   {
-    \__kernel_tl_set:Nx #2
+    \__kernel_tl_set:Ne #2
       { \file_full_name:n {#1} }
     \tl_if_empty:NTF #2
       { \prg_return_false: }
       { \prg_return_true: }
   }
-\cs_generate_variant:Nn \file_get_full_name:nNT  { V }
-\cs_generate_variant:Nn \file_get_full_name:nNF  { V }
-\cs_generate_variant:Nn \file_get_full_name:nNTF { V }
+\prg_generate_conditional_variant:Nnn \file_get_full_name:nN
+  { V } { T , F ,  TF }
 \ior_new:N \g__file_internal_ior
 \cs_new:Npn \file_size:n #1
   { \__file_details:nn {#1} { size } }
+\cs_generate_variant:Nn \file_size:n { V }
 \cs_new:Npn \file_timestamp:n #1
   { \__file_details:nn {#1} { moddate } }
+\cs_generate_variant:Nn \file_timestamp:n { V }
 \cs_new:Npn \__file_details:nn #1#2
   {
     \exp_args:Ne \__file_details_aux:nn
@@ -11584,6 +11689,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new:Npn \file_mdfive_hash:n #1
   { \exp_args:Ne \__file_mdfive_hash:n { \file_full_name:n {#1} } }
+\cs_generate_variant:Nn \file_mdfive_hash:n { V }
 \cs_new:Npn \__file_mdfive_hash:n #1
   { \tex_mdfivesum:D file {#1} }
 \cs_new:Npn \file_hex_dump:nnn #1#2#3
@@ -11593,6 +11699,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { \int_eval:n {#2} }
       { \int_eval:n {#3} }
   }
+\cs_generate_variant:Nn \file_hex_dump:nnn { V }
 \cs_new:Npn \__file_hex_dump_auxi:nnn #1#2#3
   {
     \bool_lazy_any:nF
@@ -11636,6 +11743,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new:Npn \file_hex_dump:n #1
   { \exp_args:Ne \__file_hex_dump:n { \file_full_name:n {#1} } }
+\cs_generate_variant:Nn \file_hex_dump:n { V }
 \sys_if_engine_luatex:TF
   {
     \cs_new:Npn \__file_hex_dump:n #1
@@ -11653,23 +11761,35 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \file_get_hex_dump:nN #1#2
   { \file_get_hex_dump:nNF {#1} #2 { \tl_set:Nn #2 { \q_no_value } } }
+\cs_generate_variant:Nn \file_get_hex_dump:nN { V }
 \cs_new_protected:Npn \file_get_mdfive_hash:nN #1#2
   { \file_get_mdfive_hash:nNF {#1} #2 { \tl_set:Nn #2 { \q_no_value } } }
+\cs_generate_variant:Nn \file_get_mdfive_hash:nN { V }
 \cs_new_protected:Npn \file_get_size:nN #1#2
   { \file_get_size:nNF {#1} #2 { \tl_set:Nn #2 { \q_no_value } } }
+\cs_generate_variant:Nn \file_get_size:nN { V }
 \cs_new_protected:Npn \file_get_timestamp:nN #1#2
   { \file_get_timestamp:nNF {#1} #2 { \tl_set:Nn #2 { \q_no_value } } }
+\cs_generate_variant:Nn \file_get_timestamp:nN { V }
 \prg_new_protected_conditional:Npnn \file_get_hex_dump:nN #1#2 { T , F , TF }
   { \__file_get_details:nnN {#1} { hex_dump } #2 }
+\prg_generate_conditional_variant:Nnn \file_get_hex_dump:nN
+  { V } { T , F , TF }
 \prg_new_protected_conditional:Npnn \file_get_mdfive_hash:nN #1#2 { T , F , TF }
   { \__file_get_details:nnN {#1} { mdfive_hash } #2 }
+\prg_generate_conditional_variant:Nnn \file_get_mdfive_hash:nN
+  { V } { T , F , TF }
 \prg_new_protected_conditional:Npnn \file_get_size:nN #1#2 { T , F , TF }
   { \__file_get_details:nnN {#1} { size } #2 }
+\prg_generate_conditional_variant:Nnn \file_get_size:nN
+  { V } { T , F , TF }
 \prg_new_protected_conditional:Npnn \file_get_timestamp:nN #1#2 { T , F , TF }
   { \__file_get_details:nnN {#1} { timestamp } #2 }
+\prg_generate_conditional_variant:Nnn \file_get_timestamp:nN
+  { V } { T , F , TF }
 \cs_new_protected:Npn \__file_get_details:nnN #1#2#3
   {
-    \__kernel_tl_set:Nx #3
+    \__kernel_tl_set:Ne #3
       { \use:c { file_ #2 :n } {#1} }
     \tl_if_empty:NTF #3
       { \prg_return_false: }
@@ -11680,15 +11800,18 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \file_get_hex_dump:nnnNF {#1} {#2} {#3} #4
       { \tl_set:Nn #4 { \q_no_value } }
   }
+\cs_generate_variant:Nn \file_get_hex_dump:nnnN { V }
 \prg_new_protected_conditional:Npnn \file_get_hex_dump:nnnN #1#2#3#4
   { T , F , TF }
   {
-    \__kernel_tl_set:Nx #4
+    \__kernel_tl_set:Ne #4
       { \file_hex_dump:nnn {#1} {#2} {#3} }
     \tl_if_empty:NTF #4
       { \prg_return_false: }
       { \prg_return_true: }
   }
+\prg_generate_conditional_variant:Nnn \file_get_hex_dump:nnnN
+  { V } { T , F , TF }
 \cs_new_eq:NN \__file_str_cmp:nn \tex_strcmp:D
 \prg_new_conditional:Npnn \file_compare_timestamp:nNn #1#2#3
   { p , T , F , TF }
@@ -11698,6 +11821,8 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { \file_full_name:n {#3} }
       #2
    }
+\prg_generate_conditional_variant:Nnn \file_compare_timestamp:nNn
+  { nNV , V , VNV } { p , T , F , TF }
 \cs_new:Npn \__file_compare_timestamp:nnN #1#2#3
   {
     \tl_if_blank:nTF {#1}
@@ -11731,28 +11856,30 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
   }
 \cs_new_eq:NN \__file_timestamp:n \tex_filemoddate:D
-\prg_new_protected_conditional:Npnn \file_if_exist:n #1 { T , F , TF }
+\prg_new_conditional:Npnn \file_if_exist:n #1 { p , T , F , TF }
   {
-    \file_get_full_name:nNTF {#1} \l__file_full_name_tl
-      { \prg_return_true: }
+    \tl_if_blank:eTF { \file_full_name:n {#1} }
       { \prg_return_false: }
+      { \prg_return_true: }
   }
-\prg_generate_conditional_variant:Nnn \file_if_exist:n { V } { T , F , TF }
+\prg_generate_conditional_variant:Nnn \file_if_exist:n { V } { p , T , F , TF }
 \cs_new_protected:Npn \file_if_exist_input:n #1
   {
     \file_get_full_name:nNT {#1} \l__file_full_name_tl
       { \__file_input:V \l__file_full_name_tl }
   }
+\cs_generate_variant:Nn \file_if_exist_input:n { V }
 \cs_new_protected:Npn \file_if_exist_input:nF #1#2
   {
     \file_get_full_name:nNTF {#1} \l__file_full_name_tl
       { \__file_input:V \l__file_full_name_tl }
       {#2}
   }
+\cs_generate_variant:Nn \file_if_exist_input:nF { V }
 \cs_new_protected:Npn \file_input_stop: { \tex_endinput:D }
 \cs_new_protected:Npn \__kernel_file_missing:n #1
   {
-    \msg_error:nnx { kernel } { file-not-found }
+    \msg_error:nne { kernel } { file-not-found }
       { \__kernel_file_name_sanitize:n {#1} }
   }
 \cs_new_protected:Npn \file_input:n #1
@@ -11762,7 +11889,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { \__kernel_file_missing:n {#1} }
   }
 \cs_generate_variant:Nn \file_input:n { V }
-\cs_new_protected:Npx \__file_input:n #1
+\cs_new_protected:Npe \__file_input:n #1
   {
     \exp_not:N \clist_if_exist:NTF \exp_not:N \@filelist
       { \exp_not:N \@addtofilelist {#1} }
@@ -11777,7 +11904,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_generate_variant:Nn \__file_input:n { V }
 \cs_new_protected:Npn \__file_input_push:n #1
   {
-    \seq_gpush:Nx \g__file_stack_seq
+    \seq_gpush:Ne \g__file_stack_seq
       {
         { \g_file_curr_dir_str }
         { \g_file_curr_name_str }
@@ -11804,7 +11931,8 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new:Npn \file_input_raw:n #1
   { \exp_args:Ne \__file_input_raw:nn { \file_full_name:n {#1} } {#1} }
-\cs_new:Npx \__file_input_raw:nn #1#2
+\cs_generate_variant:Nn \file_input_raw:n { V }
+\cs_new:Npe \__file_input_raw:nn #1#2
   {
     \exp_not:N \tl_if_blank:nTF {#1}
       {
@@ -11825,11 +11953,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \file_parse_full_name_apply:nN {#1}
       \prg_do_nothing:
   }
+\cs_generate_variant:Nn \file_parse_full_name:n { V }
 \cs_new:Npn \file_parse_full_name_apply:nN #1
   {
     \exp_args:Ne \__file_parse_full_name_auxi:nN
       { \__kernel_file_name_sanitize:n {#1} }
   }
+\cs_generate_variant:Nn \file_parse_full_name_apply:nN { V }
 \cs_new:Npn \__file_parse_full_name_auxi:nN #1
   {
     \__file_parse_full_name_area:nw { } #1
@@ -11877,14 +12007,14 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \str_set:Nn #6 {#3}
   }
 \cs_generate_variant:Nn \file_parse_full_name:nNNN { V }
-\cs_new_protected:Npn \file_show_list: { \__file_list:N \msg_show:nnxxxx }
-\cs_new_protected:Npn \file_log_list: { \__file_list:N \msg_log:nnxxxx }
+\cs_new_protected:Npn \file_show_list: { \__file_list:N \msg_show:nneeee }
+\cs_new_protected:Npn \file_log_list: { \__file_list:N \msg_log:nneeee }
 \cs_new_protected:Npn \__file_list:N #1
   {
     \seq_clear:N \l__file_tmp_seq
     \clist_if_exist:NT \@filelist
       {
-        \exp_args:NNx \seq_set_from_clist:Nn \l__file_tmp_seq
+        \exp_args:NNe \seq_set_from_clist:Nn \l__file_tmp_seq
           { \tl_to_str:N \@filelist }
       }
     \seq_concat:NNN \l__file_tmp_seq \l__file_tmp_seq \g__file_record_seq
@@ -11898,7 +12028,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \AtBeginDocument
       {
-        \exp_args:NNx \seq_set_from_clist:Nn \l__file_tmp_seq
+        \exp_args:NNe \seq_set_from_clist:Nn \l__file_tmp_seq
           { \tl_to_str:N \@filelist }
         \seq_gconcat:NNN
           \g__file_record_seq
@@ -11964,7 +12094,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new:Npn \__file_parse_version:w #1 - #2 - #3 \s__file_stop {#1#2#3}
 \cs_new_protected:Npn \__file_mismatched_dependency_error:nn #1 #2
   {
-    \exp_args:NNx \ior_shell_open:Nn \g__file_internal_ior
+    \exp_args:NNe \ior_shell_open:Nn \g__file_internal_ior
       {
         kpsewhich ~ --all ~
           --engine = \c_sys_engine_exec_str
@@ -12054,7 +12184,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \sys_if_engine_luatex:TF
   {
-    \str_const:Nx \c_sys_platform_str
+    \str_const:Ne \c_sys_platform_str
       { \tex_directlua:D { tex.print(os.type) } }
   }
   {
@@ -12346,7 +12476,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \int_gincr:N \g__kernel_prg_map_int
     \exp_args:NNc \__dim_step:NNnnnn
-      \cs_gset_protected:Npx
+      \cs_gset_protected:Npe
       { __dim_map_ \int_use:N \g__kernel_prg_map_int :w }
       {#1}{#2}{#3}
       {
@@ -12387,10 +12517,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \exp_after:wN
       \__dim_to_decimal:w \dim_use:N \__dim_eval:w #1 \__dim_eval_end:
   }
-\use:x
+\use:e
   {
     \cs_new:Npn \exp_not:N \__dim_to_decimal:w
-      ##1 . ##2 \tl_to_str:n { pt }
+      #1 . #2 \tl_to_str:n { pt }
   }
       {
         \int_compare:nNnTF {#2} > \c_zero_int
@@ -12934,9 +13064,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \keys_define:nn
   { \__keys_define:onn \l__keys_module_str }
+\cs_generate_variant:Nn \keys_define:nn { ne , nx }
 \cs_new_protected:Npn \__keys_define:nnn #1#2#3
   {
-    \str_set:Nx \l__keys_module_str { \__keys_trim_spaces:n {#2} }
+    \str_set:Ne \l__keys_module_str { \__keys_trim_spaces:n {#2} }
     \keyval_parse:NNn \__keys_define:n \__keys_define:nn {#3}
     \str_set:Nn \l__keys_module_str {#1}
   }
@@ -12959,14 +13090,14 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       {
         \str_if_empty:NF \l__keys_property_str
           {
-            \msg_error:nnxx { keys } { property-unknown }
+            \msg_error:nnee { keys } { property-unknown }
               \l__keys_property_str \l_keys_path_str
           }
       }
   }
 \cs_new_protected:Npn \__keys_property_find:n #1
   {
-    \cs_set_nopar:Npx \l__keys_property_str { \__keys_trim_spaces:n { #1 } }
+    \cs_set_nopar:Npe \l__keys_property_str { \__keys_trim_spaces:n { #1 } }
     \exp_after:wN \__keys_property_find_auxi:w \l__keys_property_str
       \s__keys_nil \__keys_property_find_auxii:w
       . \s__keys_nil \__keys_property_find_err:w
@@ -12979,22 +13110,22 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     #1 \s__keys_mark #2 \s__keys_nil \__keys_property_find_auxii:w . \s__keys_nil
     \__keys_property_find_err:w
   {
-    \cs_set_nopar:Npx \l_keys_path_str
+    \cs_set_nopar:Npe \l_keys_path_str
       { \str_if_empty:NF \l__keys_module_str { \l__keys_module_str / } #1 }
     \__keys_property_find_auxi:w #2 \s__keys_nil \__keys_property_find_auxiii:w . \s__keys_nil
       \__keys_property_find_auxiv:w
   }
 \cs_new_protected:Npn \__keys_property_find_auxiii:w #1 \s__keys_mark
   {
-    \cs_set_nopar:Npx \l_keys_path_str { \l_keys_path_str . #1 }
+    \cs_set_nopar:Npe \l_keys_path_str { \l_keys_path_str . #1 }
     \__keys_property_find_auxi:w
   }
 \cs_new_protected:Npn \__keys_property_find_auxiv:w
     #1 \s__keys_nil \__keys_property_find_auxiii:w
     \s__keys_mark \s__keys_nil \__keys_property_find_auxiv:w
   {
-    \cs_set_nopar:Npx \l__keys_property_str { . #1 }
-    \cs_set_nopar:Npx \l_keys_path_str
+    \cs_set_nopar:Npe \l__keys_property_str { . #1 }
+    \cs_set_nopar:Npe \l_keys_path_str
       { \exp_after:wN \__keys_trim_spaces:n \exp_after:wN { \l_keys_path_str } }
     \tl_set_eq:NN \l_keys_path_tl \l_keys_path_str
   }
@@ -13012,7 +13143,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           \l__keys_property_str \s__keys_stop
           { \use:c { \c__keys_props_root_str \l__keys_property_str } }
           {
-            \msg_error:nnxx { keys } { property-requires-value }
+            \msg_error:nnee { keys } { property-requires-value }
               \l__keys_property_str \l_keys_path_str
           }
       }
@@ -13031,13 +13162,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \bool_if_exist:NF #1 { \bool_new:N #1 }
     \__keys_choice_make:
-    \__keys_cmd_set:nx { \l_keys_path_str / true }
+    \__keys_cmd_set:ne { \l_keys_path_str / true }
       { \exp_not:c { bool_ #2 set_ #3 :N } \exp_not:N #1 }
-    \__keys_cmd_set:nx { \l_keys_path_str / false }
+    \__keys_cmd_set:ne { \l_keys_path_str / false }
       { \exp_not:c { bool_ #2 set_ #4 :N } \exp_not:N #1 }
     \__keys_cmd_set_direct:nn { \l_keys_path_str / unknown }
       {
-        \msg_error:nnx { keys } { boolean-values-only }
+        \msg_error:nne { keys } { boolean-values-only }
           \l_keys_path_str
       }
     \__keys_default_set:n { true }
@@ -13056,7 +13187,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           { \c__keys_type_root_str \__keys_parent:o \l_keys_path_str }
           { choice }
           {
-            \msg_error:nnxx { keys } { nested-choice-key }
+            \msg_error:nnee { keys } { nested-choice-key }
               \l_keys_path_tl { \__keys_parent:o \l_keys_path_str }
           }
           { \__keys_choice_make_aux:N #1 }
@@ -13070,7 +13201,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \__keys_cmd_set_direct:nn \l_keys_path_str { #1 {##1} }
     \__keys_cmd_set_direct:nn { \l_keys_path_str / unknown }
       {
-        \msg_error:nnxx { keys } { choice-unknown }
+        \msg_error:nnee { keys } { choice-unknown }
           \l_keys_path_str {##1}
       }
   }
@@ -13085,7 +13216,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \clist_map_inline:nn {#2}
       {
         \int_incr:N \l_keys_choice_int
-        \__keys_cmd_set:nx
+        \__keys_cmd_set:ne
           { \l_keys_path_str / \__keys_trim_spaces:n {##1} }
           {
             \tl_set:Nn \exp_not:N \l_keys_choice_tl {##1}
@@ -13097,12 +13228,12 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__keys_cmd_set:nn #1#2
   {  \__keys_cmd_set_direct:nn {#1} { \__keys_precompile:n {#2} } }
-\cs_generate_variant:Nn \__keys_cmd_set:nn { nx , Vn , Vo }
+\cs_generate_variant:Nn \__keys_cmd_set:nn { ne , Vn , Vo }
 \cs_new_protected:Npn \__keys_cmd_set_direct:nn #1#2
   { \cs_set_protected:cpn { \c__keys_code_root_str #1 } ##1 {#2} }
 \cs_new_protected:Npn \__keys_cs_set:NNpn #1#2#3#
   {
-    \cs_set_protected:cpx { \c__keys_code_root_str \l_keys_path_str } ##1
+    \cs_set_protected:cpe { \c__keys_code_root_str \l_keys_path_str } ##1
       {
         \__keys_precompile:n
           { #1 \exp_not:N #2 \exp_not:n {#3} {##1} }
@@ -13119,7 +13250,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           \tex_undefined:D
       }
       {
-        \cs_set_nopar:cpx
+        \cs_set_nopar:cpe
           { \c__keys_default_root_str \l_keys_path_str }
           { \exp_not:n {#1} }
         \__keys_value_requirement:nn { required } { false }
@@ -13168,13 +13299,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__keys_legacy_if_set:nnnn #1#2#3#4
   {
     \__keys_choice_make:
-    \__keys_cmd_set:nx { \l_keys_path_str / true }
+    \__keys_cmd_set:ne { \l_keys_path_str / true }
       { \exp_not:c { legacy_if_#2  set_ #3 :n } { \exp_not:n {#1} } }
-    \__keys_cmd_set:nx { \l_keys_path_str / false }
+    \__keys_cmd_set:ne { \l_keys_path_str / false }
       { \exp_not:c { legacy_if_#2  set_ #4 :n } { \exp_not:n {#1} } }
     \__keys_cmd_set:nn { \l_keys_path_str / unknown }
       {
-        \msg_error:nnx { keys } { boolean-values-only }
+        \msg_error:nne { keys } { boolean-values-only }
           \l_keys_path_str
       }
     \__keys_default_set:n { true }
@@ -13202,7 +13333,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \prop_if_exist:NF #1 { \prop_new:N #1 }
     \exp_after:wN \__keys_find_key_module:wNN \l_keys_path_str \s__keys_stop
       \l__keys_tmpa_tl \l__keys_tmpb_tl
-    \__keys_cmd_set:nx \l_keys_path_str
+    \__keys_cmd_set:ne \l_keys_path_str
       {
         \exp_not:c { prop_ #2 put:Nnn }
         \exp_not:N #1
@@ -13244,7 +13375,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           }
       }
       {
-        \msg_error:nnx { keys }
+        \msg_error:nne { keys }
           { boolean-values-only }
           { .value_ #1 :n }
       }
@@ -13253,7 +13384,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \bool_if:NF \l__keys_no_value_bool
       {
-        \msg_error:nnxx { keys } { value-forbidden }
+        \msg_error:nnee { keys } { value-forbidden }
           \l_keys_path_str \l_keys_value_tl
         \use_none:nnn
       }
@@ -13262,7 +13393,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \bool_if:NT \l__keys_no_value_bool
       {
-        \msg_error:nnx { keys } { value-required }
+        \msg_error:nne { keys } { value-required }
           \l_keys_path_str
         \use_none:nnn
       }
@@ -13304,7 +13435,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \prop_get:NVNF #1 \l__keys_module_str \l__keys_tmpa_tl
       { \tl_clear:N \l__keys_tmpa_tl }
-    \tl_set:Nx \l__keys_tmpb_tl
+    \tl_set:Ne \l__keys_tmpb_tl
       { \exp_after:wN \__keys_usage:w \l_keys_path_str \s__keys_stop }
     \bool_if:NTF #2
       { \clist_put_right:NV \l__keys_tmpa_tl \l__keys_tmpb_tl }
@@ -13316,7 +13447,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__keys_variable_set:NnnN #1#2#3#4
   {
     \use:c { #2_if_exist:NF } #1 { \use:c { #2 _new:N } #1 }
-    \__keys_cmd_set:nx \l_keys_path_str
+    \__keys_cmd_set:ne \l_keys_path_str
       {
         \exp_not:c { #2 _ #3 set:N #4 }
         \exp_not:N #1
@@ -13352,6 +13483,8 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \__keys_choices_make:nn #1 }
 \cs_new_protected:cpn { \c__keys_props_root_str .choices:Vn } #1
   { \exp_args:NV \__keys_choices_make:nn #1 }
+\cs_new_protected:cpn { \c__keys_props_root_str .choices:en } #1
+  { \exp_args:Ne \__keys_choices_make:nn #1 }
 \cs_new_protected:cpn { \c__keys_props_root_str .choices:on } #1
   { \exp_args:No \__keys_choices_make:nn #1 }
 \cs_new_protected:cpn { \c__keys_props_root_str .choices:xn } #1
@@ -13386,6 +13519,8 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \__keys_default_set:n {#1} }
 \cs_new_protected:cpn { \c__keys_props_root_str .default:V } #1
   { \exp_args:NV \__keys_default_set:n #1 }
+\cs_new_protected:cpn { \c__keys_props_root_str .default:e } #1
+  { \exp_args:Ne \__keys_default_set:n {#1} }
 \cs_new_protected:cpn { \c__keys_props_root_str .default:o } #1
   { \exp_args:No \__keys_default_set:n {#1} }
 \cs_new_protected:cpn { \c__keys_props_root_str .default:x } #1
@@ -13414,6 +13549,8 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \__keys_initialise:n {#1} }
 \cs_new_protected:cpn { \c__keys_props_root_str .initial:V } #1
   { \exp_args:NV \__keys_initialise:n #1 }
+\cs_new_protected:cpn { \c__keys_props_root_str .initial:e } #1
+  { \exp_args:Ne \__keys_initialise:n {#1} }
 \cs_new_protected:cpn { \c__keys_props_root_str .initial:o } #1
   { \exp_args:No \__keys_initialise:n {#1} }
 \cs_new_protected:cpn { \c__keys_props_root_str .initial:x } #1
@@ -13444,6 +13581,8 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \__keys_multichoices_make:nn #1 }
 \cs_new_protected:cpn { \c__keys_props_root_str .multichoices:Vn } #1
   { \exp_args:NV \__keys_multichoices_make:nn #1 }
+\cs_new_protected:cpn { \c__keys_props_root_str .multichoices:en } #1
+  { \exp_args:Ne \__keys_multichoices_make:nn #1 }
 \cs_new_protected:cpn { \c__keys_props_root_str .multichoices:on } #1
   { \exp_args:No \__keys_multichoices_make:nn #1 }
 \cs_new_protected:cpn { \c__keys_props_root_str .multichoices:xn } #1
@@ -13476,34 +13615,34 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \__keys_variable_set:NnnN #1 { str } { } n }
 \cs_new_protected:cpn { \c__keys_props_root_str .str_set:c } #1
   { \__keys_variable_set:cnnN {#1} { str } { } n }
-\cs_new_protected:cpn { \c__keys_props_root_str .str_set_x:N } #1
-  { \__keys_variable_set:NnnN #1 { str } { } x }
-\cs_new_protected:cpn { \c__keys_props_root_str .str_set_x:c } #1
-  { \__keys_variable_set:cnnN {#1} { str } { } x }
+\cs_new_protected:cpn { \c__keys_props_root_str .str_set_e:N } #1
+  { \__keys_variable_set:NnnN #1 { str } { } e }
+\cs_new_protected:cpn { \c__keys_props_root_str .str_set_e:c } #1
+  { \__keys_variable_set:cnnN {#1} { str } { } e }
 \cs_new_protected:cpn { \c__keys_props_root_str .str_gset:N } #1
   { \__keys_variable_set:NnnN #1 { str } { g } n }
 \cs_new_protected:cpn { \c__keys_props_root_str .str_gset:c } #1
   { \__keys_variable_set:cnnN {#1} { str } { g } n }
-\cs_new_protected:cpn { \c__keys_props_root_str .str_gset_x:N } #1
-  { \__keys_variable_set:NnnN #1 { str } { g } x }
-\cs_new_protected:cpn { \c__keys_props_root_str .str_gset_x:c } #1
-  { \__keys_variable_set:cnnN {#1} { str } { g } x }
+\cs_new_protected:cpn { \c__keys_props_root_str .str_gset_e:N } #1
+  { \__keys_variable_set:NnnN #1 { str } { g } e }
+\cs_new_protected:cpn { \c__keys_props_root_str .str_gset_e:c } #1
+  { \__keys_variable_set:cnnN {#1} { str } { g } e }
 \cs_new_protected:cpn { \c__keys_props_root_str .tl_set:N } #1
   { \__keys_variable_set:NnnN #1 { tl } { } n }
 \cs_new_protected:cpn { \c__keys_props_root_str .tl_set:c } #1
   { \__keys_variable_set:cnnN {#1} { tl } { } n }
-\cs_new_protected:cpn { \c__keys_props_root_str .tl_set_x:N } #1
-  { \__keys_variable_set:NnnN #1 { tl } { } x }
-\cs_new_protected:cpn { \c__keys_props_root_str .tl_set_x:c } #1
-  { \__keys_variable_set:cnnN {#1} { tl } { } x }
+\cs_new_protected:cpn { \c__keys_props_root_str .tl_set_e:N } #1
+  { \__keys_variable_set:NnnN #1 { tl } { } e }
+\cs_new_protected:cpn { \c__keys_props_root_str .tl_set_e:c } #1
+  { \__keys_variable_set:cnnN {#1} { tl } { } e }
 \cs_new_protected:cpn { \c__keys_props_root_str .tl_gset:N } #1
   { \__keys_variable_set:NnnN #1 { tl } { g } n }
 \cs_new_protected:cpn { \c__keys_props_root_str .tl_gset:c } #1
   { \__keys_variable_set:cnnN {#1} { tl } { g } n }
-\cs_new_protected:cpn { \c__keys_props_root_str .tl_gset_x:N } #1
-  { \__keys_variable_set:NnnN #1 { tl } { g } x }
-\cs_new_protected:cpn { \c__keys_props_root_str .tl_gset_x:c } #1
-  { \__keys_variable_set:cnnN {#1} { tl } { g } x }
+\cs_new_protected:cpn { \c__keys_props_root_str .tl_gset_e:N } #1
+  { \__keys_variable_set:NnnN #1 { tl } { g } e }
+\cs_new_protected:cpn { \c__keys_props_root_str .tl_gset_e:c } #1
+  { \__keys_variable_set:cnnN {#1} { tl } { g } e }
 \cs_new_protected:cpn { \c__keys_props_root_str .undefine: }
   { \__keys_undefine: }
 \cs_new_protected:cpn { \c__keys_props_root_str .usage:n } #1
@@ -13514,7 +13653,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \__keys_value_requirement:nn { required } {#1} }
 \cs_new_protected:Npn \keys_set:nn #1#2
   {
-    \use:x
+    \use:e
       {
         \bool_set_false:N \exp_not:N \l__keys_only_known_bool
         \bool_set_false:N \exp_not:N \l__keys_filtered_bool
@@ -13532,12 +13671,12 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           { \exp_not:o \l__keys_relative_tl }
       }
   }
-\cs_generate_variant:Nn \keys_set:nn { nV , nv , no , nx }
+\cs_generate_variant:Nn \keys_set:nn { nV , nv , ne , no , nx }
 \cs_new_protected:Npn \__keys_set:nn #1#2
   { \exp_args:No \__keys_set:nnn \l__keys_module_str {#1} {#2} }
 \cs_new_protected:Npn \__keys_set:nnn #1#2#3
   {
-    \str_set:Nx \l__keys_module_str { \__keys_trim_spaces:n {#2} }
+    \str_set:Ne \l__keys_module_str { \__keys_trim_spaces:n {#2} }
     \keyval_parse:NNn \__keys_set_keyval:n \__keys_set_keyval:nn {#3}
     \str_set:Nn \l__keys_module_str {#1}
   }
@@ -13546,26 +13685,26 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \exp_args:No \__keys_set_known:nnnnN
       \l__keys_unused_clist \q__keys_no_value {#1} {#2} #3
   }
-\cs_generate_variant:Nn \keys_set_known:nnN { nV , nv , no }
+\cs_generate_variant:Nn \keys_set_known:nnN { nV , nv , ne , no }
 \cs_new_protected:Npn \keys_set_known:nnnN #1#2#3#4
   {
     \exp_args:No \__keys_set_known:nnnnN
       \l__keys_unused_clist {#3} {#1} {#2} #4
   }
-\cs_generate_variant:Nn \keys_set_known:nnnN { nV , nv , no }
+\cs_generate_variant:Nn \keys_set_known:nnnN { nV , nv , ne , no }
 \cs_new_protected:Npn \__keys_set_known:nnnnN #1#2#3#4#5
   {
     \clist_clear:N \l__keys_unused_clist
     \__keys_set_known:nnn {#2} {#3} {#4}
-    \__kernel_tl_set:Nx #5 { \exp_not:o \l__keys_unused_clist }
+    \__kernel_tl_set:Ne #5 { \exp_not:o \l__keys_unused_clist }
     \tl_set:Nn \l__keys_unused_clist {#1}
   }
 \cs_new_protected:Npn \keys_set_known:nn #1#2
   { \__keys_set_known:nnn \q__keys_no_value {#1} {#2} }
-\cs_generate_variant:Nn \keys_set_known:nn { nV , nv , no }
+\cs_generate_variant:Nn \keys_set_known:nn { nV , nv , ne , no }
 \cs_new_protected:Npn \__keys_set_known:nnn #1#2#3
   {
-    \use:x
+    \use:e
       {
         \bool_set_true:N \exp_not:N \l__keys_only_known_bool
         \bool_set_false:N \exp_not:N \l__keys_filtered_bool
@@ -13599,7 +13738,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \clist_clear:N \l__keys_unused_clist
     \__keys_set_filter:nnnn {#2} {#3} {#4} {#5}
-    \__kernel_tl_set:Nx #6 { \exp_not:o \l__keys_unused_clist }
+    \__kernel_tl_set:Ne #6 { \exp_not:o \l__keys_unused_clist }
     \tl_set:Nn \l__keys_unused_clist {#1}
   }
 \cs_new_protected:Npn \keys_set_filter:nnn #1#2#3
@@ -13607,7 +13746,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_generate_variant:Nn \keys_set_filter:nnn { nnV , nnv , nno }
 \cs_new_protected:Npn \__keys_set_filter:nnnn #1#2#3#4
   {
-    \use:x
+    \use:e
       {
         \bool_set_false:N \exp_not:N \l__keys_only_known_bool
         \bool_set_true:N \exp_not:N \l__keys_filtered_bool
@@ -13626,7 +13765,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \keys_set_groups:nnn #1#2#3
   {
-    \use:x
+    \use:e
       {
         \bool_set_false:N \exp_not:N \l__keys_only_known_bool
         \bool_set_false:N \exp_not:N \l__keys_filtered_bool
@@ -13673,7 +13812,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__keys_set_keyval:nnn #1#2#3
   {
-    \__kernel_tl_set:Nx \l_keys_path_str
+    \__kernel_tl_set:Ne \l_keys_path_str
       {
         \tl_if_blank:nF {#1}
           { #1 / }
@@ -13703,12 +13842,12 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__keys_find_key_module_auxii:Nw
     #1 #2 \s__keys_mark #3 \s__keys_nil \__keys_find_key_module_auxii:Nw
   {
-    \cs_set_nopar:Npx #1 { \tl_if_empty:NF #1 { #1 / } #2 }
+    \cs_set_nopar:Npe #1 { \tl_if_empty:NF #1 { #1 / } #2 }
     \__keys_find_key_module_auxi:Nw #1 #3 \s__keys_nil \__keys_find_key_module_auxiii:Nw
   }
 \cs_new_protected:Npn \__keys_find_key_module_auxiii:Nw #1 #2 \s__keys_mark
   {
-    \cs_set_nopar:Npx #1 { \tl_if_empty:NF #1 { #1 / } #2 }
+    \cs_set_nopar:Npe #1 { \tl_if_empty:NF #1 { #1 / } #2 }
     \__keys_find_key_module_auxi:Nw #1
   }
 \cs_new_protected:Npn \__keys_find_key_module_auxiv:Nw
@@ -13830,7 +13969,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           { \c__keys_code_root_str \l__keys_module_str / unknown }
           { \__keys_execute:no { \l__keys_module_str / unknown } \l_keys_value_tl }
           {
-            \msg_error:nnxx { keys } { unknown }
+            \msg_error:nnee { keys } { unknown }
               \l_keys_path_str \l__keys_module_str
           }
       }
@@ -13849,7 +13988,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \__keys_quark_if_no_value:NTF \l__keys_relative_tl
       {
-        \clist_put_right:Nx \l__keys_unused_clist
+        \clist_put_right:Ne \l__keys_unused_clist
           {
             \l_keys_key_str
             \bool_if:NF \l__keys_no_value_bool
@@ -13859,7 +13998,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       {
         \tl_if_empty:NTF \l__keys_relative_tl
           {
-            \clist_put_right:Nx \l__keys_unused_clist
+            \clist_put_right:Ne \l__keys_unused_clist
               {
                 \l_keys_path_str
                 \bool_if:NF \l__keys_no_value_bool
@@ -13871,30 +14010,30 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__keys_store_unused_aux:
   {
-    \__kernel_tl_set:Nx \l__keys_relative_tl
+    \__kernel_tl_set:Ne \l__keys_relative_tl
       { \exp_args:No \__keys_trim_spaces:n \l__keys_relative_tl }
-    \use:x
+    \use:e
       {
         \cs_set_protected:Npn \__keys_store_unused:w
-          ####1 \l__keys_relative_tl /
-          ####2 \l__keys_relative_tl /
-          ####3 \s__keys_stop
+          ##1 \l__keys_relative_tl /
+          ##2 \l__keys_relative_tl /
+          ##3 \s__keys_stop
       }
         {
           \tl_if_blank:nF {##1}
             {
-              \msg_error:nnxx { keys } { bad-relative-key-path }
+              \msg_error:nnee { keys } { bad-relative-key-path }
                 \l_keys_path_str
                 \l__keys_relative_tl
             }
-          \clist_put_right:Nx \l__keys_unused_clist
+          \clist_put_right:Ne \l__keys_unused_clist
             {
               \exp_not:n {##2}
               \bool_if:NF \l__keys_no_value_bool
                 { = { \exp_not:o \l_keys_value_tl } }
             }
         }
-    \use:x
+    \use:e
       {
         \__keys_store_unused:w \l_keys_path_str
           \l__keys_relative_tl / \l__keys_relative_tl /
@@ -13989,9 +14128,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { \prg_return_false: }
   }
 \cs_new_protected:Npn \keys_show:nn
-  { \__keys_show:Nnn \msg_show:nnxxxx }
+  { \__keys_show:Nnn \msg_show:nneeee }
 \cs_new_protected:Npn \keys_log:nn
-  { \__keys_show:Nnn \msg_log:nnxxxx }
+  { \__keys_show:Nnn \msg_log:nneeee }
 \cs_new_protected:Npn \__keys_show:Nnn #1#2#3
   {
     #1 { keys } { show-key }
@@ -14014,7 +14153,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
       { } { }
   }
-\cs_new:Npx \__keys_show:n #1
+\cs_new:Npe \__keys_show:n #1
   {
     \exp_not:N \__keys_show:w
       #1
@@ -14023,21 +14162,21 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \tl_to_str:n { \__keys_precompile:n }
       \exp_not:N \s__keys_stop
   }
-\use:x
+\use:e
   {
     \cs_new:Npn \exp_not:N \__keys_show:w
-      ##1 \tl_to_str:n { \__keys_precompile:n }
-      ##2 \tl_to_str:n { \__keys_precompile:n }
-      ##3 \exp_not:N \s__keys_stop
+      #1 \tl_to_str:n { \__keys_precompile:n }
+      #2 \tl_to_str:n { \__keys_precompile:n }
+      #3 \exp_not:N \s__keys_stop
   }
   {
     \tl_if_blank:nTF {#2}
       {#1}
       { \__keys_show:Nw #2 \s__keys_stop }
   }
-\use:x
+\use:e
   {
-    \cs_new:Npn \exp_not:N \__keys_show:Nw ##1##2
+    \cs_new:Npn \exp_not:N \__keys_show:Nw #1#2
       \c_right_brace_str \exp_not:N \s__keys_stop
   }
   {#2}
@@ -14086,6 +14225,22 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \prop_gput:Nnn \g_msg_module_name_prop { keys } { LaTeX }
 \prop_gput:Nnn \g_msg_module_type_prop { keys } { }
+\cs_new_protected:cpn { \c__keys_props_root_str .str_set_x:N } #1
+  { \__keys_variable_set:NnnN #1 { str } { } x }
+\cs_new_protected:cpn { \c__keys_props_root_str .str_set_x:c } #1
+  { \__keys_variable_set:cnnN {#1} { str } { } x }
+\cs_new_protected:cpn { \c__keys_props_root_str .str_gset_x:N } #1
+  { \__keys_variable_set:NnnN #1 { str } { g } x }
+\cs_new_protected:cpn { \c__keys_props_root_str .str_gset_x:c } #1
+  { \__keys_variable_set:cnnN {#1} { str } { g } x }
+\cs_new_protected:cpn { \c__keys_props_root_str .tl_set_x:N } #1
+  { \__keys_variable_set:NnnN #1 { tl } { } x }
+\cs_new_protected:cpn { \c__keys_props_root_str .tl_set_x:c } #1
+  { \__keys_variable_set:cnnN {#1} { tl } { } x }
+\cs_new_protected:cpn { \c__keys_props_root_str .tl_gset_x:N } #1
+  { \__keys_variable_set:NnnN #1 { tl } { g } x }
+\cs_new_protected:cpn { \c__keys_props_root_str .tl_gset_x:c } #1
+  { \__keys_variable_set:cnnN {#1} { tl } { g } x }
 %% File: l3intarray.dtx
 \msg_new:nnn { kernel } { negative-array-size }
   { Size~of~array~may~not~be~negative:~#1 }
@@ -14098,7 +14253,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       {
         \__kernel_chk_if_free_cs:N #1
         \int_gincr:N \g__intarray_table_int
-        \cs_gset_nopar:Npx #1 { \__intarray:w \int_use:N \g__intarray_table_int \c_space_tl }
+        \cs_gset_nopar:Npe #1 { \__intarray:w \int_use:N \g__intarray_table_int \c_space_tl }
       }
     \cs_new_protected:Npn \intarray_new:Nn #1#2
       {
@@ -14106,7 +14261,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \__intarray_gset_count:Nw #1 \int_eval:n {#2} \scan_stop:
         \int_compare:nNnT { \intarray_count:N #1 } < 0
           {
-            \msg_error:nnx { kernel } { negative-array-size }
+            \msg_error:nne { kernel } { negative-array-size }
               { \intarray_count:N #1 }
           }
       }
@@ -14118,7 +14273,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       {
         \__intarray_gset:wF \int_eval:n {#2} #1 \int_eval:n{#3}
           {
-            \msg_error:nnxxx { kernel } { out-of-bounds }
+            \msg_error:nneee { kernel } { out-of-bounds }
               { \token_to_str:N #1 } { \int_use:N \l__intarray_bad_index_int } { \intarray_count:N #1 }
           }
       }
@@ -14182,7 +14337,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \__intarray_count:w #1 = \int_eval:n {#2} \scan_stop:
         \int_compare:nNnT { \intarray_count:N #1 } < 0
           {
-            \msg_error:nnx { kernel } { negative-array-size }
+            \msg_error:nne { kernel } { negative-array-size }
               { \intarray_count:N #1 }
           }
         \int_compare:nNnT { \intarray_count:N #1 } > 0
@@ -14223,7 +14378,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \cs_generate_variant:Nn \intarray_gset:Nnn { c }
     \cs_new_protected:Npn \__intarray_gset:Nww #1#2 ; #3 ;
       {
-        \__intarray_bounds:NNnTF \msg_error:nnxxx #1 {#2}
+        \__intarray_bounds:NNnTF \msg_error:nneee #1 {#2}
           {
             \__intarray_gset_overflow_test:nw {#3}
             \__kernel_intarray_gset:Nnn #1 {#2} {#3}
@@ -14249,7 +14404,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
     \cs_new_protected:Npn \__intarray_gset_overflow:NNnn #1#2#3#4
       {
-        \msg_error:nnxxxx { kernel } { overflow }
+        \msg_error:nneeee { kernel } { overflow }
           { \token_to_str:N #2 } {#3} {#4} {  \__intarray_signed_max_dim:n {#4} }
         #1 #2 {#3} { \__intarray_signed_max_dim:n {#4} }
       }
@@ -14347,9 +14502,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \__intarray_gset_range:Nw #1
       }
   }
-\cs_new_protected:Npn \intarray_show:N { \__intarray_show:NN \msg_show:nnxxxx }
+\cs_new_protected:Npn \intarray_show:N { \__intarray_show:NN \msg_show:nneeee }
 \cs_generate_variant:Nn \intarray_show:N { c }
-\cs_new_protected:Npn \intarray_log:N { \__intarray_show:NN \msg_log:nnxxxx }
+\cs_new_protected:Npn \intarray_log:N { \__intarray_show:NN \msg_log:nneeee }
 \cs_generate_variant:Nn \intarray_log:N { c }
 \cs_new_protected:Npn \__intarray_show:NN #1#2
   {
@@ -14378,7 +14533,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new:Npn \__fp_use_i:ww #1; #2; { #1; }
 \cs_new:Npn \__fp_use_i:www #1; #2; #3; { #1; }
 \cs_new_protected:Npn \__fp_misused:n #1
-  { \msg_error:nnx { fp } { misused } { \fp_to_tl:n {#1} } }
+  { \msg_error:nne { fp } { misused } { \fp_to_tl:n {#1} } }
 \scan_new:N \s__fp
 \cs_new_protected:Npn \__fp_chk:w #1 ;
   { \__fp_misused:n { \s__fp \__fp_chk:w #1 ; } }
@@ -14404,7 +14559,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \int_const:Nn \c__fp_minus_min_exponent_int { 10000 }
 \int_const:Nn \c__fp_max_exponent_int { 10000 }
 \int_const:Nn \c__fp_max_exp_exponent_int { 5 }
-\tl_const:Nx \c__fp_overflowing_fp
+\tl_const:Ne \c__fp_overflowing_fp
   {
     \s__fp \__fp_chk:w 1 0
       { \int_eval:n { \c__fp_max_exponent_int + 1 } }
@@ -14526,7 +14681,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \s__fp { \__fp_type_from_scan_other:N #1 }
       \s__fp_stop
   }
-\cs_new:Npx \__fp_type_from_scan_other:N #1
+\cs_new:Npe \__fp_type_from_scan_other:N #1
   {
     \exp_not:N \exp_after:wN \exp_not:N \__fp_type_from_scan:w
     \exp_not:N \token_to_str:N #1 \s__fp_mark
@@ -14770,11 +14925,11 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           { invalid_operation , division_by_zero , overflow , underflow }
           {#1}
           {
-            \msg_error:nnxx { fp }
+            \msg_error:nnee { fp }
               { unknown-fpu-trap-type } {#1} {#2}
           }
           {
-            \msg_error:nnx
+            \msg_error:nne
               { fp } { unknown-fpu-exception } {#1}
           }
       }
@@ -15344,7 +15499,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \exp_after:wN \__fp_parse_exponent:N
         \exp:w \__fp_parse_expand:w
   }
-\cs_new:Npx \__fp_parse_one_register_aux:Nw #1
+\cs_new:Npe \__fp_parse_one_register_aux:Nw #1
   {
     \exp_not:n
       {
@@ -15928,7 +16083,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \fi:
     \__fp_parse_expand:w
   }
-\cs_new:Npx \__fp_parse_lparen_after:NwN #1#2 @ #3
+\cs_new:Npe \__fp_parse_lparen_after:NwN #1#2 @ #3
   {
     \exp_not:N \token_if_eq_meaning:NNTF #3
       \exp_not:c { __fp_parse_infix_):N }
@@ -16574,11 +16729,11 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \cs_new_eq:NN #1 \c_zero_fp }
 \cs_generate_variant:Nn \fp_new:N {c}
 \cs_new_protected:Npn \fp_set:Nn   #1#2
-  { \__kernel_tl_set:Nx #1 { \exp_not:f { \__fp_parse:n {#2} } } }
+  { \__kernel_tl_set:Ne #1 { \exp_not:f { \__fp_parse:n {#2} } } }
 \cs_new_protected:Npn \fp_gset:Nn  #1#2
-  { \__kernel_tl_gset:Nx #1 { \exp_not:f { \__fp_parse:n {#2} } } }
+  { \__kernel_tl_gset:Ne #1 { \exp_not:f { \__fp_parse:n {#2} } } }
 \cs_new_protected:Npn \fp_const:Nn #1#2
-  { \tl_const:Nx #1 { \exp_not:f { \__fp_parse:n {#2} } } }
+  { \tl_const:Ne #1 { \exp_not:f { \__fp_parse:n {#2} } } }
 \cs_generate_variant:Nn \fp_set:Nn {c}
 \cs_generate_variant:Nn \fp_gset:Nn {c}
 \cs_generate_variant:Nn \fp_const:Nn {c}
@@ -16620,7 +16775,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
             \s__fp \__fp_chk:w ??? ; \s__fp_stop
           }
       }
-      { \exp_args:Nx #1 { \token_to_str:N #2 = \fp_to_tl:N #2 } }
+      { \exp_args:Ne #1 { \token_to_str:N #2 = \fp_to_tl:N #2 } }
   }
 \cs_new:Npn \__fp_show_validate:w
     #1 \s__fp \__fp_chk:w #2#3#4#5 ; #6 \s__fp_stop
@@ -16909,7 +17064,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \int_gincr:N \g__kernel_prg_map_int
     \exp_args:NNc \__fp_step:NNnnnn
-      \cs_gset_protected:Npx
+      \cs_gset_protected:Npe
       { __fp_map_ \int_use:N \g__kernel_prg_map_int :w }
       {#1} {#2} {#3}
       {
@@ -17066,7 +17221,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \__fp_parse_unary_function:NNN \__fp_sign_o:w ? }
 \cs_new:Npn \__fp_parse_word_sqrt:N
   { \__fp_parse_unary_function:NNN \__fp_sqrt_o:w ? }
-\cs_new:cpx { __fp_-_o:ww } \s__fp
+\cs_new:cpe { __fp_-_o:ww } \s__fp
   {
     \exp_not:c { __fp_+_o:ww }
     \exp_not:n { \s__fp \__fp_neg_sign:N }
@@ -17566,11 +17721,11 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     + 5 * #1
     \exp_after:wN \__fp_div_significand_vi:Nw
-    \int_value:w \__fp_int_eval:w -20 + 2*#2#3 - #1*#6#7 +
+    \int_value:w \__fp_int_eval:w -50 + 2*#2#3 - #1*#6#7 +
       \exp_after:wN \__fp_div_significand_v:NN
-      \int_value:w \__fp_int_eval:w 199980 + 2*#4 - #1*#8 +
+      \int_value:w \__fp_int_eval:w 499950 + 2*#4 - #1*#8 +
         \exp_after:wN \__fp_div_significand_v:NN
-        \int_value:w \__fp_int_eval:w 200000 + 2*#5 - #1*#9 ;
+        \int_value:w \__fp_int_eval:w 500000 + 2*#5 - #1*#9 ;
   }
 \cs_new:Npn \__fp_div_significand_v:NN #1#2 { #1#2 \__fp_int_eval_end: + }
 \cs_new:Npn \__fp_div_significand_vi:Nw #1#2;
@@ -19069,13 +19224,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     {cos} {cot} {csc} {sec} {sin} {tan}
   }
   {
-    \cs_new:cpx { __fp_parse_word_#1:N }
+    \cs_new:cpe { __fp_parse_word_#1:N }
       {
         \exp_not:N \__fp_parse_unary_function:NNN
         \exp_not:c { __fp_#1_o:w }
         \exp_not:N \use_i:nn
       }
-    \cs_new:cpx { __fp_parse_word_#1d:N }
+    \cs_new:cpe { __fp_parse_word_#1d:N }
       {
         \exp_not:N \__fp_parse_unary_function:NNN
         \exp_not:c { __fp_#1_o:w }
@@ -19687,7 +19842,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { #1 { acot } { acotd } }
       { \__fp_atan_default:w \__fp_acotii_o:Nww #1 }
   }
-\cs_new:Npx \__fp_atan_default:w #1#2#3 @ { #1 #2 #3 \c_one_fp @ }
+\cs_new:Npe \__fp_atan_default:w #1#2#3 @ { #1 #2 #3 \c_one_fp @ }
 \cs_new:Npn \__fp_atanii_o:Nww
     #1 \s__fp \__fp_chk:w #2#3#4; \s__fp \__fp_chk:w #5 #6 @
   {
@@ -20576,7 +20731,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_generate_variant:Nn \fparray_gset:Nnn { c }
 \cs_new_protected:Npn \__fp_array_gset:NNNNww #1#2#3#4#5 ; #6 ;
   {
-    \__fp_array_bounds:NNnTF \msg_error:nnxxx #4 {#5}
+    \__fp_array_bounds:NNnTF \msg_error:nneee #4 {#5}
       {
         \exp_after:wN \__fp_change_func_type:NNN
           \__fp_use_i_until_s:nw #6 ;
@@ -20837,7 +20992,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       {
         \seq_gpop:NNF \g__cctab_unused_seq \l__cctab_internal_a_tl
           { \__cctab_begin_aux: }
-        \exp_args:Nx \__cctab_chk_group_begin:n
+        \__cctab_chk_group_begin:e
           { \__cctab_nesting_number:N \l__cctab_internal_a_tl }
         \seq_gpush:NV \g__cctab_stack_seq \l__cctab_internal_a_tl
         \exp_args:NV \__cctab_gset:n \l__cctab_internal_a_tl
@@ -20850,7 +21005,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \seq_gpop:NNTF \g__cctab_stack_seq \l__cctab_internal_a_tl
       {
         \seq_gpush:NV \g__cctab_unused_seq \l__cctab_internal_a_tl
-        \exp_args:Nx \__cctab_chk_group_end:n
+        \exp_args:Ne \__cctab_chk_group_end:n
           { \__cctab_nesting_number:N \l__cctab_internal_a_tl }
         \__cctab_select:N \l__cctab_internal_a_tl
       }
@@ -20858,10 +21013,11 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__cctab_chk_group_begin:n #1
   {
-    \seq_gpush:Nx \g__cctab_group_seq
+    \seq_gpush:Ne \g__cctab_group_seq
       { \int_use:N \tex_currentgrouplevel:D }
     \cs_set_eq:cN { __cctab_group_ #1 _chk: } \prg_do_nothing:
   }
+\cs_generate_variant:Nn \__cctab_chk_group_begin:n { e }
 \cs_new_protected:Npn \__cctab_chk_group_end:n #1
   {
     \seq_gpop:NN \g__cctab_group_seq \l__cctab_internal_b_tl
@@ -20872,7 +21028,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
       { \cs_if_exist_p:c { __cctab_group_ #1 _chk: } }
       {
-        \msg_error:nnx { cctab } { group-mismatch }
+        \msg_error:nne { cctab } { group-mismatch }
           {
             \int_sign:n
               { \tex_currentgrouplevel:D - \l__cctab_internal_b_tl }
@@ -20888,10 +21044,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \exp_after:wN \exp_after:wN \exp_after:wN \__cctab_nesting_number:w
           \exp_after:wN \token_to_str:N #1
       }
-    \use:x
+    \use:e
       {
         \cs_new:Npn \exp_not:N \__cctab_nesting_number:w
-          ##1 \tl_to_str:n { g__cctab_ } ##2 \tl_to_str:n { _cctab } {##2}
+          #1 \tl_to_str:n { g__cctab_ } #2 \tl_to_str:n { _cctab } {#2}
       }
   }
 \cs_if_exist:NT \hook_gput_code:nnn
@@ -20930,13 +21086,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \__cctab_chk_if_valid_aux:NTF #1
           { \prg_return_true: }
           {
-            \msg_error:nnx { cctab } { invalid-cctab }
+            \msg_error:nne { cctab } { invalid-cctab }
               { \token_to_str:N #1 }
             \prg_return_false:
           }
       }
       {
-        \msg_error:nnx { kernel } { command-not-defined }
+        \msg_error:nne { kernel } { command-not-defined }
           { \token_to_str:N #1 }
         \prg_return_false:
       }
@@ -21191,7 +21347,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \group_begin:
       \__sort_main:NNNn \tl_map_inline:Nn \tl_map_break:n #2 {#3}
-      \__kernel_tl_gset:Nx \g__sort_internal_tl
+      \__kernel_tl_gset:Ne \g__sort_internal_tl
         { \__sort_tl_toks:w \l__sort_min_int ; }
     \group_end:
     #1 #2 \g__sort_internal_tl
@@ -21232,7 +21388,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \int_step_inline:nnn
         \l__sort_min_int { \l__sort_top_int - 1 }
         {
-          \seq_gput_right:Nx \g__sort_internal_seq
+          \seq_gput_right:Ne \g__sort_internal_seq
             { \tex_the:D \tex_toks:D ##1 }
         }
     \group_end:
@@ -21313,14 +21469,14 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__sort_return_mark:w #1 \s__sort_mark { }
 \cs_new_protected:Npn \__sort_return_none_error:
   {
-    \msg_error:nnxx { sort } { return-none }
+    \msg_error:nnee { sort } { return-none }
       { \tex_the:D \tex_toks:D \l__sort_A_int }
       { \tex_the:D \tex_toks:D \l__sort_C_int }
     \__sort_return_same:w \__sort_return_none_error:
   }
 \cs_new_protected:Npn \__sort_return_two_error:
   {
-    \msg_error:nnxx { sort } { return-two }
+    \msg_error:nnee { sort } { return-two }
       { \tex_the:D \tex_toks:D \l__sort_A_int }
       { \tex_the:D \tex_toks:D \l__sort_C_int }
   }
@@ -21450,7 +21606,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \cs_set_eq:NN \toksdef \__sort_disabled_toksdef:n }
 \cs_new_protected:Npn \__sort_disabled_toksdef:n #1
   {
-    \msg_error:nnx { sort } { toksdef }
+    \msg_error:nne { sort } { toksdef }
       { \token_to_str:N #1 }
     \__sort_error:
     \tex_toksdef:D #1
@@ -21466,7 +21622,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__sort_too_long_error:NNw #1#2 \fi:
   {
     \fi:
-    \msg_error:nnxxx { sort } { too-large }
+    \msg_error:nneee { sort } { too-large }
       { \token_to_str:N #2 }
       { \int_eval:n { \l__sort_true_max_int - \l__sort_min_int } }
       { \int_eval:n { \l__sort_top_int - \l__sort_min_int } }
@@ -21588,12 +21744,12 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \fi:
   }
 \group_begin:
-  \__kernel_tl_set:Nx \l__str_internal_tl { \tl_to_str:n { 0123456789ABCDEF } }
+  \__kernel_tl_set:Ne \l__str_internal_tl { \tl_to_str:n { 0123456789ABCDEF } }
    \tl_map_inline:Nn \l__str_internal_tl
      {
         \tl_map_inline:Nn \l__str_internal_tl
           {
-            \tl_const:cx { c__str_byte_ \int_eval:n {"#1##1} _tl }
+            \tl_const:ce { c__str_byte_ \int_eval:n {"#1##1} _tl }
                { \char_generate:nn { "#1##1 } { 12 } #1 ##1 }
           }
      }
@@ -21633,7 +21789,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__str_convert_gmap:N #1
   {
-    \__kernel_tl_gset:Nx \g__str_result_tl
+    \__kernel_tl_gset:Ne \g__str_result_tl
       {
         \exp_after:wN \__str_convert_gmap_loop:NN
         \exp_after:wN #1
@@ -21649,7 +21805,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__str_convert_gmap_internal:N #1
   {
-    \__kernel_tl_gset:Nx \g__str_result_tl
+    \__kernel_tl_gset:Ne \g__str_result_tl
       {
         \exp_after:wN \__str_convert_gmap_internal_loop:Nww
         \exp_after:wN #1
@@ -21663,13 +21819,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     #1 {#3}
     \__str_convert_gmap_internal_loop:Nww #1
   }
-\cs_new_protected:Npn \__str_if_flag_error:nnx #1
+\cs_new_protected:Npn \__str_if_flag_error:nne #1
   {
     \flag_if_raised:nTF {#1}
-      { \msg_error:nnx { str } }
+      { \msg_error:nne { str } }
       { \use_none:nn }
   }
-\cs_new_protected:Npn \__str_if_flag_no_error:nnx #1#2#3
+\cs_new_protected:Npn \__str_if_flag_no_error:nne #1#2#3
   { \flag_if_raised:nT {#1} { \bool_gset_true:N \g__str_error_bool } }
 \cs_new:Npn \__str_if_flag_times:nT #1#2
   { \flag_if_raised:nT {#1} { #2~(x \flag_height:n {#1} ) } }
@@ -21682,7 +21838,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \bool_gset_false:N \g__str_error_bool
     \__str_convert:nNNnnn
-      { \cs_set_eq:NN \__str_if_flag_error:nnx \__str_if_flag_no_error:nnx }
+      { \cs_set_eq:NN \__str_if_flag_error:nne \__str_if_flag_no_error:nne }
       \tl_set_eq:NN #1 {#2} {#3} {#4}
     \bool_if:NTF \g__str_error_bool \prg_return_false: \prg_return_true:
   }
@@ -21691,7 +21847,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \bool_gset_false:N \g__str_error_bool
     \__str_convert:nNNnnn
-      { \cs_set_eq:NN \__str_if_flag_error:nnx \__str_if_flag_no_error:nnx }
+      { \cs_set_eq:NN \__str_if_flag_error:nne \__str_if_flag_no_error:nne }
       \tl_gset_eq:NN #1 {#2} {#3} {#4}
     \bool_if:NTF \g__str_error_bool \prg_return_false: \prg_return_true:
   }
@@ -21699,7 +21855,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \group_begin:
       #1
-      \__kernel_tl_gset:Nx \g__str_result_tl { \__kernel_str_to_other_fast:n {#4} }
+      \__kernel_tl_gset:Ne \g__str_result_tl { \__kernel_str_to_other_fast:n {#4} }
       \exp_after:wN \__str_convert:wwwnn
         \tl_to_str:n {#5} /// \s__str_stop
         { decode } { unescape }
@@ -21725,7 +21881,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \if_meaning:w #1 #5
       \tl_if_empty:nF {#3}
-        { \msg_error:nnx { str } { native-escaping } {#3} }
+        { \msg_error:nne { str } { native-escaping } {#3} }
       #1
     \else:
       #4 #2 #1
@@ -21735,7 +21891,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \cs_if_exist:cF { __str_convert_#2_#3: }
       {
-        \exp_args:Nx \__str_convert:nnnn
+        \exp_args:Ne \__str_convert:nnnn
           { \__str_convert_lowercase_alphanum:n {#3} }
           {#1} {#2} {#3}
       }
@@ -21757,7 +21913,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
               }
               {
                 \tl_clear:N \l__str_internal_tl
-                \msg_error:nnxx { str } { unknown-#2 } {#4} {#1}
+                \msg_error:nnee { str } { unknown-#2 } {#4} {#1}
               }
           }
         \cs_if_exist:cF { __str_convert_#3_#1: }
@@ -21827,9 +21983,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \cs_new_protected:Npn \__str_convert_unescape_:
       {
         \flag_clear:n { str_byte }
-        \__kernel_tl_gset:Nx \g__str_result_tl
+        \__kernel_tl_gset:Ne \g__str_result_tl
           { \exp_args:No \__str_filter_bytes:n \g__str_result_tl }
-        \__str_if_flag_error:nnx { str_byte } { non-byte } { bytes }
+        \__str_if_flag_error:nne { str_byte } { non-byte } { bytes }
       }
   }
   { \cs_new_protected:Npn \__str_convert_unescape_: { } }
@@ -21856,7 +22012,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       {
         \flag_clear:n { str_error }
         \__str_convert_gmap_internal:N \__str_encode_native_char:n
-        \__str_if_flag_error:nnx { str_error }
+        \__str_if_flag_error:nne { str_error }
           { native-overflow } { }
       }
     \cs_new:Npn \__str_encode_native_char:n #1
@@ -21879,7 +22035,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__str_convert_decode_clist:
   {
     \clist_gset:No \g__str_result_tl \g__str_result_tl
-    \__kernel_tl_gset:Nx \g__str_result_tl
+    \__kernel_tl_gset:Ne \g__str_result_tl
       {
         \exp_args:No \clist_map_function:nN
           \g__str_result_tl \__str_decode_clist_char:n
@@ -21890,7 +22046,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__str_convert_encode_clist:
   {
     \__str_convert_gmap_internal:N \__str_encode_clist_char:n
-    \__kernel_tl_gset:Nx \g__str_result_tl { \tl_tail:N \g__str_result_tl }
+    \__kernel_tl_gset:Ne \g__str_result_tl { \tl_tail:N \g__str_result_tl }
   }
 \cs_new:Npn \__str_encode_clist_char:n #1 { , #1 }
 \cs_new_protected:Npn \__str_declare_eight_bit_encoding:nnnn #1
@@ -21943,14 +22099,14 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__str_convert_decode_eight_bit:n #1
   {
-    \cs_set:Npx \__str_tmp:w
+    \cs_set:Npe \__str_tmp:w
       {
         \exp_not:N \__str_decode_eight_bit_aux:Nn
         \exp_not:c { g__str_decode_#1_intarray }
       }
     \flag_clear:n { str_error }
     \__str_convert_gmap:N \__str_tmp:w
-    \__str_if_flag_error:nnx { str_error } { decode-8-bit } {#1}
+    \__str_if_flag_error:nne { str_error } { decode-8-bit } {#1}
   }
 \cs_new:Npn \__str_decode_eight_bit_aux:Nn #1#2
   {
@@ -21971,7 +22127,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \int_new:N \l__str_modulo_int
 \cs_new_protected:Npn \__str_convert_encode_eight_bit:n #1
   {
-    \cs_set:Npx \__str_tmp:w
+    \cs_set:Npe \__str_tmp:w
       {
         \exp_not:N \__str_encode_eight_bit_aux:NNn
         \exp_not:c { g__str_encode_#1_intarray }
@@ -21979,7 +22135,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
     \flag_clear:n { str_error }
     \__str_convert_gmap_internal:N \__str_tmp:w
-    \__str_if_flag_error:nnx { str_error } { encode-8-bit } {#1}
+    \__str_if_flag_error:nne { str_error } { encode-8-bit } {#1}
   }
 \cs_new:Npn \__str_encode_eight_bit_aux:NNn #1#2#3
   {
@@ -22048,7 +22204,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \group_begin:
       \flag_clear:n { str_error }
       \int_set:Nn \tex_escapechar:D { 92 }
-      \__kernel_tl_gset:Nx \g__str_result_tl
+      \__kernel_tl_gset:Ne \g__str_result_tl
         {
           \__str_output_byte:w "
             \exp_last_unbraced:Nf \__str_unescape_hex_auxi:N
@@ -22057,7 +22213,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
             \prg_break_point:
           \__str_output_end:
         }
-      \__str_if_flag_error:nnx { str_error } { unescape-hex } { }
+      \__str_if_flag_error:nne { str_error } { unescape-hex } { }
     \group_end:
   }
 \cs_new:Npn \__str_unescape_hex_auxi:N #1
@@ -22097,14 +22253,14 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           \flag_clear:n { str_byte }
           \flag_clear:n { str_error }
           \int_set:Nn \tex_escapechar:D { 92 }
-          \__kernel_tl_gset:Nx \g__str_result_tl
+          \__kernel_tl_gset:Ne \g__str_result_tl
             {
               \exp_after:wN #3 \g__str_result_tl
                 #1 ? { ? \prg_break: }
               \prg_break_point:
             }
-          \__str_if_flag_error:nnx { str_byte } { non-byte } { #2 }
-          \__str_if_flag_error:nnx { str_error } { unescape-#2 } { }
+          \__str_if_flag_error:nne { str_byte } { non-byte } { #2 }
+          \__str_if_flag_error:nne { str_error } { unescape-#2 } { }
         \group_end:
       }
     \cs_new:Npn #3 ##1#1##2##3
@@ -22150,20 +22306,20 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
             \flag_clear:n { str_byte }
             \flag_clear:n { str_error }
             \int_set:Nn \tex_escapechar:D { 92 }
-            \__kernel_tl_gset:Nx \g__str_result_tl
+            \__kernel_tl_gset:Ne \g__str_result_tl
               {
                 \exp_after:wN \__str_unescape_string_newlines:wN
                   \g__str_result_tl \prg_break: ^^M ?
                 \prg_break_point:
               }
-            \__kernel_tl_gset:Nx \g__str_result_tl
+            \__kernel_tl_gset:Ne \g__str_result_tl
               {
                 \exp_after:wN \__str_unescape_string_loop:wNNN
                   \g__str_result_tl #1 ?? { ? \prg_break: }
                 \prg_break_point:
               }
-            \__str_if_flag_error:nnx { str_byte } { non-byte } { string }
-            \__str_if_flag_error:nnx { str_error } { unescape-string } { }
+            \__str_if_flag_error:nne { str_byte } { non-byte } { string }
+            \__str_if_flag_error:nne { str_error } { unescape-string } { }
           \group_end:
         }
     }
@@ -22254,7 +22410,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \fi:
     \fi:
   }
-\str_const:Nx \c__str_escape_string_str
+\str_const:Ne \c__str_escape_string_str
   { \c_backslash_str ( ) }
 \cs_new_protected:Npn \__str_convert_escape_string:
   { \__str_convert_gmap:N \__str_escape_string_char:N }
@@ -22389,13 +22545,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \flag_clear:n { str_extra }
     \flag_clear:n { str_overlong }
     \flag_clear:n { str_overflow }
-    \__kernel_tl_gset:Nx \g__str_result_tl
+    \__kernel_tl_gset:Ne \g__str_result_tl
       {
         \exp_after:wN \__str_decode_utf_viii_start:N \g__str_result_tl
           { \prg_break: \__str_decode_utf_viii_end: }
         \prg_break_point:
       }
-    \__str_if_flag_error:nnx { str_error } { utf8-decode } { }
+    \__str_if_flag_error:nne { str_error } { utf8-decode } { }
   }
 \cs_new:Npn \__str_decode_utf_viii_start:N #1
   {
@@ -22481,7 +22637,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   \cs_new_protected:cpn { __str_convert_encode_utf16: }
     {
       \__str_encode_utf_xvi_aux:N \__str_output_byte_pair_be:n
-      \tl_gput_left:Nx \g__str_result_tl { ^^fe ^^ff }
+      \tl_gput_left:Ne \g__str_result_tl { ^^fe ^^ff }
     }
   \cs_new_protected:cpn { __str_convert_encode_utf16be: }
     { \__str_encode_utf_xvi_aux:N \__str_output_byte_pair_be:n }
@@ -22492,7 +22648,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \flag_clear:n { str_error }
       \cs_set_eq:NN \__str_tmp:w #1
       \__str_convert_gmap_internal:N \__str_encode_utf_xvi_char:n
-      \__str_if_flag_error:nnx { str_error } { utf16-encode } { }
+      \__str_if_flag_error:nne { str_error } { utf16-encode } { }
     }
   \cs_new:Npn \__str_encode_utf_xvi_char:n #1
     {
@@ -22589,13 +22745,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \flag_clear:n { str_extra }
       \flag_clear:n { str_end }
       \cs_set:Npn \__str_tmp:w ##1 ##2 { ` ## #1 }
-      \__kernel_tl_gset:Nx \g__str_result_tl
+      \__kernel_tl_gset:Ne \g__str_result_tl
         {
           \exp_after:wN \__str_decode_utf_xvi_pair:NN
             #2 \q__str_nil \q__str_nil
           \prg_break_point:
         }
-      \__str_if_flag_error:nnx { str_error } { utf16-decode } { }
+      \__str_if_flag_error:nne { str_error } { utf16-decode } { }
     }
   \cs_new:Npn \__str_decode_utf_xvi_pair:NN #1#2
     {
@@ -22664,7 +22820,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   \cs_new_protected:cpn { __str_convert_encode_utf32: }
     {
       \__str_convert_gmap_internal:N \__str_encode_utf_xxxii_be:n
-      \tl_gput_left:Nx \g__str_result_tl { ^^00 ^^00 ^^fe ^^ff }
+      \tl_gput_left:Ne \g__str_result_tl { ^^00 ^^00 ^^fe ^^ff }
     }
   \cs_new_protected:cpn { __str_convert_encode_utf32be: }
     { \__str_convert_gmap_internal:N \__str_encode_utf_xxxii_be:n }
@@ -22746,13 +22902,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \flag_clear:n { str_end }
       \flag_clear:n { str_error }
       \cs_set:Npn \__str_tmp:w ##1 ##2 { ` ## #1 }
-      \__kernel_tl_gset:Nx \g__str_result_tl
+      \__kernel_tl_gset:Ne \g__str_result_tl
         {
           \exp_after:wN \__str_decode_utf_xxxii_loop:NNNN
             #2 \s__str_stop \s__str_stop \s__str_stop \s__str_stop
           \prg_break_point:
         }
-      \__str_if_flag_error:nnx { str_error } { utf32-decode } { }
+      \__str_if_flag_error:nne { str_error } { utf32-decode } { }
     }
   \cs_new:Npn \__str_decode_utf_xxxii_loop:NNNN #1#2#3#4
     {
@@ -22811,7 +22967,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
     \cs_new:Npn \__str_convert_pdfname_bytes_aux:n #1
       { \__str_convert_pdfname_bytes_aux:nnnn #1 }
-    \cs_new:Npx \__str_convert_pdfname_bytes_aux:nnnn #1#2#3#4
+    \cs_new:Npe \__str_convert_pdfname_bytes_aux:nnnn #1#2#3#4
       {
         \c_hash_str \exp_not:N \__str_output_hexadecimal:n {#1}
         \c_hash_str \exp_not:N \__str_output_hexadecimal:n {#2}
@@ -22834,7 +22990,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \tl_new:N \l__tl_peek_code_tl
 \group_begin:
 \char_set_active_eq:NN \  \scan_stop:
-\tl_const:Nx \c__tl_peek_catcodes_tl
+\tl_const:Ne \c__tl_peek_catcodes_tl
   {
     \char_generate:nn { 32 } { 3 }   3
     \char_generate:nn { 32 } { 4 }   4
@@ -23042,7 +23198,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__tl_analysis_b:n #1
   {
-    \__kernel_tl_gset:Nx \g__tl_analysis_result_tl
+    \__kernel_tl_gset:Ne \g__tl_analysis_result_tl
       {
         \__tl_analysis_b_loop:w 0; #1
         \prg_break_point:
@@ -23074,7 +23230,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \fi:
     #3 #1; #2;
   }
-\cs_new:Npx \__tl_analysis_b_char:Nn #1#2
+\cs_new:Npe \__tl_analysis_b_char:Nn #1#2
   {
     \exp_not:N \if_meaning:w #2 \exp_not:N \tex_undefined:D
       \token_to_str:N D \exp_not:N \else:
@@ -23180,9 +23336,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \__tl_analysis_map:NwNw #1
   }
 \cs_new_protected:Npn \tl_analysis_show:N
-  { \__tl_analysis_show:NNN \msg_show:nnxxxx \tl_show:N }
+  { \__tl_analysis_show:NNN \msg_show:nneeee \tl_show:N }
 \cs_new_protected:Npn \tl_analysis_log:N
-  { \__tl_analysis_show:NNN \msg_log:nnxxxx \tl_log:N }
+  { \__tl_analysis_show:NNN \msg_log:nneeee \tl_log:N }
 \cs_new_protected:Npn \__tl_analysis_show:NNN #1#2#3
   {
     \tl_if_exist:NTF #3
@@ -23194,9 +23350,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { #2 #3 }
   }
 \cs_new_protected:Npn \tl_analysis_show:n
-  { \__tl_analysis_show:Nn \msg_show:nnxxxx }
+  { \__tl_analysis_show:Nn \msg_show:nneeee }
 \cs_new_protected:Npn \tl_analysis_log:n
-  { \__tl_analysis_show:Nn \msg_log:nnxxxx }
+  { \__tl_analysis_show:Nn \msg_log:nneeee }
 \cs_new_protected:Npn \__tl_analysis_show:Nn #1#2
   {
     \__tl_analysis:n {#2}
@@ -23304,7 +23460,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__tl_peek_analysis_loop:NNn #1#2#3
   {
     \group_begin:
-    \tl_set:Nx \l__tl_peek_code_tl
+    \tl_set:Ne \l__tl_peek_code_tl
       {
         \exp_not:c
           { __tl_analysis_map_ \int_use:N \g__kernel_prg_map_int :nnN }
@@ -23333,7 +23489,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__tl_peek_analysis_exp:N #1
   {
-    \cs_set_nopar:Npx \l__tl_peek_code_tl
+    \cs_set_nopar:Npe \l__tl_peek_code_tl
       {
         \tex_let:D \exp_not:N #1 \scan_stop:
         \exp_not:o \l__tl_peek_code_tl
@@ -23355,7 +23511,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
     \l__tl_peek_code_tl
   }
-\cs_new:Npx \__tl_peek_analysis_exp_active:N #1
+\cs_new:Npe \__tl_peek_analysis_exp_active:N #1
   { { \exp_not:N \int_value:w `#1 } \token_to_str:N D }
 \cs_new_protected:Npn \__tl_peek_analysis_nonexp:N #1
   {
@@ -23373,7 +23529,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \l__tl_peek_code_tl { \exp_not:n {#1} } { -1 } 0 }
 \group_begin:
 \char_set_active_eq:NN \ \scan_stop:
-\cs_new_protected:Npx \__tl_peek_analysis_char:N #1
+\cs_new_protected:Npe \__tl_peek_analysis_char:N #1
   {
     \cs_set_eq:NN
       \char_generate:nn { 32 } { 13 }
@@ -23381,7 +23537,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \tex_lccode:D `#1 = 32 \exp_stop_f:
     \tex_lowercase:D
       {
-        \tl_put_right:Nx \exp_not:N \l__tl_peek_code_tl
+        \tl_put_right:Ne \exp_not:N \l__tl_peek_code_tl
           { \exp_not:n { \__tl_analysis_b_char:Nn \use_none:n } {#1} }
       }
     \exp_not:n
@@ -23460,7 +23616,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__tl_peek_analysis_active_str:n #1
   {
-    \tl_put_right:Nx \l__tl_peek_code_tl
+    \tl_put_right:Ne \l__tl_peek_code_tl
       {
         { \char_generate:nn { `#1 } { 13 } }
         { \int_value:w `#1 }
@@ -23470,7 +23626,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__tl_peek_analysis_explicit:n #1
   {
-    \tl_put_right:Nx \l__tl_peek_code_tl
+    \tl_put_right:Ne \l__tl_peek_code_tl
       {
         \if_meaning:w \l_peek_token \c_space_token
           { ~ } { 32 } \token_to_str:N A
@@ -23529,7 +23685,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__tl_peek_analysis_collect_end:NNN #1#2#3
   {
     #1 #2
-    \tl_put_right:Nx \l__tl_peek_code_tl
+    \tl_put_right:Ne \l__tl_peek_code_tl
       {
         { \exp_not:N \exp_not:n { \exp_not:c { \l__tl_internal_a_tl } } }
         { -1 }
@@ -23537,7 +23693,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
     \l__tl_peek_code_tl
   }
-\tl_const:Nx \c__tl_analysis_show_etc_str % (
+\tl_const:Ne \c__tl_analysis_show_etc_str % (
   { \token_to_str:N \ETC.) }
 \msg_new:nnn { tl } { show-analysis }
   {
@@ -23565,15 +23721,15 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \int_incr:N #2
       }
   }
-\cs_new_protected:Npn \__regex_toks_put_left:Nx #1#2
+\cs_new_protected:Npn \__regex_toks_put_left:Ne #1#2
   {
-    \cs_set_nopar:Npx \__regex_tmp:w { #2 }
+    \cs_set_nopar:Npe \__regex_tmp:w { #2 }
     \tex_toks:D #1 \exp_after:wN \exp_after:wN \exp_after:wN
       { \exp_after:wN \__regex_tmp:w \tex_the:D \tex_toks:D #1 }
   }
-\cs_new_protected:Npn \__regex_toks_put_right:Nx #1#2
+\cs_new_protected:Npn \__regex_toks_put_right:Ne #1#2
   {
-    \cs_set_nopar:Npx \__regex_tmp:w {#2}
+    \cs_set_nopar:Npe \__regex_tmp:w {#2}
     \tex_toks:D #1 \exp_after:wN
       { \tex_the:D \tex_toks:D \exp_after:wN #1 \__regex_tmp:w }
   }
@@ -23736,7 +23892,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \int_compare:nNnTF \l__regex_curr_catcode_int = 0
       {
-        \__kernel_tl_set:Nx \l__regex_internal_a_tl
+        \__kernel_tl_set:Ne \l__regex_internal_a_tl
           { \scan_stop: \__regex_curr_cs_to_str: \scan_stop: }
         \tl_if_in:noTF { \scan_stop: #1 \scan_stop: }
           \l__regex_internal_a_tl
@@ -23754,7 +23910,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           \__regex_build_for_cs:n {#1}
           \bool_set_eq:NN \l__regex_saved_success_bool
             \g__regex_success_bool
-          \exp_args:Nx \__regex_match_cs:n { \__regex_curr_cs_to_str: }
+          \exp_args:Ne \__regex_match_cs:n { \__regex_curr_cs_to_str: }
           \if_meaning:w \c_true_bool \g__regex_success_bool
             \group_insert_after:N \__regex_break_true:w
           \fi:
@@ -23846,9 +24002,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \cs_set:Npn \__regex_escape_escaped:N ##1 { #2 }
       \cs_set:Npn \__regex_escape_raw:N ##1 { #3 }
       \__regex_standard_escapechar:
-      \__kernel_tl_gset:Nx \g__regex_internal_tl
+      \__kernel_tl_gset:Ne \g__regex_internal_tl
         { \__kernel_str_to_other_fast:n {#4} }
-      \tl_put_right:Nx \l__regex_internal_a_tl
+      \tl_put_right:Ne \l__regex_internal_a_tl
         {
           \exp_after:wN \__regex_escape_loop:N \g__regex_internal_tl
           \scan_stop: \prg_break_point:
@@ -23880,17 +24036,17 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \prg_break:
   }
 \cs_new:cpn { __regex_escape_~:w } { }
-\cs_new:cpx { __regex_escape_/a:w }
+\cs_new:cpe { __regex_escape_/a:w }
   { \exp_not:N \__regex_escape_raw:N \iow_char:N \^^G }
-\cs_new:cpx { __regex_escape_/t:w }
+\cs_new:cpe { __regex_escape_/t:w }
   { \exp_not:N \__regex_escape_raw:N \iow_char:N \^^I }
-\cs_new:cpx { __regex_escape_/n:w }
+\cs_new:cpe { __regex_escape_/n:w }
   { \exp_not:N \__regex_escape_raw:N \iow_char:N \^^J }
-\cs_new:cpx { __regex_escape_/f:w }
+\cs_new:cpe { __regex_escape_/f:w }
   { \exp_not:N \__regex_escape_raw:N \iow_char:N \^^L }
-\cs_new:cpx { __regex_escape_/r:w }
+\cs_new:cpe { __regex_escape_/r:w }
   { \exp_not:N \__regex_escape_raw:N \iow_char:N \^^M }
-\cs_new:cpx { __regex_escape_/e:w }
+\cs_new:cpe { __regex_escape_/e:w }
   { \exp_not:N \__regex_escape_raw:N \iow_char:N \^^[ }
 \cs_new:cpn { __regex_escape_/x:w } \__regex_escape_loop:N
   {
@@ -24185,7 +24341,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         }
         { }
       \if_int_compare:w \l__regex_group_level_int > \c_zero_int
-        \msg_error:nnx { regex } { missing-rparen }
+        \msg_error:nne { regex } { missing-rparen }
           { \int_use:N \l__regex_group_level_int }
         \prg_replicate:nn
           { \l__regex_group_level_int }
@@ -24204,7 +24360,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \fi:
       \tl_build_put_right:Nn \l__regex_build_tl { \if_false: { \fi: } }
       \tl_build_end:N \l__regex_build_tl
-      \exp_args:NNNx
+      \exp_args:NNNe
     \group_end:
     \tl_set:Nn \l__regex_internal_regex { \l__regex_build_tl }
   }
@@ -24269,7 +24425,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \tl_build_put_right:Nn \l__regex_build_tl
           { \__regex_class:NnnnN \c_true_bool { \if_false: } \fi: }
       }
-    \tl_build_put_right:Nx \l__regex_build_tl
+    \tl_build_put_right:Ne \l__regex_build_tl
       {
         \if_int_compare:w \l__regex_catcodes_int <
           \c__regex_all_catcodes_int
@@ -24284,13 +24440,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__regex_compile_abort_tokens:n #1
   {
-    \use:x
+    \use:e
       {
         \exp_args:No \tl_map_function:nN { \tl_to_str:n {#1} }
           \__regex_compile_raw:N
       }
   }
-\cs_generate_variant:Nn \__regex_compile_abort_tokens:n { x }
+\cs_generate_variant:Nn \__regex_compile_abort_tokens:n { e }
 \cs_new_protected:Npn \__regex_compile_if_quantifier:TFw #1#2#3#4
   {
     \token_if_eq_meaning:NNTF #3 \__regex_compile_special:N
@@ -24312,11 +24468,11 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \tl_build_put_right:Nn \l__regex_build_tl
       { \if_false: { \fi: } { 1 } { 0 } \c_false_bool }
   }
-\cs_new_protected:Npn \__regex_compile_quantifier_abort:xNN #1#2#3
+\cs_new_protected:Npn \__regex_compile_quantifier_abort:eNN #1#2#3
   {
     \__regex_compile_quantifier_none:
-    \msg_warning:nnxx { regex } { invalid-quantifier } {#1} {#3}
-    \__regex_compile_abort_tokens:x {#1}
+    \msg_warning:nnee { regex } { invalid-quantifier } {#1} {#3}
+    \__regex_compile_abort_tokens:e {#1}
     #2 #3
   }
 \cs_new_protected:Npn \__regex_compile_quantifier_lazyness:nnNN #1#2#3#4
@@ -24342,7 +24498,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \__regex_get_digits:NTFw \l__regex_internal_a_int
       { \__regex_compile_quantifier_braced_auxi:w }
-      { \__regex_compile_quantifier_abort:xNN { \c_left_brace_str } }
+      { \__regex_compile_quantifier_abort:eNN { \c_left_brace_str } }
   }
 \cs_new_protected:Npn \__regex_compile_quantifier_braced_auxi:w #1#2
   {
@@ -24361,7 +24517,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           }
       }
       {
-        \__regex_compile_quantifier_abort:xNN
+        \__regex_compile_quantifier_abort:eNN
           { \c_left_brace_str \int_use:N \l__regex_internal_a_int }
         #1 #2
       }
@@ -24374,7 +24530,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           { \int_use:N \l__regex_internal_a_int } { -1 }
       }
       {
-        \__regex_compile_quantifier_abort:xNN
+        \__regex_compile_quantifier_abort:eNN
           { \c_left_brace_str \int_use:N \l__regex_internal_a_int , }
         #1 #2
       }
@@ -24385,7 +24541,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       {
         \if_int_compare:w \l__regex_internal_a_int >
           \l__regex_internal_b_int
-          \msg_error:nnxx { regex } { backwards-quantifier }
+          \msg_error:nnee { regex } { backwards-quantifier }
             { \int_use:N \l__regex_internal_a_int }
             { \int_use:N \l__regex_internal_b_int }
           \int_zero:N \l__regex_internal_b_int
@@ -24397,7 +24553,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           { \int_use:N \l__regex_internal_b_int }
       }
       {
-        \__regex_compile_quantifier_abort:xNN
+        \__regex_compile_quantifier_abort:eNN
           {
             \c_left_brace_str
             \int_use:N \l__regex_internal_a_int ,
@@ -24408,7 +24564,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__regex_compile_raw_error:N #1
   {
-    \msg_error:nnx { regex } { bad-escape } {#1}
+    \msg_error:nne { regex } { bad-escape } {#1}
     \__regex_compile_raw:N #1
   }
 \cs_new_protected:Npn \__regex_compile_raw:N #1#2#3
@@ -24450,9 +24606,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \__regex_if_end_range:NNTF #2 #3
       {
         \if_int_compare:w `#1 > `#3 \exp_stop_f:
-          \msg_error:nnxx { regex } { range-backwards } {#1} {#3}
+          \msg_error:nnee { regex } { range-backwards } {#1} {#3}
         \else:
-          \tl_build_put_right:Nx \l__regex_build_tl
+          \tl_build_put_right:Ne \l__regex_build_tl
             {
               \if_int_compare:w `#1 = `#3 \exp_stop_f:
                 \__regex_item_equal:n
@@ -24464,9 +24620,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \fi:
       }
       {
-        \msg_warning:nnxx { regex } { range-missing-end }
+        \msg_warning:nnee { regex } { range-missing-end }
           {#1} { \c_backslash_str #3 }
-        \tl_build_put_right:Nx \l__regex_build_tl
+        \tl_build_put_right:Ne \l__regex_build_tl
           {
             \__regex_item_equal:n { \int_value:w `#1 \exp_stop_f: }
             \__regex_item_equal:n { \int_value:w `- \exp_stop_f: }
@@ -24474,7 +24630,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         #2#3
       }
   }
-\cs_new_protected:cpx { __regex_compile_.: }
+\cs_new_protected:cpe { __regex_compile_.: }
   {
     \exp_not:N \__regex_if_in_class:TF
       { \__regex_compile_raw:N . }
@@ -24488,9 +24644,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_set_protected:Npn \__regex_tmp:w #1#2
   {
-    \cs_new_protected:cpx { __regex_compile_/#1: }
+    \cs_new_protected:cpe { __regex_compile_/#1: }
       { \__regex_compile_one:n \exp_not:c { __regex_prop_#1: } }
-    \cs_new_protected:cpx { __regex_compile_/#2: }
+    \cs_new_protected:cpe { __regex_compile_/#2: }
       {
         \__regex_compile_one:n
           { \__regex_item_reverse:n { \exp_not:c { __regex_prop_#1: } } }
@@ -24534,8 +24690,8 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           }
       }
   }
-\exp_args:Nx \__regex_tmp:w { \iow_char:N \^ } { \__regex_A_test: }
-\exp_args:Nx \__regex_tmp:w { \iow_char:N \$ } { \__regex_Z_test: }
+\exp_args:Ne \__regex_tmp:w { \iow_char:N \^ } { \__regex_A_test: }
+\exp_args:Ne \__regex_tmp:w { \iow_char:N \$ } { \__regex_Z_test: }
 \cs_new_protected:cpn { __regex_compile_]: }
   {
     \__regex_if_in_class:TF
@@ -24609,11 +24765,11 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           {
             : { \__regex_compile_class_posix:NNNNw }
             = {
-                \msg_warning:nnx { regex }
+                \msg_warning:nne { regex }
                   { posix-unsupported } { = }
               }
             . {
-                \msg_warning:nnx { regex }
+                \msg_warning:nne { regex }
                   { posix-unsupported } { . }
               }
           }
@@ -24625,12 +24781,12 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \__regex_two_if_eq:NNNNTF #5 #6 \__regex_compile_special:N ^
       {
         \bool_set_false:N \l__regex_internal_bool
-        \__kernel_tl_set:Nx \l__regex_internal_a_tl { \if_false: } \fi:
+        \__kernel_tl_set:Ne \l__regex_internal_a_tl { \if_false: } \fi:
           \__regex_compile_class_posix_loop:w
       }
       {
         \bool_set_true:N \l__regex_internal_bool
-        \__kernel_tl_set:Nx \l__regex_internal_a_tl { \if_false: } \fi:
+        \__kernel_tl_set:Ne \l__regex_internal_a_tl { \if_false: } \fi:
           \__regex_compile_class_posix_loop:w #5 #6
       }
   }
@@ -24655,9 +24811,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
               }
           }
           {
-            \msg_warning:nnx { regex } { posix-unknown }
+            \msg_warning:nne { regex } { posix-unknown }
               { \l__regex_internal_a_tl }
-            \__regex_compile_abort_tokens:x
+            \__regex_compile_abort_tokens:e
               {
                 [: \bool_if:NF \l__regex_internal_bool { ^ }
                 \l__regex_internal_a_tl :]
@@ -24665,9 +24821,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           }
       }
       {
-        \msg_error:nnxx { regex } { posix-missing-close }
+        \msg_error:nnee { regex } { posix-missing-close }
           { [: \l__regex_internal_a_tl } { #2 #4 }
-        \__regex_compile_abort_tokens:x { [: \l__regex_internal_a_tl }
+        \__regex_compile_abort_tokens:e { [: \l__regex_internal_a_tl }
         #1 #2 #3 #4
       }
   }
@@ -24687,7 +24843,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \if_int_compare:w \l__regex_group_level_int > \c_zero_int
         \tl_build_put_right:Nn \l__regex_build_tl { \if_false: { \fi: } }
         \tl_build_end:N \l__regex_build_tl
-        \exp_args:NNNx
+        \exp_args:NNNe
       \group_end:
       \tl_build_put_right:Nn \l__regex_build_tl { \l__regex_build_tl }
       \int_set_eq:NN \l__regex_catcodes_int \l__regex_default_catcodes_int
@@ -24717,7 +24873,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \cs_if_exist_use:cF
           { __regex_compile_special_group_\token_to_str:N #4 :w }
           {
-            \msg_warning:nnx { regex } { special-group-unknown }
+            \msg_warning:nne { regex } { special-group-unknown }
               { (? #4 }
             \__regex_compile_group_begin:N \__regex_group:nnnN
               \__regex_compile_raw:N ? #3 #4
@@ -24755,7 +24911,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           { \__regex_item_caseless_range:nn }
       }
       {
-        \msg_warning:nnx { regex } { unknown-option } { (?i #2 }
+        \msg_warning:nne { regex } { unknown-option } { (?i #2 }
         \__regex_compile_raw:N (
         \__regex_compile_raw:N ?
         \__regex_compile_raw:N i
@@ -24774,7 +24930,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           { \__regex_item_caseful_range:nn }
       }
       {
-        \msg_warning:nnx { regex } { unknown-option } { (?-#2#4 }
+        \msg_warning:nne { regex } { unknown-option } { (?-#2#4 }
         \__regex_compile_raw:N (
         \__regex_compile_raw:N ?
         \__regex_compile_raw:N -
@@ -24802,7 +24958,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
       { \cs_if_exist_use:cF { __regex_compile_c_#2:w } }
           {
-            \msg_error:nnx { regex } { c-missing-category } {#2}
+            \msg_error:nne { regex } { c-missing-category } {#2}
             #1 #2
           }
   }
@@ -24854,7 +25010,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           { \__regex_compile_c_lbrack_end: }
       }
           {
-            \msg_error:nnx { regex } { c-missing-rbrack } {#2}
+            \msg_error:nne { regex } { c-missing-rbrack } {#2}
             \__regex_compile_c_lbrack_end:
             #1 #2
           }
@@ -24901,12 +25057,12 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \__regex_compile_end:
     \flag_clear:n { __regex_cs }
-    \__kernel_tl_set:Nx \l__regex_internal_a_tl
+    \__kernel_tl_set:Ne \l__regex_internal_a_tl
       {
         \exp_after:wN \__regex_compile_cs_aux:Nn \l__regex_internal_regex
         \q__regex_nil \q__regex_nil \q__regex_recursion_stop
       }
-    \exp_args:Nx \__regex_compile_one:n
+    \exp_args:Ne \__regex_compile_one:n
       {
         \flag_if_raised:nTF { __regex_cs }
           { \__regex_item_cs:n { \exp_not:o \l__regex_internal_regex } }
@@ -24970,7 +25126,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \__regex_two_if_eq:NNNNTF #2 #3 \__regex_compile_special:N \c_left_brace_str
       {
         \tl_set:Nn \l__regex_internal_b_tl {#1}
-        \__kernel_tl_set:Nx \l__regex_internal_a_tl { \if_false: } \fi:
+        \__kernel_tl_set:Ne \l__regex_internal_a_tl { \if_false: } \fi:
         \__regex_compile_u_loop:NN
       }
       {
@@ -25001,7 +25157,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           }
           {
             \if_false: { \fi: }
-            \msg_error:nnx { regex } { u-missing-rbrace } {#2}
+            \msg_error:nne { regex } { u-missing-rbrace } {#2}
             \l__regex_internal_b_tl
             #1 #2
           }
@@ -25012,7 +25168,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \group_begin:
       \cs_set:Npn \__regex_group:nnnN { \__regex_group_no_capture:nnnN }
       \cs_set:Npn \__regex_group_resetting:nnnN { \__regex_group_no_capture:nnnN }
-      \exp_args:NNx
+      \exp_args:NNe
     \group_end:
     \__regex_compile_ur:n { \use:c { \l__regex_internal_a_tl } }
   }
@@ -25055,12 +25211,12 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__regex_compile_u_in_cs:
   {
-    \__kernel_tl_gset:Nx \g__regex_internal_tl
+    \__kernel_tl_gset:Ne \g__regex_internal_tl
       {
         \exp_args:No \__kernel_str_to_other_fast:n
           { \l__regex_internal_a_tl }
       }
-    \tl_build_put_right:Nx \l__regex_build_tl
+    \tl_build_put_right:Ne \l__regex_build_tl
       {
         \tl_map_function:NN \g__regex_internal_tl
           \__regex_compile_u_in_cs_aux:n
@@ -25076,7 +25232,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \tl_analysis_map_inline:Nn \l__regex_internal_a_tl
       {
-        \tl_build_put_right:Nx \l__regex_build_tl
+        \tl_build_put_right:Ne \l__regex_build_tl
           {
             \__regex_class:NnnnN \c_true_bool
               {
@@ -25322,7 +25478,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__regex_show_one:n #1
   {
     \int_incr:N \l__regex_show_lines_int
-    \tl_build_put_right:Nx \l__regex_build_tl
+    \tl_build_put_right:Ne \l__regex_build_tl
       {
         \exp_not:N \iow_newline:
         \seq_map_function:NN \l__regex_show_prefix_seq \use:n
@@ -25330,7 +25486,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
   }
 \cs_new_protected:Npn \__regex_show_push:n #1
-  { \seq_put_right:Nx \l__regex_show_prefix_seq { #1 ~ } }
+  { \seq_put_right:Ne \l__regex_show_prefix_seq { #1 ~ } }
 \cs_new_protected:Npn \__regex_show_pop:
   { \seq_pop_right:NN \l__regex_show_prefix_seq \l__regex_internal_a_tl }
 \cs_new_protected:Npn \__regex_show_scope:nn #1#2
@@ -25380,7 +25536,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
                 \bool_if:NTF #1 { Match } { Don't~match }
                 \__regex_msg_repeated:nnN {#3} {#4} #5
               }
-            \tl_build_put_right:Nx \l__regex_build_tl
+            \tl_build_put_right:Ne \l__regex_build_tl
               { \exp_not:o \l__regex_internal_a_tl }
           }
       }
@@ -25443,7 +25599,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \__regex_case_build_aux:Nn \c_true_bool {#1}
     \int_gzero:N \g__regex_case_int
   }
-\cs_generate_variant:Nn \__regex_case_build:n { x }
+\cs_generate_variant:Nn \__regex_case_build:n { e }
 \cs_new_protected:Npn \__regex_case_build_aux:Nn #1#2
   {
     \__regex_standard_escapechar:
@@ -25454,7 +25610,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { \__regex_action_start_wildcard:N #1 }
     %
     \__regex_build_new_state:
-    \__regex_toks_put_left:Nx \l__regex_left_state_int
+    \__regex_toks_put_left:Ne \l__regex_left_state_int
       { \__regex_action_submatch:nN { 0 } < }
     \__regex_push_lr_states:
     \int_zero:N \l__regex_case_max_group_int
@@ -25478,7 +25634,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
     \seq_pop:NN \l__regex_right_state_seq \l__regex_internal_a_tl
     \int_set:Nn \l__regex_right_state_int \l__regex_internal_a_tl
-    \__regex_toks_put_left:Nx \l__regex_right_state_int
+    \__regex_toks_put_left:Ne \l__regex_right_state_int
       {
         \__regex_action_submatch:nN { 0 } >
         \int_gset:Nn \g__regex_case_int
@@ -25520,9 +25676,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \int_set:Nn \l__regex_right_state_int \l__regex_internal_a_tl
   }
 \cs_new_protected:Npn \__regex_build_transition_left:NNN #1#2#3
-  { \__regex_toks_put_left:Nx  #2 { #1 { \int_eval:n { #3 - #2 } } } }
+  { \__regex_toks_put_left:Ne  #2 { #1 { \int_eval:n { #3 - #2 } } } }
 \cs_new_protected:Npn \__regex_build_transition_right:nNn #1#2#3
-  { \__regex_toks_put_right:Nx #2 { #1 { \int_eval:n { #3 - #2 } } } }
+  { \__regex_toks_put_right:Ne #2 { #1 { \int_eval:n { #3 - #2 } } } }
 \cs_new_protected:Npn \__regex_build_new_state:
   {
     \__regex_toks_clear:N \l__regex_max_state_int
@@ -25533,7 +25689,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__regex_build_transitions_lazyness:NNNNN #1#2#3#4#5
   {
     \__regex_build_new_state:
-    \__regex_toks_put_right:Nx \l__regex_left_state_int
+    \__regex_toks_put_right:Ne \l__regex_left_state_int
       {
         \if_meaning:w \c_true_bool #1
           #2 { \int_eval:n { #3 - \l__regex_left_state_int } }
@@ -25546,7 +25702,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__regex_class:NnnnN #1#2#3#4#5
   {
-    \cs_set:Npx \__regex_tests_action_cost:n ##1
+    \cs_set:Npe \__regex_tests_action_cost:n ##1
       {
         \exp_not:n { \exp_not:n {#2} }
         \bool_if:NTF #1
@@ -25672,8 +25828,8 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__regex_group_submatches:nNN #1#2#3
   {
     \if_int_compare:w #1 > - \c_one_int
-      \__regex_toks_put_left:Nx #2 { \__regex_action_submatch:nN {#1} < }
-      \__regex_toks_put_left:Nx #3 { \__regex_action_submatch:nN {#1} > }
+      \__regex_toks_put_left:Ne #2 { \__regex_action_submatch:nN {#1} < }
+      \__regex_toks_put_left:Ne #3 { \__regex_action_submatch:nN {#1} > }
     \fi:
   }
 \cs_new_protected:Npn \__regex_group_repeat_aux:n #1
@@ -25764,7 +25920,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__regex_assertion:Nn #1#2
   {
     \__regex_build_new_state:
-    \__regex_toks_put_right:Nx \l__regex_left_state_int
+    \__regex_toks_put_right:Ne \l__regex_left_state_int
       {
         \exp_not:n {#2}
         \__regex_break_point:TF
@@ -25809,7 +25965,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__regex_command_K:
   {
     \__regex_build_new_state:
-    \__regex_toks_put_right:Nx \l__regex_left_state_int
+    \__regex_toks_put_right:Ne \l__regex_left_state_int
       {
         \__regex_action_submatch:nN { 0 } <
         \bool_set_true:N \l__regex_fresh_thread_bool
@@ -25904,7 +26060,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \fi:
     \int_set_eq:NN \l__regex_start_pos_int \l__regex_success_pos_int
     \bool_set_false:N \l__regex_match_success_bool
-    \tl_set:Nx \l__regex_curr_submatches_tl
+    \tl_set:Ne \l__regex_curr_submatches_tl
       { \prg_replicate:nn { 2 * \l__regex_capturing_group_int } { 0 , } }
     \int_set_eq:NN \l__regex_max_thread_int \l__regex_min_thread_int
     \__regex_store_state:n { \l__regex_min_state_int }
@@ -25954,10 +26110,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \tl_set:Nn \l__regex_curr_token_tl {#1}
     \int_set:Nn \l__regex_curr_char_int {#2}
     \int_set:Nn \l__regex_curr_catcode_int { "#3 }
-    \tl_build_put_right:Nx \l__regex_matched_analysis_tl
+    \tl_build_put_right:Ne \l__regex_matched_analysis_tl
       { \exp_not:o \l__regex_curr_analysis_tl }
     \tl_set:Nn \l__regex_curr_analysis_tl { { {#1} {#2} #3 } }
-    \use:x
+    \use:e
       {
         \int_set_eq:NN \l__regex_max_thread_int \l__regex_min_thread_int
         \int_step_function:nnN
@@ -26017,7 +26173,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \__regex_action_free_aux:nn { < \l__regex_step_int } }
 \cs_new_protected:Npn \__regex_action_free_aux:nn #1#2
   {
-    \use:x
+    \use:e
       {
         \int_add:Nn \l__regex_curr_state_int {#2}
         \exp_not:n
@@ -26037,7 +26193,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__regex_action_cost:n #1
   {
-    \exp_args:Nx \__regex_store_state:n
+    \exp_args:Ne \__regex_store_state:n
       { \int_eval:n { \l__regex_curr_state_int + #1 } }
   }
 \cs_new_protected:Npn \__regex_store_state:n #1
@@ -26069,7 +26225,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__regex_action_submatch_aux:w #1 ; #2#3
   {
-    \tl_set:Nx \l__regex_curr_submatches_tl
+    \tl_set:Ne \l__regex_curr_submatches_tl
       {
         \prg_replicate:nn
           { #2 \if_meaning:w > #3 + \l__regex_capturing_group_int \fi: }
@@ -26180,25 +26336,25 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         {#2}
       \prg_do_nothing: \prg_do_nothing:
       \if_int_compare:w \l__regex_replacement_csnames_int > \c_zero_int
-        \msg_error:nnx { regex } { replacement-missing-rbrace }
+        \msg_error:nne { regex } { replacement-missing-rbrace }
           { \int_use:N \l__regex_replacement_csnames_int }
-        \tl_build_put_right:Nx \l__regex_build_tl
+        \tl_build_put_right:Ne \l__regex_build_tl
           { \prg_replicate:nn \l__regex_replacement_csnames_int \cs_end: }
       \fi:
       \seq_if_empty:NF \l__regex_replacement_category_seq
         {
-          \msg_error:nnx { regex } { replacement-missing-rparen }
+          \msg_error:nne { regex } { replacement-missing-rparen }
             { \seq_count:N \l__regex_replacement_category_seq }
           \seq_clear:N \l__regex_replacement_category_seq
         }
-      \tl_gput_right:Nx \g__regex_balance_tl
+      \tl_gput_right:Ne \g__regex_balance_tl
         { + \int_use:N \l__regex_balance_int }
       \tl_build_end:N \l__regex_build_tl
       \exp_args:NNo
     \group_end:
     #1 \l__regex_build_tl
   }
-\cs_generate_variant:Nn \__regex_replacement:n { x }
+\cs_generate_variant:Nn \__regex_replacement:n { e }
 \cs_new_protected:Npn \__regex_replacement_set:n #1
   {
     \cs_set:Npn \__regex_replacement_do_one_match:n ##1
@@ -26239,7 +26395,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \exp_args:No \__regex_replacement_set:n
       { \g__regex_case_replacement_tl \fi: }
   }
-\cs_generate_variant:Nn \__regex_case_replacement:n { x }
+\cs_generate_variant:Nn \__regex_case_replacement:n { e }
 \cs_new_protected:Npn \__regex_case_replacement_aux:n #1
   {
     \tl_gput_right:Nn \g__regex_case_replacement_tl { \or: #1 }
@@ -26505,7 +26661,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \group_end:
 \cs_new_protected:Npn \__regex_replacement_error:NNN #1#2#3
   {
-    \msg_error:nnx { regex } { replacement-#1 } {#3}
+    \msg_error:nne { regex } { replacement-#1 } {#3}
     #2 #3
   }
 \cs_new_protected:Npn \regex_new:N #1
@@ -26527,10 +26683,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \regex_const:Nn #1#2
   {
     \__regex_compile:n {#2}
-    \tl_const:Nx #1 { \exp_not:o \l__regex_internal_regex }
+    \tl_const:Ne #1 { \exp_not:o \l__regex_internal_regex }
   }
-\cs_new_protected:Npn \regex_show:n { \__regex_show:Nn \msg_show:nnxxxx }
-\cs_new_protected:Npn \regex_log:n { \__regex_show:Nn \msg_log:nnxxxx }
+\cs_new_protected:Npn \regex_show:n { \__regex_show:Nn \msg_show:nneeee }
+\cs_new_protected:Npn \regex_log:n { \__regex_show:Nn \msg_log:nneeee }
 \cs_new_protected:Npn \__regex_show:Nn #1#2
   {
     \__regex_compile:n {#2}
@@ -26539,8 +26695,8 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { \tl_to_str:n {#2} } { }
       { \l__regex_internal_a_tl } { }
   }
-\cs_new_protected:Npn \regex_show:N { \__regex_show:NN \msg_show:nnxxxx }
-\cs_new_protected:Npn \regex_log:N { \__regex_show:NN \msg_log:nnxxxx }
+\cs_new_protected:Npn \regex_show:N { \__regex_show:NN \msg_show:nneeee }
+\cs_new_protected:Npn \regex_log:N { \__regex_show:NN \msg_log:nneeee }
 \cs_new_protected:Npn \__regex_show:NN #1#2
   {
     \__kernel_chk_tl_type:NnnT #2 { regex }
@@ -26611,15 +26767,15 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \int_if_odd:nTF { \tl_count:n {#1} }
       {
-        \msg_error:nnxxxx { regex } { case-odd }
+        \msg_error:nneeee { regex } { case-odd }
           { \token_to_str:N \regex_replace_case_once:nN(TF) } { code }
           { \tl_count:n {#1} } { \tl_to_str:n {#1} }
         \use_ii:nn
       }
       {
         \__regex_replace_once_aux:nnN
-          { \__regex_case_build:x { \__regex_tl_odd_items:n {#1} } }
-          { \__regex_replacement:x { \tl_item:nn {#1} { 2 * \g__regex_case_int } } }
+          { \__regex_case_build:e { \__regex_tl_odd_items:n {#1} } }
+          { \__regex_replacement:e { \tl_item:nn {#1} { 2 * \g__regex_case_int } } }
           #2
         \bool_if:NTF \g__regex_success_bool
       }
@@ -26634,15 +26790,15 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \int_if_odd:nTF { \tl_count:n {#1} }
       {
-        \msg_error:nnxxxx { regex } { case-odd }
+        \msg_error:nneeee { regex } { case-odd }
           { \token_to_str:N \regex_replace_case_all:nN(TF) } { code }
           { \tl_count:n {#1} } { \tl_to_str:n {#1} }
         \use_ii:nn
       }
       {
         \__regex_replace_all_aux:nnN
-          { \__regex_case_build:x { \__regex_tl_odd_items:n {#1} } }
-          { \__regex_case_replacement:x { \__regex_tl_even_items:n {#1} } }
+          { \__regex_case_build:e { \__regex_tl_odd_items:n {#1} } }
+          { \__regex_case_replacement:e { \__regex_tl_even_items:n {#1} } }
           #2
         \bool_if:NTF \g__regex_success_bool
       }
@@ -26708,14 +26864,14 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \int_if_odd:nTF { \tl_count:n {#1} }
       {
-        \msg_error:nnxxxx { regex } { case-odd }
+        \msg_error:nneeee { regex } { case-odd }
           { \token_to_str:N \regex_match_case:nn(TF) } { code }
           { \tl_count:n {#1} } { \tl_to_str:n {#1} }
         \use_ii:nn
       }
       {
         \__regex_if_match:nn
-          { \__regex_case_build:x { \__regex_tl_odd_items:n {#1} } }
+          { \__regex_case_build:e { \__regex_tl_odd_items:n {#1} } }
           {#2}
         \bool_if:NTF \g__regex_success_bool
       }
@@ -26797,7 +26953,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \flag_clear:n { __regex_begin }
       \flag_clear:n { __regex_end }
       \cs_set_eq:NN \__regex_tmp:w \scan_stop:
-      \__kernel_tl_gset:Nx \g__regex_internal_tl
+      \__kernel_tl_gset:Ne \g__regex_internal_tl
         {
           \int_step_function:nnN { \l__regex_min_submatch_int }
             { \l__regex_submatch_int - 1 } \__regex_extract_seq_aux:n
@@ -26808,12 +26964,12 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \int_set:Nn \l__regex_added_end_int
         { \flag_height:n { __regex_end } }
       \tex_afterassignment:D \__regex_extract_check:w
-      \__kernel_tl_gset:Nx \g__regex_internal_tl
+      \__kernel_tl_gset:Ne \g__regex_internal_tl
         { \g__regex_internal_tl \if_false: { \fi: } }
       \int_compare:nNnT
         { \l__regex_added_begin_int + \l__regex_added_end_int } > 0
         {
-          \msg_error:nnxxx { regex } { result-unbalanced }
+          \msg_error:nneee { regex } { result-unbalanced }
             { splitting~or~extracting~submatches }
             { \int_use:N \l__regex_added_begin_int }
             { \int_use:N \l__regex_added_end_int }
@@ -26872,7 +27028,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \int_incr:N \l__regex_added_begin_int
         \int_incr:N \l__regex_added_end_int
         \tex_afterassignment:D \__regex_extract_check:w
-        \__kernel_tl_gset:Nx \g__regex_internal_tl
+        \__kernel_tl_gset:Ne \g__regex_internal_tl
           {
             \exp_after:wN \__regex_extract_check_loop:w
             \g__regex_internal_tl
@@ -26949,7 +27105,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
             \__regex_replacement_balance_one_match:n
               { \l__regex_zeroth_submatch_int }
           }
-        \__kernel_tl_set:Nx \l__regex_internal_a_tl
+        \__kernel_tl_set:Ne \l__regex_internal_a_tl
           {
             \__regex_replacement_do_one_match:n
               { \l__regex_zeroth_submatch_int }
@@ -26983,7 +27139,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
             { \l__regex_submatch_int - 1 }
             \__regex_replacement_balance_one_match:n
         }
-      \__kernel_tl_set:Nx \l__regex_internal_a_tl
+      \__kernel_tl_set:Ne \l__regex_internal_a_tl
         {
           \int_step_function:nnnN
             { \l__regex_min_submatch_int }
@@ -27004,7 +27160,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \__regex_group_end_replace_try:
     \int_compare:nNnT { \l__regex_added_begin_int + \l__regex_added_end_int } > 0
       {
-        \msg_error:nnxxx { regex } { result-unbalanced }
+        \msg_error:nneee { regex } { result-unbalanced }
           { replacing } { \int_use:N \l__regex_added_begin_int }
           { \int_use:N \l__regex_added_end_int }
       }
@@ -27014,7 +27170,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__regex_group_end_replace_try:
   {
     \tex_afterassignment:D \__regex_group_end_replace_check:w
-    \__kernel_tl_gset:Nx \g__regex_internal_tl
+    \__kernel_tl_gset:Ne \g__regex_internal_tl
       {
         \prg_replicate:nn { \l__regex_added_begin_int } { { \if_false: } \fi: }
         \l__regex_internal_a_tl
@@ -27167,7 +27323,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \cs_set_eq:NN \__regex_replacement_exp_not:N \__regex_peek_replacement_token:n
         \cs_set_eq:NN \__regex_replacement_exp_not:V \__regex_peek_replacement_var:N
         \exp_args:No \__regex_replacement:n { \l__regex_replacement_tl }
-        \use:x
+        \use:e
           {
             \exp_not:n { \exp_after:wN \l__regex_peek_true_tl \exp:w }
             \__regex_replacement_do_one_match:n
@@ -27226,7 +27382,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \exp_after:wN #1
     \exp:w
   }
-\use:x
+\use:e
   {
     \msg_new:nnn { regex } { trailing-backslash }
       { Trailing~'\iow_char:N\\'~in~regex~or~replacement. }
@@ -27533,14 +27689,14 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
   }
 \cs_new_protected:Npn \__regex_trace_push:nnN #1#2#3
-  { \__regex_trace:nnx {#1} {#2} { entering~ \token_to_str:N #3 } }
+  { \__regex_trace:nne {#1} {#2} { entering~ \token_to_str:N #3 } }
 \cs_new_protected:Npn \__regex_trace_pop:nnN #1#2#3
-   { \__regex_trace:nnx {#1} {#2} { leaving~ \token_to_str:N #3 } }
-\cs_new_protected:Npn \__regex_trace:nnx #1#2#3
+   { \__regex_trace:nne {#1} {#2} { leaving~ \token_to_str:N #3 } }
+\cs_new_protected:Npn \__regex_trace:nne #1#2#3
   {
     \int_compare:nNnF
       { \int_use:c { g__regex_trace_#1_int } } < {#2}
-      { \iow_term:x { Trace:~#3 } }
+      { \iow_term:e { Trace:~#3 } }
   }
 \int_new:N \g__regex_trace_regex_int
 \cs_new_protected:Npn \__regex_trace_states:n #1
@@ -27549,7 +27705,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \l__regex_min_state_int
       { \l__regex_max_state_int - 1 }
       {
-        \__regex_trace:nnx { regex } {#1}
+        \__regex_trace:nne { regex } {#1}
           { \iow_char:N \\toks ##1 = { \__regex_toks_use:w ##1 } }
       }
   }
@@ -27698,7 +27854,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \group_end:
       }
       {
-        \msg_error:nnx { kernel } { variable-not-defined }
+        \msg_error:nne { kernel } { variable-not-defined }
           { \token_to_str:N #2 }
       }
   }
@@ -28389,7 +28545,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_generate_variant:Nn \exp_last_unbraced:Nf { c }
 \cs_new_protected:Npn \__color_convert:nnnN #1#2#3#4
   {
-    \tl_set:Nx #4
+    \tl_set:Ne #4
       {
         \cs_if_exist_use:cTF { __color_convert_ #1 _ #2 :w }
           { #3 \s__color_stop }
@@ -28463,11 +28619,11 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \tl_new:N \l__color_value_tl
 \tl_new:N \l__color_next_model_tl
 \tl_new:N \l__color_next_value_tl
-\cs_new_protected:Npx \__color_parse:nN #1#2
+\cs_new_protected:Npe \__color_parse:nN #1#2
   {
-    \tl_set:Nx \exp_not:c { l__color_named_ . _tl }
+    \tl_set:Ne \exp_not:c { l__color_named_ . _tl }
       { \exp_not:N \__color_model:N \exp_not:N \l__color_current_tl }
-    \prop_put:NVx \exp_not:c { l__color_named_ . _prop }
+    \prop_put:NVe \exp_not:c { l__color_named_ . _prop }
       \exp_not:c { l__color_named_ . _tl }
       { \exp_not:N \__color_values:N \exp_not:N \l__color_current_tl }
     \exp_not:N \exp_args:Ne \exp_not:N \__color_parse_aux:nN
@@ -28492,14 +28648,14 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \prop_get:cnNTF
       { l__color_named_ #3 _prop } {#1}
       \l__color_value_tl
-      { \tl_set:Nx #2 { {#1} { \l__color_value_tl } } }
+      { \tl_set:Ne #2 { {#1} { \l__color_value_tl } } }
       {
         \tl_set_eq:Nc \l__color_model_tl { l__color_named_ #3 _tl }
         \prop_get:cVN { l__color_named_ #3 _prop } \l__color_model_tl
           \l__color_value_tl
          \__color_convert:nnN
            \l__color_model_tl {#1} \l__color_value_tl
-        \tl_set:Nx #2
+        \tl_set:Ne #2
           {
             {#1}
             { \l__color_value_tl }
@@ -28524,7 +28680,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \group_begin:
       \__color_extract:nNN {#2} \l__color_model_tl \l__color_value_tl
       \__color_parse_loop:w #3 ! ! ! ! \s__color_stop
-      \tl_set:Nx \l__color_internal_tl
+      \tl_set:Ne \l__color_internal_tl
         { { \l__color_model_tl } { \l__color_value_tl } }
     \exp_args:NNNV \group_end:
     \tl_set:Nn #1 \l__color_internal_tl
@@ -28537,7 +28693,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           { \fp_compare_p:nNn {#1} > { 0 } }
           { \fp_compare_p:nNn {#1} < { 100 } }
           {
-            \use:x
+            \use:e
               {
                 \__color_parse_loop:nn {#1}
                   { \tl_if_blank:nTF {#2} { white } {#2} }
@@ -28577,7 +28733,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
               { \__color_parse_gray:n {#2} }
               { \__color_parse_std:n {#2} }
           }
-        \tl_set:Nx \l__color_value_tl
+        \tl_set:Ne \l__color_value_tl
           {
             \__color_parse_mix:NVVn
               \l__color_model_tl \l__color_value_tl \l__color_next_value_tl {#1}
@@ -28848,7 +29004,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
             \__color_convert:VVN \l__color_model_tl \l_color_fixed_model_tl
               \l__color_value_tl
           }
-        \tl_set:Nx #1
+        \tl_set:Ne #1
           { { \l_color_fixed_model_tl } { \l__color_value_tl } }
       }
   }
@@ -28857,12 +29013,12 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \tl_set:Nn \l__color_model_tl {#1}
     \tl_set:Nn \l__color_value_tl {#2}
   }
-\cs_new_protected:Npx \__color_finalise_current:
+\cs_new_protected:Npe \__color_finalise_current:
   {
-    \tl_set:Nx \exp_not:c { l__color_named_ . _tl }
+    \tl_set:Ne \exp_not:c { l__color_named_ . _tl }
       { \exp_not:N \__color_model:N \exp_not:N \l__color_current_tl }
     \prop_clear:N \exp_not:c { l__color_named_ . _prop }
-    \prop_put:NVx \exp_not:c { l__color_named_ . _prop }
+    \prop_put:NVe \exp_not:c { l__color_named_ . _prop }
       \exp_not:c { l__color_named_ . _tl }
       { \exp_not:N \__color_values:N \exp_not:N \l__color_current_tl }
   }
@@ -28903,7 +29059,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \cs_if_exist:cTF { __color_parse_model_ #1 :w }
       {
-        \tl_set:Nx #3
+        \tl_set:Ne #3
           { \use:c { __color_parse_model_ #1 :w } #2 , 0 , 0 , 0 , 0 \s__color_stop }
       }
       { \msg_error:nnn { color } { unknown-model } {#1} }
@@ -28911,7 +29067,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__color_select_swap:Nnn #1#2#3
   {
     \__color_convert:nVnN {#2} \l_color_fixed_model_tl {#3} \l__color_value_tl
-    \tl_set:Nx #1
+    \tl_set:Ne #1
       { { \l_color_fixed_model_tl } { \l__color_value_tl } }
   }
 \tl_new:N \l_color_math_active_tl
@@ -29059,10 +29215,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       {
         \__color_parse:nN {#2} \l__color_named_tl
         \tl_clear_new:c { l__color_named_ #1 _tl }
-        \tl_set:cx { l__color_named_ #1 _tl }
+        \tl_set:ce { l__color_named_ #1 _tl }
           { \__color_model:N \l__color_named_tl }
         \prop_clear_new:c { l__color_named_ #1 _prop }
-        \prop_put:cvx { l__color_named_ #1 _prop } { l__color_named_ #1 _tl }
+        \prop_put:cve { l__color_named_ #1 _prop } { l__color_named_ #1 _tl }
           { \__color_values:N \l__color_named_tl }
         \__color_set:nnw {#1} {#2} #2 ! \s__color_stop
       }
@@ -29081,7 +29237,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
                   \__color_parse:nN {#2} \l__color_internal_tl
                 \exp_args:NNNV \group_end:
                 \tl_set:Nn \l__color_internal_tl \l__color_internal_tl
-                \prop_put:cxx { l__color_named_ #1 _prop }
+                \prop_put:cee { l__color_named_ #1 _prop }
                   { \__color_model:N \l__color_internal_tl }
                   { \__color_values:N \l__color_internal_tl }
               }
@@ -29098,16 +29254,16 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           {#1} {#3}
       }
   }
-\cs_new_protected:Npx \__color_set_aux:nnn #1#2#3
+\cs_new_protected:Npe \__color_set_aux:nnn #1#2#3
   {
     \exp_not:N \__color_set_colon:nnw {#2} {#3}
       #1 \c_colon_str \c_colon_str \exp_not:N \s__color_stop
   }
-\use:x
+\use:e
   {
     \cs_new_protected:Npn \exp_not:N \__color_set_colon:nnw
-      ##1##2 ##3 \c_colon_str ##4 \c_colon_str
-      ##5 \exp_not:N \s__color_stop
+      #1#2 #3 \c_colon_str #4 \c_colon_str
+      #5 \exp_not:N \s__color_stop
   }
   {
     \tl_if_blank:nTF {#4}
@@ -29121,10 +29277,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \tl_if_blank:nF {#2}
       {
         \__color_select:nnN {#2} {#4} \l__color_named_tl
-        \tl_set:Nx \l__color_internal_tl { \__color_model:N \l__color_named_tl }
+        \tl_set:Ne \l__color_internal_tl { \__color_model:N \l__color_named_tl }
         \tl_if_empty:cT { l__color_named_ #1 _tl }
           { \tl_set_eq:cN { l__color_named_ #1 _tl } \l__color_internal_tl }
-        \prop_put:cVx { l__color_named_ #1 _prop } \l__color_internal_tl
+        \prop_put:cVe { l__color_named_ #1 _prop } \l__color_internal_tl
           { \__color_values:N \l__color_named_tl }
         \__color_set_loop:nw {#1} #3 \s__color_mark #5 \s__color_stop
       }
@@ -29137,9 +29293,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \prop_clear_new:c { l__color_named_ #1 _prop }
         \str_if_eq:nnTF {#2} { . }
           {
-            \tl_set:cx { l__color_named_ #1 _tl }
+            \tl_set:ce { l__color_named_ #1 _tl }
               { \__color_model:N \l__color_current_tl }
-            \prop_put:cvx { l__color_named_ #1 _prop } { l__color_named_ #1 _tl }
+            \prop_put:cve { l__color_named_ #1 _prop } { l__color_named_ #1 _tl }
               { \__color_values:N \l__color_current_tl }
           }
           {
@@ -29161,7 +29317,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \color_set:nnn { blue }  { rgb } { 0 , 0 , 1 }
 \prop_new:c { l__color_named_._prop }
 \tl_new:c { l__color_named_._tl }
-\tl_set:cx { l__color_named_._tl } { \__color_model:N \l__color_current_tl }
+\tl_set:ce { l__color_named_._tl } { \__color_model:N \l__color_current_tl }
 \cs_new_protected:Npn \color_export:nnN #1#2#3
   {
     \group_begin:
@@ -29209,7 +29365,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \group_begin:
   \cs_set_protected:Npn \__color_tmp:w #1#2
     {
-      \cs_new_protected:cpx { __color_export_format_ #1 :nnN } ##1##2##3
+      \cs_new_protected:cpe { __color_export_format_ #1 :nnN } ##1##2##3
         {
           \exp_not:N \__color_export:nnnNN {#2} {##1} {##2} ##3
             \exp_not:c { __color_export_ #1 :Nw }
@@ -29228,10 +29384,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:cpn { __color_export_space-sep-cmyk:Nw } #1#2 \s__color_stop
   { \tl_set:Nn #1 {#2} }
 \cs_new_protected:cpn { __color_export_comma-sep-rgb:Nw } #1#2 ~ #3 ~ #4 \s__color_stop
-  { \tl_set:Nx #1 { #2 , #3 , #4 } }
+  { \tl_set:Ne #1 { #2 , #3 , #4 } }
 \cs_new_protected:Npn \__color_export_HTML:Nw #1#2 ~ #3 ~ #4 \s__color_stop
   {
-    \tl_set:Nx #1
+    \tl_set:Ne #1
       {
         \__color_export_HTML:n {#2}
         \__color_export_HTML:n {#3}
@@ -29312,13 +29468,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \int_gincr:N \g__color_model_int
     \clist_map_inline:nn { fill , stroke , select }
       {
-        \cs_new_protected:cpx { __color_backend_ ##1 _ #1 :n } ####1
+        \cs_new_protected:cpe { __color_backend_ ##1 _ #1 :n } ####1
           {
             \exp_not:c { __color_backend_ ##1 _ #2 :nn }
               { color \int_use:N \g__color_model_int } {####1}
           }
       }
-    \cs_new_protected:cpx { __color_model_ #1 _white: }
+    \cs_new_protected:cpe { __color_model_ #1 _white: }
       {
         \prop_put:Nnn \exp_not:N \l__color_named_white_prop {#1}
           { \exp_not:n {#3} }
@@ -29327,7 +29483,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
     \use:c { __color_model_ #1 _white: }
   }
-\cs_generate_variant:Nn \__color_model_init:nnn { nnx }
+\cs_generate_variant:Nn \__color_model_init:nnn { nne }
 \cs_new_protected:Npn \__color_model_separation:n #1
   {
     \prop_get:NnNTF \l__color_internal_prop { name }
@@ -29384,7 +29540,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \use:c { __color_model_separation_ #8 :nnnnnn }
       {#6} {#7} {#1} {#2} {#3} {#4}
     \prop_gput:Nnn \g__color_alternative_model_prop {#6} {#8}
-    \prop_gput:Nnx \g__color_colorants_prop {#6}
+    \prop_gput:Nne \g__color_colorants_prop {#6}
       { \str_convert_pdfname:n {#7} }
   }
 \cs_new_protected:Npn \__color_model_separation_cmyk:nnnnnn #1#2#3#4#5#6
@@ -29427,7 +29583,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__color_model_convert:nnn #1#2#3
   {
-    \cs_new:cpx { __color_convert_ #1 _ #3 :w } ##1 \s__color_stop
+    \cs_new:cpe { __color_convert_ #1 _ #3 :w } ##1 \s__color_stop
       {
         \exp_not:N \exp_args:NNe \exp_not:N \use:nn
         \exp_not:c { __color_convert_  #2 _ #3 :w }
@@ -29514,12 +29670,12 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__color_model_devicen:nnn #1#2#3
   {
-    \exp_args:Nx \__color_model_devicen:nnnn
+    \exp_args:Ne \__color_model_devicen:nnnn
       { \clist_count:n {#2} } {#1} {#2} {#3}
   }
 \cs_new_protected:Npn \__color_model_devicen:nnnn #1#2#3#4
   {
-    \__color_model_init:nnx {#4} { devicen }
+    \__color_model_init:nne {#4} { devicen }
       {
         0 \prg_replicate:nn { #1 - 1 } { ~ 0 }
       }
@@ -29527,7 +29683,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       { \__color_model_devicen_parse_generic:nn }
         {#4} {#1}
     \__color_model_devicen_init:nnn {#1} {#2} {#3}
-    \__color_model_devicen_convert:nnnx {#4} {#2} {#3}
+    \__color_model_devicen_convert:nnne {#4} {#2} {#3}
       {
         1 \prg_replicate:nn { #1 - 1 } { ~ 1 }
       }
@@ -29584,7 +29740,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         {#1}
         { \__color_model_devicen_parse:nw {#2} ##1 , ##2 , \q_nil , \s__color_stop }
       }
-    \cs_new:cpx { __color_parse_mix_ #1 :nw }
+    \cs_new:cpe { __color_parse_mix_ #1 :nw }
       ##1 ##2 \s__color_mark ##3 \s__color_stop
       {
         \exp_not:N \__color_model_devicen_mix:nw {##1}
@@ -29630,7 +29786,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__color_model_devicen_init:nnnn #1#2#3#4
   {
-    \tl_set:Nx \l__color_internal_tl
+    \tl_set:Ne \l__color_internal_tl
       { \prg_replicate:nn {#1} { 1.0 ~ }   }
     \int_zero:N \l__color_internal_int
     \clist_map_inline:nn {#4}
@@ -29641,7 +29797,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \exp_after:wN \__color_model_devicen_transform:w
           \l__color_value_tl , 0 , 0 , 0 , \s__color_stop {#1} {#2}
       }
-    \tl_put_right:Nx \l__color_internal_tl
+    \tl_put_right:Ne \l__color_internal_tl
       {
         \prg_replicate:nn {#1}
           { neg ~ 1.0 ~ add ~ #1 ~ -1 ~ roll ~ }
@@ -29649,7 +29805,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \prg_replicate:nn {#2} { ~ pop } ~
         #1 ~ 1 ~ roll
       }
-    \use:x
+    \use:e
       {
         \__color_backend_devicen_init:nnn
           {
@@ -29687,7 +29843,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__color_model_devicen_transform:nnn #1#2#3
   {
-    \tl_put_right:Nx \l__color_internal_tl
+    \tl_put_right:Ne \l__color_internal_tl
       {
         \fp_compare:nNnF {#3} = \c_zero_fp
           {
@@ -29705,7 +29861,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \use:c { __color_model_devicen_convert_ #2 :nnn } {#1} {#3}
   }
-\cs_generate_variant:Nn \__color_model_devicen_convert:nnnn { nnnx }
+\cs_generate_variant:Nn \__color_model_devicen_convert:nnnn { nnne }
 \cs_new_protected:Npn \__color_model_devicen_convert_cmyk:nnn #1#2
   {
     \tl_const:cn { c__color_fallback_ #1 _tl } { cmyk }
@@ -29724,7 +29880,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__color_model_devicen_convert:nnnnn #1#2#3#4#5
   {
     \cs_new:cpn { __color_convert_ #2 _ #1 :w } ##1 \s__color_stop {#5}
-    \cs_new:cpx { __color_convert_ #1 _ #2 :w } ##1 \s__color_stop
+    \cs_new:cpe { __color_convert_ #1 _ #2 :w } ##1 \s__color_stop
       {
         \exp_not:c { __color_convert_devicen_ #2 : \prg_replicate:nn {#3} { n } w }
           \prg_replicate:nn {#3} { { 1 } }
@@ -29861,7 +30017,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__color_model_iccbased:nn #1#2
   {
-    \exp_args:NNx \prop_get:NnNTF \c__color_icc_colorspace_signatures_prop
+    \prop_get:NeNTF \c__color_icc_colorspace_signatures_prop
       { \file_hex_dump:nnn { #1 } { 17 } { 20 } } \l__color_internal_tl
       {
         \exp_last_unbraced:NV \__color_model_iccbased_aux:nnnnnn
@@ -29879,7 +30035,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \cs_new:cpn { __color_convert_ #5 _gray:w } ##1 \s__color_stop { 0 }
     \cs_new:cpn { __color_convert_gray_ #5 :w } ##1 \s__color_stop { #2 }
     \use:c { __color_model_devicen_parse_ #1 :nn } {#5} {#1}
-    \exp_args:Nx \__color_backend_iccbased_init:nnn
+    \exp_args:Ne \__color_backend_iccbased_init:nnn
       { \file_full_name:n {#6} } {#1} {#4}
   }
 \cs_new_protected:Npn \color_profile_apply:nn #1#2
@@ -29912,9 +30068,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \__color_backend_iccbased_device:nnn {#1} { CMYK } { 4 }
   }
 \cs_new_protected:Npn \color_show:n
-  { \__color_show:Nn \msg_show:nnxxxx }
+  { \__color_show:Nn \msg_show:nneeee }
 \cs_new_protected:Npn \color_log:n
-  { \__color_show:Nn \msg_log:nnxxxx }
+  { \__color_show:Nn \msg_log:nneeee }
 \cs_new_protected:Npn \__color_show:Nn #1#2
   {
     #1 { color } { show }
@@ -30123,14 +30279,14 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \__pdf_backend_object_write:nnn {#1} {#2} {#3}
     \bool_gset_true:N \g__pdf_init_bool
   }
-\cs_generate_variant:Nn \pdf_object_write:nnn { nnx }
+\cs_generate_variant:Nn \pdf_object_write:nnn { nne , nnx }
 \cs_new:Npn \pdf_object_ref:n #1 { \__pdf_backend_object_ref:n {#1} }
 \cs_new_protected:Npn \pdf_object_unnamed_write:nn #1#2
   {
     \__pdf_backend_object_now:nn {#1} {#2}
     \bool_gset_true:N \g__pdf_init_bool
   }
-\cs_generate_variant:Nn \pdf_object_unnamed_write:nn { nx }
+\cs_generate_variant:Nn \pdf_object_unnamed_write:nn { ne , nx }
 \cs_new:Npn \pdf_object_ref_last: { \__pdf_backend_object_last: }
 \prg_new_conditional:Npnn \pdf_object_if_exist:n #1 { p , T , F , TF }
   {
@@ -30247,7 +30403,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \pdf_object_write:nn #1#2
   {
-    \exp_args:Nnx \__pdf_backend_object_write:nnn
+    \exp_args:Nne \__pdf_backend_object_write:nnn
       {#1} { \prop_item:Nn \g__pdf_object_prop {#1} } {#2}
     \bool_gset_true:N \g__pdf_init_bool
   }
@@ -30304,7 +30460,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \coffin_if_exist:NTF #1
       { #2 }
       {
-        \msg_error:nnx { coffin } { unknown }
+        \msg_error:nne { coffin } { unknown }
           { \token_to_str:N #1 }
       }
   }
@@ -30389,7 +30545,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
           }
         #5 #1
         \vbox_set_top:Nn \l__coffin_internal_box { \vbox_unpack:N #1 }
-        \__coffin_set_pole:Nnx #1 { T }
+        \__coffin_set_pole:Nne #1 { T }
           {
             { 0pt }
             {
@@ -30402,7 +30558,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \box_clear:N \l__coffin_internal_box
       }
   }
-\cs_new_protected:Npx \__coffin_set_vertical_aux:
+\cs_new_protected:Npe \__coffin_set_vertical_aux:
   {
     \bool_lazy_and:nnT
       { \cs_if_exist_p:N \fmtname }
@@ -30466,7 +30622,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
               #5
               #6 #1
               \vbox_set_top:Nn \l__coffin_internal_box { \vbox_unpack:N #1 }
-              \__coffin_set_pole:Nnx #1 { T }
+              \__coffin_set_pole:Nne #1 { T }
                 {
                   { 0pt }
                   {
@@ -30524,7 +30680,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \prop_get:cnNF
       { coffin ~ \__coffin_to_value:N #1 ~ poles } {#2} #3
       {
-        \msg_error:nnxx { coffin } { unknown-pole }
+        \msg_error:nnee { coffin } { unknown-pole }
           { \exp_not:n {#2} } { \token_to_str:N #1 }
         \tl_set:Nn #3 { { 0pt } { 0pt } { 0pt } { 0pt } }
       }
@@ -30544,10 +30700,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \c__coffin_poles_prop
   }
 \cs_new_protected:Npn \coffin_set_horizontal_pole:Nnn #1#2#3
-  { \__coffin_set_horizontal_pole:NnnN #1 {#2} {#3} \prop_put:cnx }
+  { \__coffin_set_horizontal_pole:NnnN #1 {#2} {#3} \prop_put:cne }
 \cs_generate_variant:Nn \coffin_set_horizontal_pole:Nnn { c }
 \cs_new_protected:Npn \coffin_gset_horizontal_pole:Nnn #1#2#3
-  { \__coffin_set_horizontal_pole:NnnN #1 {#2} {#3} \prop_gput:cnx }
+  { \__coffin_set_horizontal_pole:NnnN #1 {#2} {#3} \prop_gput:cne }
 \cs_generate_variant:Nn \coffin_gset_horizontal_pole:Nnn { c }
 \cs_new_protected:Npn \__coffin_set_horizontal_pole:NnnN #1#2#3#4
   {
@@ -30562,10 +30718,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
   }
 \cs_new_protected:Npn \coffin_set_vertical_pole:Nnn #1#2#3
-  { \__coffin_set_vertical_pole:NnnN #1 {#2} {#3} \prop_put:cnx }
+  { \__coffin_set_vertical_pole:NnnN #1 {#2} {#3} \prop_put:cne }
 \cs_generate_variant:Nn \coffin_set_vertical_pole:Nnn { c }
 \cs_new_protected:Npn \coffin_gset_vertical_pole:Nnn #1#2#3
-  { \__coffin_set_vertical_pole:NnnN #1 {#2} {#3} \prop_gput:cnx }
+  { \__coffin_set_vertical_pole:NnnN #1 {#2} {#3} \prop_gput:cne }
   \cs_generate_variant:Nn \coffin_gset_vertical_pole:Nnn { c }
 \cs_new_protected:Npn \__coffin_set_vertical_pole:NnnN #1#2#3#4
   {
@@ -30584,7 +30740,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \prop_put:cnn { coffin ~ \__coffin_to_value:N #1 ~ poles }
       {#2} {#3}
   }
-\cs_generate_variant:Nn \__coffin_set_pole:Nnn { Nnx }
+\cs_generate_variant:Nn \__coffin_set_pole:Nnn { Nne }
 \cs_new_protected:Npn \coffin_reset_poles:N #1
   {
     \__coffin_reset_structure:N #1
@@ -30598,9 +30754,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \__coffin_gupdate_poles:N #1
   }
 \cs_new_protected:Npn \__coffin_update_corners:N #1
-  { \__coffin_update_corners:NN #1 \prop_put:Nnx }
+  { \__coffin_update_corners:NN #1 \prop_put:Nne }
 \cs_new_protected:Npn \__coffin_gupdate_corners:N #1
-  { \__coffin_update_corners:NN #1 \prop_gput:Nnx }
+  { \__coffin_update_corners:NN #1 \prop_gput:Nne }
 \cs_new_protected:Npn \__coffin_update_corners:NN #1#2
   {
     \exp_args:Nc \__coffin_update_corners:NNN
@@ -30629,9 +30785,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
   }
 \cs_new_protected:Npn \__coffin_update_poles:N #1
-  { \__coffin_update_poles:NN #1 \prop_put:Nnx }
+  { \__coffin_update_poles:NN #1 \prop_put:Nne }
 \cs_new_protected:Npn \__coffin_gupdate_poles:N #1
-  { \__coffin_update_poles:NN #1 \prop_gput:Nnx }
+  { \__coffin_update_poles:NN #1 \prop_gput:Nne }
 \cs_new_protected:Npn \__coffin_update_poles:NN #1#2
   {
     \exp_args:Nc \__coffin_update_poles:NNN
@@ -30734,7 +30890,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
               }
           }
           {
-            \use:x
+            \use:e
               {
                 \__coffin_calculate_intersection:nnnnnn
                   { \dim_to_fp:n {#4} / \dim_to_fp:n {#3} }
@@ -30831,17 +30987,17 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__coffin_set_bounding:N #1
   {
-    \prop_put:Nnx \l__coffin_bounding_prop { tl }
+    \prop_put:Nne \l__coffin_bounding_prop { tl }
       { { 0pt } { \dim_eval:n { \box_ht:N #1 } } }
-    \prop_put:Nnx \l__coffin_bounding_prop { tr }
+    \prop_put:Nne \l__coffin_bounding_prop { tr }
       {
         { \dim_eval:n { \box_wd:N #1 } }
         { \dim_eval:n { \box_ht:N #1 } }
       }
     \dim_set:Nn \l__coffin_internal_dim { -\box_dp:N #1 }
-    \prop_put:Nnx \l__coffin_bounding_prop { bl }
+    \prop_put:Nne \l__coffin_bounding_prop { bl }
       { { 0pt } { \dim_use:N \l__coffin_internal_dim } }
-    \prop_put:Nnx \l__coffin_bounding_prop { br }
+    \prop_put:Nne \l__coffin_bounding_prop { br }
       {
         { \dim_eval:n { \box_wd:N #1 } }
         { \dim_use:N \l__coffin_internal_dim }
@@ -30850,13 +31006,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__coffin_rotate_bounding:nnn #1#2#3
   {
     \__coffin_rotate_vector:nnNN {#2} {#3} \l__coffin_x_dim \l__coffin_y_dim
-    \prop_put:Nnx \l__coffin_bounding_prop {#1}
+    \prop_put:Nne \l__coffin_bounding_prop {#1}
       { { \dim_use:N \l__coffin_x_dim } { \dim_use:N \l__coffin_y_dim } }
   }
 \cs_new_protected:Npn \__coffin_rotate_corner:Nnnn #1#2#3#4
   {
     \__coffin_rotate_vector:nnNN {#3} {#4} \l__coffin_x_dim \l__coffin_y_dim
-    \prop_put:Nnx \l__coffin_corners_prop {#2}
+    \prop_put:Nne \l__coffin_corners_prop {#2}
       { { \dim_use:N \l__coffin_x_dim } { \dim_use:N \l__coffin_y_dim } }
   }
 \cs_new_protected:Npn \__coffin_rotate_pole:Nnnnnn #1#2#3#4#5#6
@@ -30864,7 +31020,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \__coffin_rotate_vector:nnNN {#3} {#4} \l__coffin_x_dim \l__coffin_y_dim
     \__coffin_rotate_vector:nnNN {#5} {#6}
       \l__coffin_x_prime_dim \l__coffin_y_prime_dim
-    \prop_put:Nnx \l__coffin_poles_prop {#2}
+    \prop_put:Nne \l__coffin_poles_prop {#2}
       {
         { \dim_use:N \l__coffin_x_dim } { \dim_use:N \l__coffin_y_dim }
         { \dim_use:N \l__coffin_x_prime_dim }
@@ -30923,7 +31079,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__coffin_shift_corner:Nnnn #1#2#3#4
   {
-    \prop_put:Nnx \l__coffin_corners_prop {#2}
+    \prop_put:Nne \l__coffin_corners_prop {#2}
       {
         { \dim_eval:n { #3 - \l__coffin_left_corner_dim } }
         { \dim_eval:n { #4 - \l__coffin_bottom_corner_dim } }
@@ -30931,7 +31087,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__coffin_shift_pole:Nnnnnn #1#2#3#4#5#6
   {
-    \prop_put:Nnx \l__coffin_poles_prop {#2}
+    \prop_put:Nne \l__coffin_poles_prop {#2}
       {
         { \dim_eval:n { #3 - \l__coffin_left_corner_dim } }
         { \dim_eval:n { #4 - \l__coffin_bottom_corner_dim } }
@@ -31021,13 +31177,13 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__coffin_scale_corner:Nnnn #1#2#3#4
   {
     \__coffin_scale_vector:nnNN {#3} {#4} \l__coffin_x_dim \l__coffin_y_dim
-    \prop_put:Nnx \l__coffin_corners_prop {#2}
+    \prop_put:Nne \l__coffin_corners_prop {#2}
       { { \dim_use:N \l__coffin_x_dim } { \dim_use:N \l__coffin_y_dim } }
   }
 \cs_new_protected:Npn \__coffin_scale_pole:Nnnnnn #1#2#3#4#5#6
   {
     \__coffin_scale_vector:nnNN {#3} {#4} \l__coffin_x_dim \l__coffin_y_dim
-    \prop_put:Nnx \l__coffin_poles_prop {#2}
+    \prop_put:Nne \l__coffin_poles_prop {#2}
       {
         { \dim_use:N \l__coffin_x_dim } { \dim_use:N \l__coffin_y_dim }
         {#5} {#6}
@@ -31035,14 +31191,14 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__coffin_x_shift_corner:Nnnn #1#2#3#4
   {
-    \prop_put:Nnx \l__coffin_corners_prop {#2}
+    \prop_put:Nne \l__coffin_corners_prop {#2}
       {
         { \dim_eval:n { #3 + \box_wd:N #1 } } {#4}
       }
   }
 \cs_new_protected:Npn \__coffin_x_shift_pole:Nnnnnn #1#2#3#4#5#6
   {
-    \prop_put:Nnx \l__coffin_poles_prop {#2}
+    \prop_put:Nne \l__coffin_poles_prop {#2}
       {
         { \dim_eval:n { #3 + \box_wd:N #1 } } {#4}
         {#5} {#6}
@@ -31172,7 +31328,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \tl_if_in:nnTF {#2} { - }
       { \tl_set:Nn \l__coffin_internal_tl { {#2} } }
       { \tl_set:Nn \l__coffin_internal_tl { { #1 - #2 } } }
-    \exp_last_unbraced:NNo \__coffin_set_pole:Nnx \l__coffin_aligned_coffin
+    \exp_last_unbraced:NNo \__coffin_set_pole:Nne \l__coffin_aligned_coffin
       { \l__coffin_internal_tl }
       {
         { \dim_use:N \l__coffin_x_dim } { \dim_use:N \l__coffin_y_dim }
@@ -31186,7 +31342,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__coffin_offset_corner:Nnnnn #1#2#3#4#5#6
   {
-    \prop_put:cnx
+    \prop_put:cne
       {
         coffin ~ \__coffin_to_value:N \l__coffin_aligned_coffin
         \c_space_tl corners
@@ -31212,11 +31368,11 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \dim_compare:nNnTF {#2} < {#6}
       {
-        \__coffin_set_pole:Nnx #9 { T }
+        \__coffin_set_pole:Nne #9 { T }
           { { 0pt } {#6} { 1000pt } { 0pt } }
       }
       {
-        \__coffin_set_pole:Nnx #9 { T }
+        \__coffin_set_pole:Nne #9 { T }
           { { 0pt } {#2} { 1000pt } { 0pt } }
       }
   }
@@ -31224,11 +31380,11 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   {
     \dim_compare:nNnTF {#2} < {#6}
       {
-        \__coffin_set_pole:Nnx #9 { B }
+        \__coffin_set_pole:Nne #9 { B }
           { { 0pt } {#2}  { 1000pt } { 0pt } }
       }
       {
-        \__coffin_set_pole:Nnx #9 { B }
+        \__coffin_set_pole:Nne #9 { B }
           { { 0pt } {#6} { 1000pt } { 0pt } }
       }
   }
@@ -31446,10 +31602,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \box_set_eq:NN \l__coffin_display_coffin \l__coffin_aligned_coffin
   }
 \cs_new_protected:Npn \coffin_show_structure:N
-  { \__coffin_show_structure:NN \msg_show:nnxxxx }
+  { \__coffin_show_structure:NN \msg_show:nneeee }
 \cs_generate_variant:Nn \coffin_show_structure:N { c }
 \cs_new_protected:Npn \coffin_log_structure:N
-  { \__coffin_show_structure:NN \msg_log:nnxxxx }
+  { \__coffin_show_structure:NN \msg_log:nneeee }
 \cs_generate_variant:Nn \coffin_log_structure:N { c }
 \cs_new_protected:Npn \__coffin_show_structure:NN #1#2
   {
@@ -31477,10 +31633,10 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \coffin_log:Nnn #1 \c_max_int \c_max_int }
 \cs_generate_variant:Nn \coffin_log:N { c }
 \cs_new_protected:Npn \coffin_show:Nnn
-  { \__coffin_show:NNNnn \msg_term:nnxxxx \box_show:Nnn }
+  { \__coffin_show:NNNnn \msg_term:nneeee \box_show:Nnn }
 \cs_generate_variant:Nn \coffin_show:Nnn { c }
 \cs_new_protected:Npn \coffin_log:Nnn
-  { \__coffin_show:NNNnn \msg_log:nnxxxx \box_show:Nnn }
+  { \__coffin_show:NNNnn \msg_log:nneeee \box_show:Nnn }
 \cs_generate_variant:Nn \coffin_log:Nnn { c }
 \cs_new_protected:Npn \__coffin_show:NNNnn #1#2#3#4#5
   {
@@ -31828,7 +31984,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     }
   \cs_set_protected:Npn \__codepoint_data_auxii:w #1 ; #2 ~ #3 \q_stop
     {
-      \tl_const:cx
+      \tl_const:ce
         { c__codepoint_nfd_ \codepoint_str_generate:n {"#1} _tl }
         {
           {"#2}
@@ -31868,11 +32024,11 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       \__codepoint_add:nn { lowercase } {#5}
       \int_compare:nNnF {#4} = { \__codepoint_data_offset:nn {#1} {#6} }
         {
-          \tl_const:cx
+          \tl_const:ce
             { c__codepoint_titlecase_ \codepoint_str_generate:n {"#1} _tl }
             { {"#6} { } { } }
         }
-      \tl_set:Nx \l__codepoint_next_codepoint_fint_tl
+      \tl_set:Ne \l__codepoint_next_codepoint_fint_tl
         { \int_eval:n { "#1 + 1 } }
     }
   \cs_set_protected:Npn \__codepoint_add:nn #1#2
@@ -31882,7 +32038,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         = \c__codepoint_block_size_int
         { \__codepoint_save_blocks:nn {#1} { 1 } }
     }
-  \cs_set_protected:Npx \__codepoint_data_auxv:nnnnw #1#2#3#4#5 Last> #6 \q_stop
+  \cs_set_protected:Npe \__codepoint_data_auxv:nnnnw #1#2#3#4#5 Last> #6 \q_stop
     {
        \exp_not:N \tl_if_blank:nTF {#6}
          {
@@ -31925,7 +32081,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
      \int_compare:nNnF
        { \int_div_truncate:nn { #2 - #1 } \c__codepoint_block_size_int } = 0
        {
-         \tl_set:cx { l__codepoint_ #3 _block_clist }
+         \tl_set:ce { l__codepoint_ #3 _block_clist }
            {
              \exp_args:NNe \use:nn \use_none:n
                { \prg_replicate:nn { \c__codepoint_block_size_int } { , #4 } }
@@ -31935,7 +32091,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         }
      \prg_replicate:nn
        { \int_mod:nn { #2 - #1 } \c__codepoint_block_size_int }
-       { \clist_put_right:cx { l__codepoint_ #3 _block_clist } {#4} }
+       { \clist_put_right:ce { l__codepoint_ #3 _block_clist } {#4} }
     }
   \cs_set_protected:Npn \__codepoint_save_blocks:nn #1#2
     {
@@ -31955,12 +32111,12 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
                 \tl_use:c { l__codepoint_ #1 _block_tl } _clist
               }
               { l__codepoint_ #1 _block_clist }
-            \tl_set:cx { l__codepoint_ #1 _block_tl }
+            \tl_set:ce { l__codepoint_ #1 _block_tl }
               { \int_eval:n { \tl_use:c { l__codepoint_ #1 _block_tl } + 1 } }
           }
         \prg_replicate:nn {#2}
           {
-            \tl_set:cx { l__codepoint_ #1 _pos_tl }
+            \tl_set:ce { l__codepoint_ #1 _pos_tl }
               { \int_eval:n { \tl_use:c { l__codepoint_ #1 _pos_tl } + 1 } }
             \exp_args:Nc \__kernel_intarray_gset:Nnn
               { g__codepoint_ #1 _index_intarray }
@@ -32055,7 +32211,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \reverse_if:N \if_int_compare:w
           \int_eval:n { \__kernel_codepoint_data:nn { lowercase } {"#1} + "#1 }
             = "#3 ~
-          \tl_const:cx
+          \tl_const:ce
             { c__codepoint_casefold_ \codepoint_str_generate:n {"#1} _tl }
             { {"#3} { } { } }
         \fi:
@@ -32067,7 +32223,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     }
   \cs_set_protected:Npn \__codepoint_data_auxii:w #1 ~ #2 ~ #3 ~ #4 \q_stop
     {
-      \tl_const:cx { c__codepoint_casefold_ \codepoint_str_generate:n {"#1} _tl }
+      \tl_const:ce { c__codepoint_casefold_ \codepoint_str_generate:n {"#1} _tl }
         {
           {"#2}
           {"#3}
@@ -32095,7 +32251,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     {
       \tl_if_empty:nF {#4}
         {
-          \tl_const:cx { c__codepoint_ #2 case_ \codepoint_str_generate:n {"#1} _tl }
+          \tl_const:ce { c__codepoint_ #2 case_ \codepoint_str_generate:n {"#1} _tl }
             {
               {"#3}
               {"#4}
@@ -32159,7 +32315,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         {
           \str_if_empty:NF \l__text_tmpb_str
             {
-              \clist_const:cx { c__text_grapheme_ \l__text_tmpb_str _clist }
+              \clist_const:ce { c__text_grapheme_ \l__text_tmpb_str _clist }
                 { \exp_after:wN \use_none:n \l__text_tmpa_str }
               \cs_set_nopar:Npn \l__text_tmpa_str { }
             }
@@ -32169,7 +32325,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     }
   \cs_set_protected:Npn \__text_data_auxii:w #1 .. #2 .. #3 \q_stop
     {
-      \cs_set_nopar:Npx \l__text_tmpa_str
+      \cs_set_nopar:Npe \l__text_tmpa_str
         {
           \l__text_tmpa_str ,
           \tl_trim_spaces:n {#1} .. \tl_trim_spaces:n {#2}
@@ -32353,7 +32509,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \cs_new:Npn \__text_codepoint_process:nN #1#2 { #1 {#2} }
   }
   {
-    \cs_new:Npx \__text_codepoint_process:nN #1#2
+    \cs_new:Npe \__text_codepoint_process:nN #1#2
       {
         \exp_not:N \int_compare:nNnTF {`#2} > { "80 }
           {
@@ -32406,7 +32562,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
             #2 {#3}
           \prg_return_true: \prg_return_false:
       }
-    \cs_new:Npx \__text_codepoint_from_chars:Nw #1
+    \cs_new:Npe \__text_codepoint_from_chars:Nw #1
       {
         \exp_not:N \if_int_compare:w `#1 > "80 \exp_not:N \exp_stop_f:
           \sys_if_engine_pdftex:TF
@@ -32461,7 +32617,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \tl_new:N \l_text_accents_tl
 \tl_new:N \l_text_letterlike_tl
 \tl_new:N \l_text_case_exclude_arg_tl
-\tl_set:Nx \l_text_case_exclude_arg_tl
+\tl_set:Ne \l_text_case_exclude_arg_tl
   {
     \exp_not:n { \begin \cite \end \label \ref }
     \exp_not:c { cite ~ }
@@ -32730,7 +32886,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
       { \__text_expand_letterlike:NN #1 }
   }
-\cs_new:Npx \__text_expand_cs:N #1
+\cs_new:Npe \__text_expand_cs:N #1
   {
     \exp_not:N \str_if_eq:nnTF {#1} { \exp_not:N \protect }
       { \exp_not:N \__text_expand_protect:w }
@@ -32906,15 +33062,15 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new:Npn \__text_change_case_auxi:nnn #1#2#3
   { \exp_args:No \__text_change_case_BCP:nnn { \tl_to_str:n {#3} } {#1} {#2} }
-\cs_new:Npx \__text_change_case_BCP:nnn #1#2#3
+\cs_new:Npe \__text_change_case_BCP:nnn #1#2#3
   {
     \exp_not:N \__text_change_case_BCP:nnw
       {#2} {#3} #1 \tl_to_str:n { -x- -x- } \exp_not:N \q__text_stop
   }
-\use:x
+\use:e
   {
     \cs_new:Npn \exp_not:N \__text_change_case_BCP:nnw
-      ##1##2##3 \tl_to_str:n { -x- } ##4 \tl_to_str:n { -x- } ##5
+      #1#2#3 \tl_to_str:n { -x- } #4 \tl_to_str:n { -x- } #5
       \exp_not:N \q__text_stop
   }
   { \__text_change_case_BCP:nnnnw {#1} {#2} {#4} {#3} #3 - - \q__text_stop }
@@ -33001,9 +33157,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
     \__text_change_case_break:w
   }
-\use:x
+\use:e
   {
-    \cs_new:Npn \exp_not:N \__text_change_case_space:nnw ##1##2 \c_space_tl
+    \cs_new:Npn \exp_not:N \__text_change_case_space:nnw #1#2 \c_space_tl
   }
   {
     \__text_change_case_store:n { ~ }
@@ -33066,9 +33222,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \__text_change_case_store:n { {#4} }
     \__text_change_case_math_loop:nnNw {#1} {#2} #3
   }
-\use:x
+\use:e
   {
-    \cs_new:Npn \exp_not:N \__text_change_case_math_space:nnNw ##1##2##3
+    \cs_new:Npn \exp_not:N \__text_change_case_math_space:nnNw #1#2#3
       \c_space_tl
   }
   {
@@ -34518,8 +34674,8 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     }
     \__text_map_loop:Nnw #1 { }
   }
-\use:x
-  { \cs_new:Npn \exp_not:N \__text_map_space:Nnw ##1##2 \c_space_tl }
+\use:e
+  { \cs_new:Npn \exp_not:N \__text_map_space:Nnw #1#2 \c_space_tl }
   {
     \__text_map_output:Nn #1 {#2}
     #1 { ~ }
@@ -35037,7 +35193,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \tl_clear_new:c { l__text_purify_ \token_to_str:N #1 _tl }
     \tl_set:cn { l__text_purify_ \token_to_str:N #1 _tl } {#2}
   }
-\cs_generate_variant:Nn \text_declare_purify_equivalent:Nn { Nx }
+\cs_generate_variant:Nn \text_declare_purify_equivalent:Nn { Ne }
 \tl_map_inline:nn
   {
     \fontencoding
@@ -35099,14 +35255,14 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \text_declare_purify_equivalent:Nn \\ { }
 \tl_map_inline:nn
   { \{ \} \# \$ \% \_ }
-  { \text_declare_purify_equivalent:Nx #1 { \cs_to_str:N #1 } }
+  { \text_declare_purify_equivalent:Ne #1 { \cs_to_str:N #1 } }
 \text_declare_purify_equivalent:Nn \label { \use_none:n }
 \group_begin:
 \char_set_catcode_active:N \~
 \use:n
   {
     \group_end:
-    \text_declare_purify_equivalent:Nx ~ { \c_space_tl }
+    \text_declare_purify_equivalent:Ne ~ { \c_space_tl }
   }
 \text_declare_purify_equivalent:Nn \nobreakspace { ~ }
 \text_declare_purify_equivalent:Nn \  { ~ }
@@ -35114,7 +35270,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_set_protected:Npn \__text_loop:Nn #1#2
   {
     \quark_if_recursion_tail_stop:N #1
-    \text_declare_purify_equivalent:Nx #1
+    \text_declare_purify_equivalent:Ne #1
       {
         \codepoint_generate:nn {"#2}
           { \char_value_catcode:n {"#2} }
@@ -35167,7 +35323,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   \cs_set_protected:Npn \__text_loop:Nn #1#2
     {
       \quark_if_recursion_tail_stop:N #1
-      \tl_const:cx { c__text_purify_ \token_to_str:N #1 _tl }
+      \tl_const:ce { c__text_purify_ \token_to_str:N #1 _tl }
         { \codepoint_generate:nn {"#2} { \char_value_catcode:n { "#2 } } }
       \__text_loop:Nn
     }
@@ -35193,7 +35349,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   \cs_set_protected:Npn \__text_loop:NNn #1#2#3
     {
       \quark_if_recursion_tail_stop:N #1
-      \tl_const:cx
+      \tl_const:ce
         { c__text_purify_ \token_to_str:N #1 _ \token_to_str:N #2 _tl }
         { \codepoint_generate:nn {"#3} { \char_value_catcode:n { "#3 } } }
       \__text_loop:NNn
@@ -35411,9 +35567,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \group_end:
 %% File: l3candidates.dtx
 \cs_new_protected:Npn \seq_set_filter:NNn
-  { \__seq_set_filter:NNNn \__kernel_tl_set:Nx }
+  { \__seq_set_filter:NNNn \__kernel_tl_set:Ne }
 \cs_new_protected:Npn \seq_gset_filter:NNn
-  { \__seq_set_filter:NNNn \__kernel_tl_gset:Nx }
+  { \__seq_set_filter:NNNn \__kernel_tl_gset:Ne }
 \cs_new_protected:Npn \__seq_set_filter:NNNn #1#2#3#4
   {
     \__seq_push_item_def:n { \bool_if:nT {#4} { \__seq_wrap_item:n {##1} } }
@@ -35421,9 +35577,9 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     \__seq_pop_item_def:
   }
 \cs_new_protected:Npn \tl_build_begin:N #1
-  { \__tl_build_begin:NN \cs_set_nopar:Npx #1 }
+  { \__tl_build_begin:NN \cs_set_nopar:Npe #1 }
 \cs_new_protected:Npn \tl_build_gbegin:N #1
-  { \__tl_build_begin:NN \cs_gset_nopar:Npx #1 }
+  { \__tl_build_begin:NN \cs_gset_nopar:Npe #1 }
 \cs_new_protected:Npn \__tl_build_begin:NN #1#2
   { \exp_args:Nc \__tl_build_begin:NNN { \cs_to_str:N #2 ' } #2 #1 }
 \cs_new_protected:Npn \__tl_build_begin:NNN #1#2#3
@@ -35439,24 +35595,16 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_eq:NN \tl_build_gclear:N \tl_build_gbegin:N
 \cs_new_protected:Npn \tl_build_put_right:Nn #1#2
   {
-    \cs_set_nopar:Npx #1
+    \cs_set_nopar:Npe #1
       { \exp_after:wN \exp_not:n \exp_after:wN { \exp:w #1 #2 } }
   }
-\cs_new_protected:Npn \tl_build_put_right:Nx #1#2
-  {
-    \cs_set_nopar:Npx #1
-      { \exp_after:wN \exp_not:n \exp_after:wN { \exp:w #1 } #2 }
-  }
+\cs_generate_variant:Nn \tl_build_put_right:Nn { Ne , Nx }
 \cs_new_protected:Npn \tl_build_gput_right:Nn #1#2
   {
-    \cs_gset_nopar:Npx #1
+    \cs_gset_nopar:Npe #1
       { \exp_after:wN \exp_not:n \exp_after:wN { \exp:w #1 #2 } }
   }
-\cs_new_protected:Npn \tl_build_gput_right:Nx #1#2
-  {
-    \cs_gset_nopar:Npx #1
-      { \exp_after:wN \exp_not:n \exp_after:wN { \exp:w #1 } #2 }
-  }
+\cs_generate_variant:Nn \tl_build_gput_right:Nn { Ne , Nx }
 \cs_new_protected:Npn \__tl_build_last:NNn #1#2
   {
     \if_false: { { \fi:
@@ -35478,11 +35626,11 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
 \cs_new_protected:Npn \__tl_build_put:nw #1#2 \__tl_build_last:NNn #3#4#5
   { #2 \__tl_build_last:NNn #3 #4 { #1 #5 } }
 \cs_new_protected:Npn \tl_build_put_left:Nn #1
-  { \__tl_build_put_left:NNn \cs_set_nopar:Npx #1 }
-\cs_generate_variant:Nn \tl_build_put_left:Nn { Nx }
+  { \__tl_build_put_left:NNn \cs_set_nopar:Npe #1 }
+\cs_generate_variant:Nn \tl_build_put_left:Nn { Ne , Nx }
 \cs_new_protected:Npn \tl_build_gput_left:Nn #1
-  { \__tl_build_put_left:NNn \cs_gset_nopar:Npx #1 }
-\cs_generate_variant:Nn \tl_build_gput_left:Nn { Nx }
+  { \__tl_build_put_left:NNn \cs_gset_nopar:Npe #1 }
+\cs_generate_variant:Nn \tl_build_gput_left:Nn { Ne , Nx }
 \cs_new_protected:Npn \__tl_build_put_left:NNn #1#2#3
   {
     #1 #2
@@ -35495,7 +35643,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
       }
   }
 \cs_new_protected:Npn \tl_build_get:NN
-  { \__tl_build_get:NNN \__kernel_tl_set:Nx }
+  { \__tl_build_get:NNN \__kernel_tl_set:Ne }
 \cs_new_protected:Npn \__tl_build_get:NNN #1#2#3
   { #1 #3 { \if_false: { \fi: \exp_after:wN \__tl_build_get:w #2 } } }
 \cs_new:Npn \__tl_build_get:w #1 \__tl_build_last:NNn #2#3#4
@@ -35510,12 +35658,12 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   { \exp_after:wN \exp_not:n \exp_after:wN { \if_false: } \fi: }
 \cs_new_protected:Npn \tl_build_end:N #1
   {
-    \__tl_build_get:NNN \__kernel_tl_set:Nx #1 #1
+    \__tl_build_get:NNN \__kernel_tl_set:Ne #1 #1
     \exp_args:Nc \__tl_build_end_loop:NN { \cs_to_str:N #1 ' } \tl_clear:N
   }
 \cs_new_protected:Npn \tl_build_gend:N #1
   {
-    \__tl_build_get:NNN \__kernel_tl_gset:Nx #1 #1
+    \__tl_build_get:NNN \__kernel_tl_gset:Ne #1 #1
     \exp_args:Nc \__tl_build_end_loop:NN { \cs_to_str:N #1 ' } \tl_gclear:N
   }
 \cs_new_protected:Npn \__tl_build_end_loop:NN #1#2
@@ -35571,11 +35719,11 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
   }
 \cs_new_protected:Npn \__deprecation_warn_once:nnNnn #1#2#3#4#5
   {
-    \cs_gset_protected:Npx #3
+    \cs_gset_protected:Npe #3
       {
         \__kernel_if_debug:TF
           {
-            \exp_not:N \msg_warning:nnxxx
+            \exp_not:N \msg_warning:nneee
               { deprecation } { deprecated-command }
               {#1}
               { \token_to_str:N #3 }
@@ -35602,7 +35750,7 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
         \exp_not:N \msg_expandable_error:nnnnn
           { deprecation } { deprecated-command }
           { \tl_to_str:n {#3} } { \token_to_str:N #1 } { \tl_to_str:n {#2} }
-        \exp_not:N \msg_error:nnxxx
+        \exp_not:N \msg_error:nneee
           { deprecation } { deprecated-command }
           { \tl_to_str:n {#3} } { \token_to_str:N #1 } { \tl_to_str:n {#2} }
       }
@@ -35932,25 +36080,25 @@ Type  H <return>  for immediate help}\def~{\errmessage{%
     { meaning } { meaning_remove }
   }
   {
-    \use:x
+    \use:e
       {
         \__kernel_patch_deprecation:nnNNpn { 2022-01-11 } { \peek_remove_spaces:n }
-        \cs_gset_protected:Npn \exp_not:c { peek_ #1 _ignore_spaces:NTF } ####1####2####3
+        \cs_gset_protected:Npn \exp_not:c { peek_ #1 _ignore_spaces:NTF } ##1##2##3
           {
             \peek_remove_spaces:n
-              { \exp_not:c { peek_ #1 :NTF } ####1 {####2} {####3} }
+              { \exp_not:c { peek_ #1 :NTF } ##1 {##2} {##3} }
           }
         \__kernel_patch_deprecation:nnNNpn { 2022-01-11 } { \peek_remove_spaces:n }
-        \cs_gset_protected:Npn \exp_not:c { peek_ #1 _ignore_spaces:NT } ####1####2
+        \cs_gset_protected:Npn \exp_not:c { peek_ #1 _ignore_spaces:NT } ##1##2
           {
             \peek_remove_spaces:n
-              { \exp_not:c { peek_ #1 :NT } ####1 {####2} }
+              { \exp_not:c { peek_ #1 :NT } ##1 {##2} }
           }
         \__kernel_patch_deprecation:nnNNpn { 2022-01-11 } { \peek_remove_spaces:n }
-        \cs_gset_protected:Npn \exp_not:c { peek_ #1 _ignore_spaces:NF } ####1####2
+        \cs_gset_protected:Npn \exp_not:c { peek_ #1 _ignore_spaces:NF } ##1##2
           {
             \peek_remove_spaces:n
-              { \exp_not:c { peek_ #1 :NF } ####1 {####2} }
+              { \exp_not:c { peek_ #1 :NF } ##1 {##2} }
           }
       }
   }
diff --git a/Master/texmf-dist/tex/latex/l3kernel/expl3-generic.tex b/Master/texmf-dist/tex/latex/l3kernel/expl3-generic.tex
index 45d89a2b1da..84a815a5fe0 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/expl3-generic.tex
+++ b/Master/texmf-dist/tex/latex/l3kernel/expl3-generic.tex
@@ -19,7 +19,7 @@
 %% and all files in that bundle must be distributed together.
 %% 
 %% File: expl3.dtx
-\def\ExplFileDate{2023-08-29}%
+\def\ExplFileDate{2023-10-10}%
 \let\ExplLoaderFileDate\ExplFileDate
 \begingroup
   \catcode`\_=11
@@ -88,7 +88,7 @@
     \cs_set_protected:Npn \ProvidesExplFileAux ##1##2##3##4
       {
         \group_end:
-        \iow_log:x { File:~##1~##2~v##3~##4 }
+        \iow_log:e { File:~##1~##2~v##3~##4 }
       }
     \tex_input:D #1 .def \scan_stop:
   }
diff --git a/Master/texmf-dist/tex/latex/l3kernel/expl3.ltx b/Master/texmf-dist/tex/latex/l3kernel/expl3.ltx
index 2cbd97f253c..fc9349d64ff 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/expl3.ltx
+++ b/Master/texmf-dist/tex/latex/l3kernel/expl3.ltx
@@ -19,7 +19,7 @@
 %% and all files in that bundle must be distributed together.
 %% 
 %% File: expl3.dtx
-\def\ExplFileDate{2023-08-29}%
+\def\ExplFileDate{2023-10-10}%
 \let\ExplLoaderFileDate\ExplFileDate
 \begingroup
   \catcode`\_=11
@@ -151,12 +151,12 @@
   }
 \cs_gset_protected:Npn \@expl@push@filename@@
   {
-    \exp_args:Nx \__kernel_file_input_push:n
+    \exp_args:Ne \__kernel_file_input_push:n
       {
         \tl_to_str:N \@currname .
         \tl_to_str:N \@currext
       }
-    \tl_put_left:Nx \l__expl_status_stack_tl
+    \tl_put_left:Ne \l__expl_status_stack_tl
       {
         \bool_if:NTF \l__kernel_expl_bool
           { 1 }
diff --git a/Master/texmf-dist/tex/latex/l3kernel/expl3.sty b/Master/texmf-dist/tex/latex/l3kernel/expl3.sty
index ddd58a9acb0..2e3d4947d8b 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/expl3.sty
+++ b/Master/texmf-dist/tex/latex/l3kernel/expl3.sty
@@ -19,7 +19,7 @@
 %% and all files in that bundle must be distributed together.
 %% 
 %% File: expl3.dtx
-\def\ExplFileDate{2023-08-29}%
+\def\ExplFileDate{2023-10-10}%
 \let\ExplLoaderFileDate\ExplFileDate
 \ProvidesPackage{expl3}
   [%
@@ -178,12 +178,12 @@
   }
 \cs_gset_protected:Npn \@expl@push@filename@@
   {
-    \exp_args:Nx \__kernel_file_input_push:n
+    \exp_args:Ne \__kernel_file_input_push:n
       {
         \tl_to_str:N \@currname .
         \tl_to_str:N \@currext
       }
-    \tl_put_left:Nx \l__expl_status_stack_tl
+    \tl_put_left:Ne \l__expl_status_stack_tl
       {
         \bool_if:NTF \l__kernel_expl_bool
           { 1 }
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3debug.def b/Master/texmf-dist/tex/latex/l3kernel/l3debug.def
index af741efb155..5a506c6cb41 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3debug.def
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3debug.def
@@ -71,7 +71,7 @@
   }
 \cs_set_protected:Npn \debug_resume:
   {
-    \__kernel_tl_set:Nx \l__debug_suspended_tl
+    \__kernel_tl_set:Ne \l__debug_suspended_tl
       { \tl_tail:N \l__debug_suspended_tl }
     \tl_if_empty:NT \l__debug_suspended_tl
       {
@@ -93,7 +93,7 @@
         \__debug_suspended:T \use_none:nnn
         \cs_if_exist:NF ##1
           {
-            \msg_error:nnx { debug } { non-declared-variable }
+            \msg_error:nne { debug } { non-declared-variable }
               { \token_to_str:N ##1 }
           }
       }
@@ -102,7 +102,7 @@
         \__debug_suspended:T \use_none:nnn
         \cs_if_exist:NF ##1
           {
-            \msg_error:nnx { kernel } { command-not-defined }
+            \msg_error:nne { kernel } { command-not-defined }
               { \token_to_str:N ##1 }
           }
       }
@@ -163,7 +163,7 @@
       \if:w #1 \scan_stop:
         \cs_gset_nopar:Npn #1 {#2}
       \else:
-        \msg_error:nnxxx { debug } { local-global }
+        \msg_error:nneee { debug } { local-global }
           {#1} {#2} { \iow_char:N \\ #3 }
       \fi:
     \fi:
@@ -171,12 +171,12 @@
 \use:c { __debug_check-declarations_off: }
 \cs_new_protected:cpn { __debug_log-functions_on: }
   {
-    \cs_set_protected:Npn \__kernel_debug_log:x
-      { \__debug_suspended:T \use_none:nn \iow_log:x }
+    \cs_set_protected:Npn \__kernel_debug_log:e
+      { \__debug_suspended:T \use_none:nn \iow_log:e }
   }
 \cs_new_protected:cpn { __debug_log-functions_off: }
-  { \cs_set_protected:Npn \__kernel_debug_log:x { \use_none:n } }
-\cs_new_protected:Npn \__kernel_debug_log:x { \use_none:n }
+  { \cs_set_protected:Npn \__kernel_debug_log:e { \use_none:n } }
+\cs_new_protected:Npn \__kernel_debug_log:e { \use_none:n }
 \cs_new_protected:cpn { __debug_check-expressions_on: }
   {
     \cs_set:Npn \__kernel_chk_expr:nNnN ##1##2
@@ -213,11 +213,11 @@
 \tl_new:N \l__debug_tmpb_tl
 \cs_new_protected:Npn \__debug_generate_parameter_list:NNN #1#2#3
   {
-    \__kernel_tl_set:Nx \l__debug_internal_tl
+    \__kernel_tl_set:Ne \l__debug_internal_tl
       { \exp_last_unbraced:Nf \use_ii:nnn \cs_split_function:N #1 }
-    \__kernel_tl_set:Nx #2
+    \__kernel_tl_set:Ne #2
       { \exp_args:NV \__debug_build_parm_text:n \l__debug_internal_tl }
-    \__kernel_tl_set:Nx #3
+    \__kernel_tl_set:Ne #3
       { \exp_args:NV \__debug_build_arg_list:n \l__debug_internal_tl }
   }
 \cs_new:Npn \__debug_build_parm_text:n #1
@@ -317,7 +317,7 @@
     {
       \cs_gset_eq:cN { __debug_ \cs_to_str:N #1 } #1
       \__debug_generate_parameter_list:NNN #1 \l__debug_tmpa_tl \l__debug_tmpb_tl
-      \exp_args:Nx \tex_scantokens:D
+      \exp_args:Ne \tex_scantokens:D
         {
           \tex_global:D \cs_prefix_spec:N #1
           \tex_def:D \exp_not:N #1
@@ -332,23 +332,23 @@
     }
   \cs_set_protected:Npn \__debug_add_to_debug_code:Nnn #1#2#3
     {
-      \use:x
+      \use:e
         {
           \cs_set:Npn \exp_not:N \__debug_tmp:w
-            ####1 \tl_to_str:n { macro: }
-            ####2 \tl_to_str:n { -> }
-            ####3 \c_backslash_str \tl_to_str:n { __debug_ }
+            ##1 \tl_to_str:n { macro: }
+            ##2 \tl_to_str:n { -> }
+            ##3 \c_backslash_str \tl_to_str:n { __debug_ }
                     \cs_to_str:N #1
-            ####4 \s__debug_stop
+            ##4 \s__debug_stop
             {
-              \exp_not:N \exp_args:Nx \exp_not:N \tex_scantokens:D
+              \exp_not:N \exp_args:Ne \exp_not:N \tex_scantokens:D
                 {
-                  \tex_global:D ####1
-                  \tex_def:D \exp_not:N #1 ####2
+                  \tex_global:D ##1
+                  \tex_def:D \exp_not:N #1 ##2
                     {
-                      ####3 \tl_to_str:n {#2}
+                      ##3 \tl_to_str:n {#2}
                       \c_backslash_str __debug_ \cs_to_str:N #1
-                      ####4 \tl_to_str:n {#3}
+                      ##4 \tl_to_str:n {#3}
                     }
                 }
             }
@@ -372,7 +372,7 @@
     }
   \cs_set_protected:Npn \__debug_patch_weird:Nnn #1#2#3
     {
-      \use:x
+      \use:e
         {
           \tex_endlinechar:D -1 \scan_stop:
           \exp_not:N \tex_scantokens:D
@@ -423,8 +423,8 @@
       \tl_concat:NNN
       \tl_gconcat:NNN
     }
-\cs_gset_protected:Npn \__kernel_tl_set:Nx  { \cs_set_nopar:Npx }
-\cs_gset_protected:Npn \__kernel_tl_gset:Nx { \cs_gset_nopar:Npx }
+\cs_gset_protected:Npn \__kernel_tl_set:Ne  { \cs_set_nopar:Npe }
+\cs_gset_protected:Npn \__kernel_tl_gset:Ne { \cs_gset_nopar:Npe }
   \__kernel_patch:nnn
     { \__kernel_chk_var_local:N #1 }
     { }
@@ -466,20 +466,21 @@
       \skip_set_eq:NN
       \skip_add:Nn
       \skip_sub:Nn
-      \__kernel_tl_set:Nx
+      \__kernel_tl_set:Ne
       \tl_clear:N
       \tl_set_eq:NN
       \tl_put_left:Nn
       \tl_put_left:NV
+      \tl_put_left:Nv
+      \tl_put_left:Ne
       \tl_put_left:No
-      \tl_put_left:Nx
       \tl_put_right:Nn
       \tl_put_right:NV
+      \tl_put_right:Nv
+      \tl_put_right:Ne
       \tl_put_right:No
-      \tl_put_right:Nx
       \tl_build_begin:N
       \tl_build_put_right:Nn
-      \tl_build_put_right:Nx
       \tl_build_put_left:Nn
       \vbox_set:Nn
       \vbox_set_top:Nn
@@ -530,20 +531,21 @@
       \skip_gset_eq:NN
       \skip_gadd:Nn
       \skip_gsub:Nn
-      \__kernel_tl_gset:Nx
+      \__kernel_tl_gset:Ne
       \tl_gclear:N
       \tl_gset_eq:NN
       \tl_gput_left:Nn
       \tl_gput_left:NV
+      \tl_gput_left:Nv
+      \tl_gput_left:Ne
       \tl_gput_left:No
-      \tl_gput_left:Nx
       \tl_gput_right:Nn
       \tl_gput_right:NV
+      \tl_gput_right:Nv
+      \tl_gput_right:Ne
       \tl_gput_right:No
-      \tl_gput_right:Nx
       \tl_build_gbegin:N
       \tl_build_gput_right:Nn
-      \tl_build_gput_right:Nx
       \tl_build_gput_left:Nn
       \vbox_gset:Nn
       \vbox_gset_top:Nn
@@ -564,7 +566,6 @@
       \muskip_const:Nn
       \skip_const:Nn
       \tl_const:Nn
-      \tl_const:Nx
     }
   \__kernel_patch:nnn
     { \__kernel_chk_flag_exist:n {#1} }
@@ -601,7 +602,7 @@
   \__kernel_patch:nnn
     { }
     {
-      \__kernel_debug_log:x
+      \__kernel_debug_log:e
         { Defining~\token_to_str:N #1~ \msg_line_context: }
     }
     { \__kernel_chk_if_free_cs:N }
@@ -609,7 +610,7 @@
     {
       \cs_if_free:NF #4
         {
-          \__kernel_debug_log:x
+          \__kernel_debug_log:e
             {
               Variant~\token_to_str:N #4~%
               already~defined;~ not~ changing~ it~ \msg_line_context:
@@ -621,14 +622,14 @@
   \__kernel_patch:nnn
     {
       \cs_if_exist:cF { \c__keys_code_root_str #1 }
-        { \__kernel_debug_log:x { Defining~key~#1~\msg_line_context: } }
+        { \__kernel_debug_log:e { Defining~key~#1~\msg_line_context: } }
     }
     { }
     { \__keys_cmd_set_direct:nn }
   \__kernel_patch:nnn
     { }
     {
-      \__kernel_debug_log:x
+      \__kernel_debug_log:e
         { Defining~message~ #1 / #2 ~\msg_line_context: }
     }
     { \__msg_chk_free:nn }
@@ -652,7 +653,7 @@
     {
       \__regex_trace_push:nnN { regex } { 1 } \__regex_escape_use:nnnn
       \group_begin:
-        \__kernel_tl_set:Nx \l__regex_internal_a_tl
+        \__kernel_tl_set:Ne \l__regex_internal_a_tl
           { \__regex_trace_pop:nnN { regex } { 1 } \__regex_escape_use:nnnn }
         \use_none:nnn
     }
@@ -674,7 +675,7 @@
     { \__regex_build_for_cs:n }
   \__kernel_patch:nnn
     {
-      \__regex_trace:nnx { regex } { 2 }
+      \__regex_trace:nne { regex } { 2 }
         {
           regex~new~state~
           L=\int_use:N \l__regex_left_state_int ~ -> ~
@@ -696,24 +697,24 @@
   \__kernel_patch:nnn
     {
       \__regex_trace_push:nnN { regex } { 1 } \__regex_match:n
-      \__regex_trace:nnx { regex } { 1 } { analyzing~query~token~list }
+      \__regex_trace:nne { regex } { 1 } { analyzing~query~token~list }
     }
     { \__regex_trace_pop:nnN { regex } { 1 } \__regex_match:n }
     { \__regex_match:n }
   \__kernel_patch:nnn
     {
       \__regex_trace_push:nnN { regex } { 1 } \__regex_match_cs:n
-      \__regex_trace:nnx { regex } { 1 } { analyzing~query~token~list }
+      \__regex_trace:nne { regex } { 1 } { analyzing~query~token~list }
     }
     { \__regex_trace_pop:nnN { regex } { 1 } \__regex_match_cs:n }
     { \__regex_match_cs:n }
   \__kernel_patch:nnn
-    { \__regex_trace:nnx { regex } { 1 } { initializing } }
+    { \__regex_trace:nne { regex } { 1 } { initializing } }
     { }
     { \__regex_match_init: }
   \__kernel_patch:nnn
     {
-      \__regex_trace:nnx { regex } { 2 }
+      \__regex_trace:nne { regex } { 2 }
         { state~\int_use:N \l__regex_curr_state_int }
     }
     { }
@@ -734,7 +735,7 @@
     {
         \char_set_catcode_parameter:N \#
         \tex_endlinechar:D -1 \scan_stop:
-        \exp_args:Nx \tex_scantokens:D
+        \exp_args:Ne \tex_scantokens:D
           {
             \tex_global:D \cs_prefix_spec:N #1 \tex_def:D \exp_not:N #1
               \cs_parameter_spec:N #1
@@ -746,7 +747,7 @@
     {
       \tl_map_inline:nn {#1}
         {
-          \exp_args:NNx \__kernel_patch:Nn ##1
+          \exp_args:NNe \__kernel_patch:Nn ##1
             {
               { \c_hash_str 1 }
               {
@@ -805,7 +806,7 @@
     {
       \tl_map_inline:nn {#1}
         {
-          \exp_args:NNx \__kernel_patch:Nn ##1
+          \exp_args:NNe \__kernel_patch:Nn ##1
             {
               {
                 \exp_not:N \__kernel_chk_expr:nNnN { \c_hash_str 1 }
@@ -850,7 +851,7 @@
     {
       \tl_map_inline:nn {#1}
         {
-          \exp_args:NNx \__kernel_patch:Nn ##1
+          \exp_args:NNe \__kernel_patch:Nn ##1
             {
               {
                 \exp_not:N \__kernel_chk_expr:nNnN { \c_hash_str 1 }
@@ -883,7 +884,7 @@
     {
       \clist_map_inline:nn { :nNnT , :nNnF , :nNnTF , _p:nNn }
         {
-          \exp_args:Ncx \__kernel_patch:Nn { #1 ##1 }
+          \exp_args:Nce \__kernel_patch:Nn { #1 ##1 }
             {
               {
                 \exp_not:N \__kernel_chk_expr:nNnN { \c_hash_str 1 }
@@ -905,7 +906,7 @@
     {
       \clist_map_inline:nn { :nT , :nF , :nTF , _p:n }
         {
-          \exp_args:Ncx \__kernel_patch:Nn { #1 ##1 }
+          \exp_args:Nce \__kernel_patch:Nn { #1 ##1 }
             {
               {
                 \exp_not:N \__kernel_chk_expr:nNnN { \c_hash_str 1 }
diff --git a/Master/texmf-dist/tex/latex/l3kernel/l3doc.cls b/Master/texmf-dist/tex/latex/l3kernel/l3doc.cls
index 663dc7b91e5..4191b7df9c2 100644
--- a/Master/texmf-dist/tex/latex/l3kernel/l3doc.cls
+++ b/Master/texmf-dist/tex/latex/l3kernel/l3doc.cls
@@ -120,9 +120,6 @@
 \cs_generate_variant:Nn \tl_replace_once:Nnn { Noo }
 \cs_generate_variant:Nn \tl_set_rescan:Nnn { NnV }
 \cs_generate_variant:Nn \tl_to_str:n { f , o }
-\cs_generate_variant:Nn \prop_get:NnNTF { Nx }
-\cs_generate_variant:Nn \prop_put:Nnn { Nx }
-\cs_generate_variant:Nn \prop_gput:Nnn { NVx }
 \prg_new_protected_conditional:Npnn \__codedoc_if_almost_str:n #1 { TF , T , F }
   {
     \int_compare:nNnTF
@@ -135,7 +132,7 @@
 \cs_new_protected:Npn \__codedoc_trim_right:Nn #1#2
   {
     \cs_set:Npn \__codedoc_tmp:w ##1 #2 ##2 \q_stop { \exp_not:n {##1} }
-    \__kernel_tl_set:Nx #1 { \exp_after:wN \__codedoc_tmp:w #1 #2 \q_stop }
+    \__kernel_tl_set:Ne #1 { \exp_after:wN \__codedoc_tmp:w #1 #2 \q_stop }
   }
 \cs_generate_variant:Nn \__codedoc_trim_right:Nn { No }
 \prg_new_protected_conditional:Npnn \__codedoc_str_if_begin:nn #1#2 { TF , T , F }
@@ -156,7 +153,7 @@
           #1 \g__codedoc_module_name_tl
       }
   }
-\cs_new_protected:Npx \__codedoc_replace_at_at_aux:Nn #1#2
+\cs_new_protected:Npe \__codedoc_replace_at_at_aux:Nn #1#2
   {
     \tl_replace_all:Nnn #1 { \token_to_str:N @ } { @ }
     \tl_replace_all:Nnn #1 { \token_to_str:N _ } { _ }
@@ -190,7 +187,7 @@
               \__codedoc_trim_right:Nn \l__codedoc_detect_internals_tl _
               \__codedoc_trim_right:Nn \l__codedoc_detect_internals_tl :
               \__codedoc_trim_right:No \l__codedoc_detect_internals_tl { \token_to_str:N : }
-              \msg_warning:nnxxx { l3doc } { foreign-internal }
+              \msg_warning:nneee { l3doc } { foreign-internal }
                 { \tl_to_str:N \l__codedoc_detect_internals_cs_tl }
                 { \tl_to_str:N \l__codedoc_detect_internals_tl }
                 { \tl_to_str:N \g__codedoc_module_name_tl }
@@ -270,14 +267,14 @@
     \__codedoc_if_almost_str:nTF {#1}
       {
         \__codedoc_key_get_base_TF:nN {#1} \l__codedoc_tmpa_tl
-        \__kernel_tl_set:Nx #2
+        \__kernel_tl_set:Ne #2
           { \__codedoc_split_function_do:on \l__codedoc_tmpa_tl { \__codedoc_base_form_aux:nnN } }
       }
       { \tl_set:Nn #2 {#1} }
   }
-\cs_new:Npx \__codedoc_key_get_base_TF:nN #1#2
+\cs_new:Npe \__codedoc_key_get_base_TF:nN #1#2
   {
-    \__kernel_tl_set:Nx #2 { \exp_not:N \tl_to_str:n {#1} }
+    \__kernel_tl_set:Ne #2 { \exp_not:N \tl_to_str:n {#1} }
     \tl_if_in:NoF #2 { \tl_to_str:n {:} }
       { \exp_not:N \prg_break: }
     \tl_if_in:onT { #2 z } { \tl_to_str:n {TF} z }
@@ -320,7 +317,7 @@
         \tl_if_head_eq_charcode:nNTF {#4} :
           { #2 {#1} }
           {
-            \use:x
+            \use:e
               {
                 \exp_not:n {#3}
                 { \__codedoc_base_form_aux:nnN {#4} {#5} #6 }
@@ -492,7 +489,7 @@
 \cs_gset_eq:NN \endverbatim \endVerbatim
 \cs_set_protected:Npn \ifnot@excluded
   {
-    \exp_args:Nxx \expanded@notin
+    \exp_args:Nee \expanded@notin
       { \c_backslash_str \tl_to_str:N \macro@namepart , }
       { \exp_args:NV \tl_to_str:n \index@excludelist }
   }
@@ -708,7 +705,7 @@
         \verbatim@font
         \__codedoc_if_almost_str:VT \l__codedoc_cmd_tl
           {
-            \__kernel_tl_set:Nx \l__codedoc_cmd_tl { \tl_to_str:N \l__codedoc_cmd_tl }
+            \__kernel_tl_set:Ne \l__codedoc_cmd_tl { \tl_to_str:N \l__codedoc_cmd_tl }
             \bool_if:NT \g__codedoc_cs_break_bool
               {
                 \regex_replace_all:nnN
@@ -727,13 +724,13 @@
        {
         \quark_if_no_value:NF \l__codedoc_cmd_index_tl
           {
-            \__kernel_tl_set:Nx \l__codedoc_cmd_tl
+            \__kernel_tl_set:Ne \l__codedoc_cmd_tl
               { \c_backslash_str \exp_not:o { \l__codedoc_cmd_index_tl } }
           }
         \exp_args:No \__codedoc_key_get:n { \l__codedoc_cmd_tl }
         \quark_if_no_value:NF \l__codedoc_cmd_module_tl
           {
-            \__kernel_tl_set:Nx \l__codedoc_index_module_tl
+            \__kernel_tl_set:Ne \l__codedoc_index_module_tl
               { \tl_to_str:N \l__codedoc_cmd_module_tl }
           }
         \__codedoc_special_index_module:ooonN
@@ -811,29 +808,29 @@
   }
 \cs_new_protected:Npn \__codedoc_get_hyper_target:nN #1#2
   {
-    \__kernel_tl_set:Nx #2 { \tl_to_str:n {#1} }
-    \tl_replace_all:Nxn #2 { \c_underscore_str } { / }
-    \tl_remove_all:Nx   #2 { \c_backslash_str }
+    \__kernel_tl_set:Ne #2 { \tl_to_str:n {#1} }
+    \tl_replace_all:Nen #2 { \c_underscore_str } { / }
+    \tl_remove_all:Ne   #2 { \c_backslash_str }
     \tl_put_left:Nn #2 { doc/function// }
   }
-\cs_generate_variant:Nn \__codedoc_get_hyper_target:nN { o , x }
+\cs_generate_variant:Nn \__codedoc_get_hyper_target:nN { o , e }
 \cs_new_protected:Npn \__codedoc_names_get_seq:nN #1#2
   {
-    \__kernel_tl_set:Nx \l__codedoc_tmpa_tl { \tl_to_str:n {#1} }
+    \__kernel_tl_set:Ne \l__codedoc_tmpa_tl { \tl_to_str:n {#1} }
     \bool_if:NTF \l__codedoc_names_verb_bool
       {
         \seq_clear:N #2
         \seq_put_right:NV #2 \l__codedoc_tmpa_tl
       }
       {
-        \tl_remove_all:Nx \l__codedoc_tmpa_tl
+        \tl_remove_all:Ne \l__codedoc_tmpa_tl
           { \iow_char:N \^^M \c_percent_str }
-        \tl_remove_all:Nx \l__codedoc_tmpa_tl { \tl_to_str:n { ^ ^ A } }
-        \tl_remove_all:Nx \l__codedoc_tmpa_tl { \iow_char:N \^^I }
-        \tl_remove_all:Nx \l__codedoc_tmpa_tl { \iow_char:N \^^M }
+        \tl_remove_all:Ne \l__codedoc_tmpa_tl { \tl_to_str:n { ^ ^ A } }
+        \tl_remove_all:Ne \l__codedoc_tmpa_tl { \iow_char:N \^^I }
+        \tl_remove_all:Ne \l__codedoc_tmpa_tl { \iow_char:N \^^M }
         \__codedoc_detect_internals:N \l__codedoc_tmpa_tl
         \__codedoc_replace_at_at:N \l__codedoc_tmpa_tl
-        \exp_args:NNx \seq_set_from_clist:Nn #2
+        \exp_args:NNe \seq_set_from_clist:Nn #2
           { \tl_to_str:N \l__codedoc_tmpa_tl }
       }
   }
@@ -857,14 +854,14 @@
         \tl_if_head_eq_charcode:nNTF {#2} :
           { \__codedoc_names_parse_aux:nnn {#4} {#4} { \scan_stop: } }
           {
-            \exp_args:Nx \__codedoc_names_parse_aux:nnn
+            \exp_args:Ne \__codedoc_names_parse_aux:nnn
               { \__codedoc_base_form_aux:nnN {#1} {#2} #3 }
               {#1} {#2}
           }
       }
       {
         \bool_if:NT \l__codedoc_macro_TF_bool
-          { \msg_error:nnx { l3doc } { no-signature-TF } {#4} }
+          { \msg_error:nne { l3doc } { no-signature-TF } {#4} }
         \__codedoc_names_parse_aux:nnn {#4} {#4} { \scan_stop: }
       }
   }
@@ -895,12 +892,12 @@
     \str_if_eq:VnTF \l__codedoc_tmpa_tl { \scan_stop: }
       {
         \seq_gclear:N \g__codedoc_variants_seq
-        \__codedoc_names_typeset_auxii:x { \g__codedoc_base_name_tl }
+        \__codedoc_names_typeset_auxii:e { \g__codedoc_base_name_tl }
       }
       {
         \seq_gset_eq:NN \g__codedoc_variants_seq #1
         \seq_gpop:NN \g__codedoc_variants_seq \l__codedoc_tmpb_tl
-        \__codedoc_names_typeset_auxii:x
+        \__codedoc_names_typeset_auxii:e
           { \g__codedoc_base_name_tl : \l__codedoc_tmpb_tl }
       }
   }
@@ -908,7 +905,7 @@
   {
     \bool_if:NT \l__codedoc_macro_pTF_bool
       {
-        \__codedoc_names_typeset_block:xN
+        \__codedoc_names_typeset_block:eN
           { \__codedoc_predicate_from_base:n {#1} }
           \c_false_bool
       }
@@ -916,14 +913,14 @@
       { \__codedoc_names_typeset_block:nN {#1} \c_false_bool }
     \__codedoc_names_typeset_block:nN {#1} \l__codedoc_macro_TF_bool
   }
-\cs_generate_variant:Nn \__codedoc_names_typeset_auxii:n { x }
+\cs_generate_variant:Nn \__codedoc_names_typeset_auxii:n { e }
 \cs_new_protected:Npn \__codedoc_names_typeset_block:nN
   {
     \int_compare:nNnTF \l__codedoc_nested_macro_int = 0
       { \__codedoc_typeset_function_block:nN }
       { \__codedoc_macro_typeset_block:nN }
   }
-\cs_generate_variant:Nn \__codedoc_names_typeset_block:nN { x }
+\cs_generate_variant:Nn \__codedoc_names_typeset_block:nN { e }
 \prg_new_conditional:Npnn \__codedoc_if_macro_internal:n #1 { p , T , F , TF }
   {
     \bool_if:NTF \l__codedoc_macro_internal_set_bool
@@ -950,7 +947,7 @@
           \seq_set_eq:NN \l__codedoc_tmpa_seq ##1
           \seq_pop:NN \l__codedoc_tmpa_seq \l__codedoc_tmpa_tl
           \seq_get:NN \l__codedoc_tmpa_seq \l__codedoc_tmpb_tl
-          \exp_args:NNx
+          \exp_args:NNe
         \group_end:
         #1
           {
@@ -1023,7 +1020,7 @@
     \exp_args:No \__codedoc_date_compare:nNnT
       {#1} > { \c_sys_year_int - \c_sys_month_int - \c_sys_day_int }
       {
-        \msg_error:nnxx { l3doc } { future-date }
+        \msg_error:nnee { l3doc } { future-date }
           { \tl_to_str:N \l__codedoc_macro_argument_tl }
           {#1}
       }
@@ -1156,9 +1153,9 @@
   }
 \cs_new_protected:Npn \__codedoc_typeset_function_block:nN #1#2
   {
-    \__codedoc_function_index:x
+    \__codedoc_function_index:e
       { #1 \bool_if:NT #2 { \tl_to_str:n {TF} } }
-    \__codedoc_function_label:xN {#1} #2
+    \__codedoc_function_label:eN {#1} #2
     #1
     \bool_if:NT #2 { \__codedoc_typeset_TF: }
     \__codedoc_typeset_expandability:
@@ -1166,13 +1163,13 @@
       { \__codedoc_typeset_variant_list:nN {#1} #2 }
     \\
   }
-\cs_generate_variant:Nn \__codedoc_typeset_function_block:nN { x }
+\cs_generate_variant:Nn \__codedoc_typeset_function_block:nN { e }
 \cs_new_protected:Npn \__codedoc_function_index:n #1
   {
     \seq_gput_right:Nn \g_doc_functions_seq {#1}
     \__codedoc_special_index:nn {#1} { usage }
   }
-\cs_generate_variant:Nn \__codedoc_function_index:n { x }
+\cs_generate_variant:Nn \__codedoc_function_index:n { e }
 \cs_new_protected:Npn \__codedoc_typeset_expandability:
   {
     &
@@ -1224,7 +1221,7 @@
   {
     \bool_if:NF \l__codedoc_no_label_bool
       {
-        \__codedoc_get_hyper_target:xN
+        \__codedoc_get_hyper_target:eN
           {
             \exp_not:n {#1}
             \bool_if:NT #2 { \tl_to_str:n {TF} }
@@ -1233,7 +1230,7 @@
         \exp_args:No \label { \l__codedoc_tmpa_tl }
       }
   }
-\cs_generate_variant:Nn \__codedoc_function_label:nN { x }
+\cs_generate_variant:Nn \__codedoc_function_label:nN { e }
 \cs_new:Npn \__codedoc_typeset_dates:
   {
     \bool_lazy_and:nnF
@@ -1417,7 +1414,7 @@
           \l__codedoc_macro_do_not_index_tl
         \exp_args:NNV \seq_set_from_clist:Nn
           \l__codedoc_tmpa_seq \l__codedoc_macro_do_not_index_tl
-        \__kernel_tl_set:Nx \l__codedoc_macro_do_not_index_tl
+        \__kernel_tl_set:Ne \l__codedoc_macro_do_not_index_tl
           { \seq_use:Nn \l__codedoc_tmpa_seq { , } }
         \exp_args:NV \DoNotIndex \l__codedoc_macro_do_not_index_tl
       }
@@ -1445,7 +1442,7 @@
     \__codedoc_macro_single:nNN {#1} \c_true_bool #2
     \seq_if_empty:NF \g__codedoc_variants_seq
       {
-        \__codedoc_macro_typeset_variant_list:xN
+        \__codedoc_macro_typeset_variant_list:eN
           { \__codedoc_get_function_name:n {#1} } #2
       }
   }
@@ -1455,13 +1452,13 @@
     \seq_map_inline:Nn \g__codedoc_variants_seq
       { \__codedoc_macro_single:nNN { #1 : ##1 } \c_false_bool #2 }
   }
-\cs_generate_variant:Nn \__codedoc_macro_typeset_variant_list:nN { x }
+\cs_generate_variant:Nn \__codedoc_macro_typeset_variant_list:nN { e }
 \cs_new_protected:Npn \__codedoc_macro_single:nNN #1#2#3
   {
     \tl_set:Nn \saved@macroname {#1}
     \__codedoc_macro_typeset_one:nN {#1} #3
     \bool_if:NT #3 { \DoNotIndex {#1} }
-    \exp_args:Nx \__codedoc_macro_index:nN
+    \exp_args:Ne \__codedoc_macro_index:nN
       { #1 \bool_if:NT #3 { \tl_to_str:n { TF } } }
       #2
   }
@@ -1495,7 +1492,7 @@
 \cs_new_protected:Npn \__codedoc_print_macroname:nN #1#2
   {
     \strut
-    \__codedoc_get_hyper_target:xN
+    \__codedoc_get_hyper_target:eN
       {
         \exp_not:n {#1}
         \bool_if:NT #2 { \tl_to_str:n {TF} }
@@ -1565,7 +1562,7 @@
   { \__codedoc_test_missing:n {#1} }
 \cs_new_protected:Npn \__codedoc_test_missing:n #1
   {
-    \__codedoc_test_missing_aux:Nxn
+    \__codedoc_test_missing_aux:Nen
       \g__codedoc_missing_tests_prop
       { \seq_use:Nn \l__codedoc_names_seq { , } }
       { { \g_file_curr_name_str \c_space_tl (#1) } }
@@ -1577,7 +1574,7 @@
       { \tl_set:Nn \l__codedoc_tmpa_tl {#3} }
     \prop_put:Nno #1 {#2} \l__codedoc_tmpa_tl
   }
-\cs_generate_variant:Nn \__codedoc_test_missing_aux:Nnn { Nx }
+\cs_generate_variant:Nn \__codedoc_test_missing_aux:Nnn { Ne }
 \cs_new_protected:Npn \__codedoc_macro_end:
   {
     \endtrivlist
@@ -1596,7 +1593,7 @@
      {
        \seq_set_filter:NNn \l__codedoc_tmpa_seq \l__codedoc_names_seq
          { ! \__codedoc_if_macro_internal_p:n {##1} }
-       \seq_gput_right:Nx \g__codedoc_not_tested_seq
+       \seq_gput_right:Ne \g__codedoc_not_tested_seq
          {
            \seq_use:Nn \l__codedoc_tmpa_seq { , }
            \bool_if:NTF \l__codedoc_macro_pTF_bool {~(pTF)}
@@ -1644,10 +1641,10 @@
         \bool_if:NTF \l__codedoc_macro_var_bool {variable} {function}
         \int_compare:nNnTF \l__codedoc_tmpa_int = 1 {~is~} {s~are~}
         documented~on~page~
-        \__codedoc_get_hyper_target:xN
+        \__codedoc_get_hyper_target:eN
           { \seq_item:Nn \g__codedoc_nested_names_seq { 1 } }
           \l__codedoc_tmpa_tl
-        \exp_args:Nx \pageref { \l__codedoc_tmpa_tl } .
+        \exp_args:Ne \pageref { \l__codedoc_tmpa_tl } .
       }
     \seq_gclear:N \g__codedoc_nested_names_seq
   }
@@ -1698,6 +1695,31 @@
   {
     \NewDocumentEnvironment{NOTE}{m}{\comment}{\endcomment}
   }
+\providecommand\Hy@footnote@currentHref{}
+\prop_new:N\g__codedoc_fnmark_prop
+\cs_new_protected:Npn \__codedoc_fn_store:
+ {
+   \prop_gput:Nee\g__codedoc_fnmark_prop
+     {fn\int_use:N\c@footnote}{{\Hy@footnote@currentHref}{\int_use:N\c@footnote}}
+ }
+\cs_new_protected:Npn \__codedoc_fn_restore:n  #1
+ {
+   \prop_get:NnN \g__codedoc_fnmark_prop {fn#1}\l__codedoc_tmpa_tl
+   \tl_gset:Ne\Hy@footnote@currentHref
+     {\exp_last_unbraced:NV\use_i:nn \l__codedoc_tmpa_tl }
+   \setcounter{footnote}{\exp_last_unbraced:NV\use_ii:nn \l__codedoc_tmpa_tl}
+ }
+
+\cs_generate_variant:Nn \hook_gput_next_code:nn {ne}
+\cs_new_protected:Npn \__codedoc_fn_footnote:nn #1 #2
+  {
+    \footnotemark
+    \__codedoc_fn_store:
+    \hook_gput_next_code:ne {env/#1/after}
+      {\exp_not:N\__codedoc_fn_restore:n{\int_use:N\c@footnote}{\exp_not:n{\footnotetext{#2}}}}}
+
+\AddToHook{env/function/begin}{\def\footnote{\__codedoc_fn_footnote:nn{function}}}
+\AddToHook{env/variable/begin}{\def\footnote{\__codedoc_fn_footnote:nn{variable}}}
 \newenvironment{TemplateInterfaceDescription}[1]
   {
     \subsection{The~object~type~`#1'}
@@ -1806,7 +1828,7 @@
     \@tempswatrue
     \if@partsw
       \@tempswafalse
-      \cs_set:Npx \@tempb {#1}
+      \cs_set:Npe \@tempb {#1}
       \clist_map_inline:Nn \@partlist
         {
           \if_meaning:w \@tempa \@tempb
@@ -1827,7 +1849,7 @@
       \part{\currentfile}
       {
         \cs_set_eq:NN \ttfamily\relax
-        \cs_gset:Npx \filekey
+        \cs_gset:Npe \filekey
           { \filekey,~ \thepart = { \ttfamily \currentfile } }
       }
       \DocInput{\currentfile}
@@ -1960,12 +1982,14 @@
 \tl_new:N \l__codedoc_doc_def_tl
 \tl_new:N \l__codedoc_doc_undef_tl
 \tl_new:N \l__codedoc_undoc_def_tl
+\tl_const:Nn \c__codedoc_iow_separator_tl { ---- }
+\tl_const:Nn \c__codedoc_iow_midrule_tl  { -- }
 \cs_new_protected:Npn \__codedoc_show_functions_defined:
   {
     \bool_lazy_and:nnT
       { \g__codedoc_typeset_implementation_bool } { \g__codedoc_checkfunc_bool }
       {
-        \iow_term:x { \c__codedoc_iow_separator_tl \iow_newline: }
+        \iow_term:e { \c__codedoc_iow_separator_tl \iow_newline: }
         \iow_open:Nn \g__codedoc_func_iow { \c_sys_jobname_str .cmds }
 
         \tl_clear:N \l__codedoc_doc_def_tl
@@ -1975,12 +1999,12 @@
           {
             \seq_if_in:NnTF \g_doc_macros_seq {##1}
               {
-                \tl_put_right:Nx \l__codedoc_doc_def_tl
+                \tl_put_right:Ne \l__codedoc_doc_def_tl
                   { ##1 \iow_newline: }
                 \iow_now:Nn \g__codedoc_func_iow { > ~ ##1 }
               }
               {
-                \tl_put_right:Nx \l__codedoc_doc_undef_tl
+                \tl_put_right:Ne \l__codedoc_doc_undef_tl
                   { ##1 \iow_newline: }
                 \iow_now:Nn \g__codedoc_func_iow { ! ~ ##1 }
               }
@@ -1989,7 +2013,7 @@
           {
             \seq_if_in:NnF \g_doc_functions_seq {##1}
               {
-                \tl_put_right:Nx \l__codedoc_undoc_def_tl
+                \tl_put_right:Ne \l__codedoc_undoc_def_tl
                   { ##1 \iow_newline: }
                 \iow_now:Nn \g__codedoc_func_iow { ? ~ ##1 }
               }
@@ -2008,7 +2032,7 @@
           \l__codedoc_undoc_def_tl
 
         \iow_close:N \g__codedoc_func_iow
-        \iow_term:x { \c__codedoc_iow_separator_tl }
+        \iow_term:e { \c__codedoc_iow_separator_tl }
       }
   }
 \AtEndDocument { \__codedoc_show_functions_defined: }
@@ -2044,7 +2068,7 @@
                 \iow_newline:
                 \space\space\space\space\space\space * ~ ##1
               }
-            \tl_put_right:Nx \l__codedoc_tmpa_tl
+            \tl_put_right:Ne \l__codedoc_tmpa_tl
               {
                 \iow_newline: \iow_newline:
                 The~ following~ macro(s)~ have~ incomplete~ tests:
@@ -2062,7 +2086,7 @@
                 \iow_newline:
                 \space\space\space\space ##1
               }
-            \tl_put_right:Nx \l__codedoc_tmpa_tl
+            \tl_put_right:Ne \l__codedoc_tmpa_tl
               {
                 \iow_newline:
                 \iow_newline:
@@ -2089,7 +2113,7 @@
       \HD@savedestfalse \HD@target
     \group_end:
   }
-\cs_set_nopar:Npx \theCodelineNo
+\cs_set_nopar:Npe \theCodelineNo
   {
     \group_begin:
       \exp_not:N \HD@savedestfalse
@@ -2098,7 +2122,7 @@
   }
 \bool_new:N \l__codedoc_allow_indexing_bool
 \bool_set_true:N \l__codedoc_allow_indexing_bool
-\use:x
+\use:e
   {
     \exp_not:n { \cs_set_nopar:Npn \@starttoc #1 }
       {
@@ -2137,7 +2161,7 @@
   { \AtEndDocument { \msg_info:nn { l3doc } { print-index-howto } } }
 \cs_gset_protected:Npn \it@is@a #1
   {
-    \use:x
+    \use:e
       {
         \__codedoc_special_index_module:nnnnN
           {#1}
@@ -2164,7 +2188,7 @@
 \tl_new:N \l__codedoc_index_escaped_key_tl
 \cs_new_protected:Npn \__codedoc_special_index_module:nnnnN #1#2#3#4#5
   {
-    \use:x
+    \use:e
       {
         \exp_not:n { \__codedoc_special_index_aux:nnnnnn {#1} {#2} }
           \tl_if_empty:nTF {#3}
@@ -2214,7 +2238,7 @@
   }
 \group_begin:
 \char_set_active_eq:NN - \scan_stop:
-\tl_const:Nx \c__codedoc_active_minus_tl { \char_generate:nn { `- } { 13 } }
+\tl_const:Ne \c__codedoc_active_minus_tl { \char_generate:nn { `- } { 13 } }
 \group_end:
 \cs_new_eq:NN \__codedoc_old_hdpindex:nn \hdpindex
 \cs_new_eq:NN \__codedoc_old_hdclindex:nnn \hdclindex
@@ -2225,7 +2249,7 @@
 \cs_new_protected:Npn \__codedoc_hdindex:nn #1#2
   {
     \tl_set:Nn \l__codedoc_tmpa_tl {#2}
-    \tl_replace_all:Nxn \l__codedoc_tmpa_tl
+    \tl_replace_all:Nen \l__codedoc_tmpa_tl
       { \exp_not:V \c__codedoc_active_minus_tl \exp_not:V \c__codedoc_active_minus_tl }
       { -- }
     \seq_set_split:NnV \l__codedoc_tmpa_seq { -- } \l__codedoc_tmpa_tl
@@ -2239,16 +2263,16 @@
     \tl_replace_all:Nnn \l__codedoc_tmpa_tl { MMMM } { \use_none:nn }
     \tl_if_in:NnT \l__codedoc_tmpa_tl { MMMD }
       {
-        \tl_replace_all:Nxn \l__codedoc_tmpa_tl
+        \tl_replace_all:Nen \l__codedoc_tmpa_tl
           { \exp_not:V \c__codedoc_active_minus_tl MMMD } { - MMMD }
         \tl_replace_all:Nnn \l__codedoc_tmpa_tl { - MMMD } { \__codedoc_hdindex_aux:w }
       }
-    \use:x { \exp_not:n {#1} { \exp_not:V \l__codedoc_tmpa_tl } }
+    \use:e { \exp_not:n {#1} { \exp_not:V \l__codedoc_tmpa_tl } }
   }
 \cs_new_protected:Npn \__codedoc_hdindex_aux:w #1 M { }
 \cs_new_protected:Npn \__codedoc_special_index_set:Nn #1#2
   {
-    \__kernel_tl_set:Nx #1 { \tl_to_str:n {#2} }
+    \__kernel_tl_set:Ne #1 { \tl_to_str:n {#2} }
     \__codedoc_if_almost_str:nTF {#2}
       {
         \tl_replace_all:Non #1 { \tl_to_str:n { __ } }
@@ -2257,7 +2281,7 @@
             \token_to_str:N \_ \token_to_str:N \_
             \token_to_str:N \verb * \verbatimchar
           }
-        \exp_args:Nx \tl_map_inline:nn
+        \exp_args:Ne \tl_map_inline:nn
           { \tl_to_str:N \verbatimchar \token_to_str:N _ }
           {
             \tl_replace_all:Nnn #1 {##1}
@@ -2266,7 +2290,7 @@
                 \token_to_str:N \verb * \verbatimchar
               }
           }
-        \__kernel_tl_set:Nx #1
+        \__kernel_tl_set:Ne #1
           {
             \token_to_str:N \verb * \verbatimchar
             #1 \verbatimchar
@@ -2284,14 +2308,14 @@
   {
     \tl_map_inline:nn { \quotechar \actualchar \encapchar \levelchar \bslash }
       {
-        \tl_replace_all:Nxn #1
+        \tl_replace_all:Nen #1
           { \tl_to_str:N ##1 } { \quotechar \tl_to_str:N ##1 }
       }
   }
 \cs_new_protected:Npn \__codedoc_key_get:n #1
   {
     \__codedoc_key_get_base:nN {#1} \l__codedoc_index_macro_tl
-    \__kernel_tl_set:Nx \l__codedoc_index_key_tl
+    \__kernel_tl_set:Ne \l__codedoc_index_key_tl
       { \tl_to_str:N \l__codedoc_index_macro_tl }
     \tl_clear:N \l__codedoc_index_module_tl
     \tl_if_in:NoTF \l__codedoc_index_key_tl { \tl_to_str:n { __ } }
@@ -2314,14 +2338,14 @@
   }
 \cs_new_protected:Npn \__codedoc_key_pop:
   {
-    \__kernel_tl_set:Nx \l__codedoc_index_key_tl
+    \__kernel_tl_set:Ne \l__codedoc_index_key_tl
       { \tl_tail:N \l__codedoc_index_key_tl }
   }
 \cs_new_protected:Npn \__codedoc_key_trim_module:n #1
   {
     \cs_set:Npn \__codedoc_tmpa:w ##1 #1 ##2 \q_stop
       { \exp_not:n {##1} }
-    \__kernel_tl_set:Nx \l__codedoc_index_module_tl
+    \__kernel_tl_set:Ne \l__codedoc_index_module_tl
       { \exp_after:wN \__codedoc_tmpa:w \l__codedoc_index_module_tl #1 \q_stop }
   }
 \cs_new_protected:Npn \__codedoc_key_drop_underscores:
@@ -2340,7 +2364,7 @@
   }
 \cs_new_protected:Npn \__codedoc_key_var:
   {
-    \exp_args:Nx \tl_if_head_eq_charcode:nNTF
+    \exp_args:Ne \tl_if_head_eq_charcode:nNTF
       { \exp_args:No \str_tail:n \l__codedoc_index_key_tl } _
       {
         \str_case:fn { \str_head:N \l__codedoc_index_key_tl }
@@ -2372,7 +2396,7 @@
       }
   }
 \clist_new:N \g__codedoc_non_modules_clist
-\clist_gset:Nx \g__codedoc_non_modules_clist
+\clist_gset:Ne \g__codedoc_non_modules_clist
   {
     \tl_to_str:n
       {
diff --git a/Master/texmf-dist/tex/latex/l3packages/l3keys2e/l3keys2e.sty b/Master/texmf-dist/tex/latex/l3packages/l3keys2e/l3keys2e.sty
index ff77a32ec1a..fde7919c757 100644
--- a/Master/texmf-dist/tex/latex/l3packages/l3keys2e/l3keys2e.sty
+++ b/Master/texmf-dist/tex/latex/l3packages/l3keys2e/l3keys2e.sty
@@ -32,7 +32,7 @@
       }%
     \endinput
   }
-\ProvidesExplPackage{l3keys2e}{2023-08-29}{}
+\ProvidesExplPackage{l3keys2e}{2023-10-10}{}
   {LaTeX2e option processing using LaTeX3 keys}
 \cs_if_exist:NT \ProcessKeysOptions
   { \file_input_stop: }
@@ -52,7 +52,7 @@
           {
             unknown .code:n =
               {
-                \msg_error:nnxx { keyvalue } { option-unknown }
+                \msg_error:nnee { keyvalue } { option-unknown }
                   { \l_keys_key_str } { \@currname }
               }
           }
@@ -90,7 +90,7 @@
           {
             \clist_map_inline:cn { opt@ \@currname . \@currext }
               {
-                \keys_if_exist:nxTF {#1} { \__keys_latexe_remove_equals:n {##1} }
+                \keys_if_exist:neTF {#1} { \__keys_latexe_remove_equals:n {##1} }
                   { \clist_put_right:Nn \l__keys_latexe_options_clist {##1} }
                   { \clist_put_right:Nn \@unusedoptionlist {##1} }
               }
@@ -101,7 +101,7 @@
   {
     \clist_map_inline:Nn \@classoptionslist
       {
-        \keys_if_exist:nxT {#1} { \__keys_latexe_remove_equals:n {##1} }
+        \keys_if_exist:neT {#1} { \__keys_latexe_remove_equals:n {##1} }
           {
             \clist_put_right:Nn \l__keys_latexe_options_clist {##1}
             \clist_remove_all:Nn \@unusedoptionlist {##1}
diff --git a/Master/texmf-dist/tex/latex/l3packages/xfp/xfp.sty b/Master/texmf-dist/tex/latex/l3packages/xfp/xfp.sty
index d24c07489b1..d7f5038e6df 100644
--- a/Master/texmf-dist/tex/latex/l3packages/xfp/xfp.sty
+++ b/Master/texmf-dist/tex/latex/l3packages/xfp/xfp.sty
@@ -32,7 +32,7 @@
       }%
     \endinput
   }
-\ProvidesExplPackage{xfp}{2023-08-29}{}
+\ProvidesExplPackage{xfp}{2023-10-10}{}
   {L3 Floating point unit}
 \ProvideExpandableDocumentCommand \fpeval { m } { \fp_eval:n {#1} }
 \ProvideExpandableDocumentCommand \inteval { m } { \int_eval:n {#1} }
diff --git a/Master/texmf-dist/tex/latex/l3packages/xfrac/xfrac.sty b/Master/texmf-dist/tex/latex/l3packages/xfrac/xfrac.sty
index d10d8c35743..e6e40464d91 100644
--- a/Master/texmf-dist/tex/latex/l3packages/xfrac/xfrac.sty
+++ b/Master/texmf-dist/tex/latex/l3packages/xfrac/xfrac.sty
@@ -34,7 +34,7 @@
     \endinput
   }
 \RequirePackage{amstext,graphicx,l3keys2e,textcomp,xparse,xtemplate}
-\ProvidesExplPackage{xfrac}{2023-08-29}{}
+\ProvidesExplPackage{xfrac}{2023-10-10}{}
   {L3 Experimental split-level fractions}
 \keys_define:nn { xfrac }
   {
@@ -159,11 +159,11 @@
     \mode_if_math:TF
       {
         \cs_set_eq:NN \__xfrac_text_or_math:n \text
-        \cs_set:Npx \__xfrac_denominator_font_change:
+        \cs_set:Npe \__xfrac_denominator_font_change:
           { \tex_fam:D \l__xfrac_denominator_font_tl }
-        \cs_set:Npx \__xfrac_numerator_font_change:
+        \cs_set:Npe \__xfrac_numerator_font_change:
           { \tex_fam:D \l__xfrac_numerator_font_tl }
-        \cs_set:Npx \__xfrac_slash_symbol_font_change:
+        \cs_set:Npe \__xfrac_slash_symbol_font_change:
           { \tex_fam:D \l__xfrac_slash_symbol_font_tl }
       }
       {
diff --git a/Master/texmf-dist/tex/latex/l3packages/xparse/xparse.sty b/Master/texmf-dist/tex/latex/l3packages/xparse/xparse.sty
index fed28004cc4..6dd25e9b1b3 100644
--- a/Master/texmf-dist/tex/latex/l3packages/xparse/xparse.sty
+++ b/Master/texmf-dist/tex/latex/l3packages/xparse/xparse.sty
@@ -60,7 +60,7 @@
       }
   }
 \ExplSyntaxOff
-\ProvidesExplPackage{xparse}{2023-08-29}{}
+\ProvidesExplPackage{xparse}{2023-10-10}{}
   {L3 Experimental document command parser}
 \clist_new:N \l__cmd_options_clist
 \DeclareOption* { \clist_put_right:NV \l__cmd_options_clist \CurrentOption }
@@ -78,7 +78,7 @@
       { \msg_redirect_module:nnn {#1} { info } { none } }
     \cs_new_protected:Npn \__cmd_unknown_argument_type_error:n ##1
       {
-        \msg_error:nnxx {#1} { unknown-argument-type }
+        \msg_error:nnee {#1} { unknown-argument-type }
           { \__cmd_environment_or_command: } { \tl_to_str:n {##1} }
       }
   }
@@ -95,7 +95,7 @@
         \__cmd_bad_def:wn
       }
   }
-\cs_new_protected:Npx \__cmd_normalize_type_g:w
+\cs_new_protected:Npe \__cmd_normalize_type_g:w
   { \exp_not:N \__cmd_normalize_type_G:w { \exp_not:V \c_novalue_tl } }
 \cs_new_protected:Npn \__cmd_normalize_type_G:w #1
   {
@@ -219,7 +219,7 @@
 \cs_gset_protected:Npn \__cmd_get_arg_spec_error:n #1
   {
     \bool_set_true:N \l__cmd_environment_bool
-    \str_set:Nx \l__cmd_environment_str {#1}
+    \str_set:Ne \l__cmd_environment_str {#1}
     \__cmd_get_arg_spec_error_aux:n
       { \cs_if_exist:cTF { \l__cmd_environment_str } }
   }
@@ -227,11 +227,11 @@
   {
     #1
       {
-        \msg_error:nnx { cmd } { non-xparse }
+        \msg_error:nne { cmd } { non-xparse }
           { \__cmd_environment_or_command: }
       }
       {
-        \msg_error:nnx { cmd } { unknown }
+        \msg_error:nne { cmd } { unknown }
           { \__cmd_environment_or_command: }
       }
   }
@@ -239,7 +239,7 @@
   {
     \__kernel_cmd_if_xparse:NTF #1
       {
-        \tl_set:Nx \ArgumentSpecification { \tl_item:Nn #1 { 2 } }
+        \tl_set:Ne \ArgumentSpecification { \tl_item:Nn #1 { 2 } }
         #2
       }
       {#3}
diff --git a/Master/texmf-dist/tex/latex/l3packages/xtemplate/xtemplate.sty b/Master/texmf-dist/tex/latex/l3packages/xtemplate/xtemplate.sty
index 15dc32c5465..9d524ce8838 100644
--- a/Master/texmf-dist/tex/latex/l3packages/xtemplate/xtemplate.sty
+++ b/Master/texmf-dist/tex/latex/l3packages/xtemplate/xtemplate.sty
@@ -32,10 +32,8 @@
       }%
     \endinput
   }
-\ProvidesExplPackage{xtemplate}{2023-08-29}{}
+\ProvidesExplPackage{xtemplate}{2023-10-10}{}
   {L3 Experimental prototype document functions}
-\cs_generate_variant:Nn \keys_define:nn { nx }
-\cs_generate_variant:Nn \tl_trim_spaces:n { e }
 \tl_const:Nn \c__xtemplate_code_root_tl      { template~code~>~ }
 \tl_const:Nn \c__xtemplate_defaults_root_tl  { template~defaults~>~ }
 \tl_const:Nn \c__xtemplate_instances_root_tl { template~instance~>~  }
@@ -83,7 +81,7 @@
     \int_compare:nNnTF {#2} = \l__xtemplate_tmp_tl
        {#3}
        {
-         \msg_error:nnxxx { xtemplate }
+         \msg_error:nneee { xtemplate }
            { argument-number-mismatch } {#1} { \l__xtemplate_tmp_tl } {#2}
        }
   }
@@ -92,7 +90,7 @@
     \cs_if_exist:cTF { \c__xtemplate_code_root_tl #1 / #2 }
       {#3}
       {
-        \msg_error:nnxx { xtemplate } { no-template-code }
+        \msg_error:nnee { xtemplate } { no-template-code }
           {#1} {#2}
       }
   }
@@ -100,21 +98,21 @@
   {
     \cs_if_exist:cTF { __xtemplate_store_value_ #1 :n }
       {#2}
-      { \msg_error:nnx { xtemplate } { unknown-keytype } {#1} }
+      { \msg_error:nne { xtemplate } { unknown-keytype } {#1} }
   }
 \cs_generate_variant:Nn \__xtemplate_execute_if_keytype_exist:nT { o }
 \cs_new_protected:Npn \__xtemplate_execute_if_type_exist:nT #1#2
   {
     \prop_if_in:NnTF \g__xtemplate_object_type_prop {#1}
       {#2}
-      { \msg_error:nnx { xtemplate } { unknown-object-type } {#1} }
+      { \msg_error:nne { xtemplate } { unknown-object-type } {#1} }
   }
 \cs_new_protected:Npn \__xtemplate_if_keys_exist:nnT #1#2#3
   {
     \cs_if_exist:cTF { \c__xtemplate_keytypes_root_tl #1 / #2 }
       {#3}
       {
-        \msg_error:nnxx { xtemplate } { unknown-template }
+        \msg_error:nnee { xtemplate } { unknown-template }
           {#1} {#2}
       }
    }
@@ -234,13 +232,13 @@
     \int_set:Nn \l__xtemplate_tmp_int {#2}
     \int_compare:nTF { 0 <= \l__xtemplate_tmp_int <= 9 }
       {
-        \msg_info:nnxx { xtemplate } { declare-object-type }
-          {#1} { \exp_not:V \l__xtemplate_tmp_int }
+        \msg_info:nnnV { xtemplate } { declare-object-type }
+          {#1} \l__xtemplate_tmp_int
         \prop_gput:NnV \g__xtemplate_object_type_prop {#1}
           \l__xtemplate_tmp_int
       }
       {
-        \msg_error:nnxx { xtemplate } { bad-number-of-arguments }
+        \msg_error:nnee { xtemplate } { bad-number-of-arguments }
           {#1} { \exp_not:V \l__xtemplate_tmp_int }
       }
   }
@@ -274,7 +272,7 @@
                 \seq_if_in:NoTF \l__xtemplate_key_order_seq
                   \l__xtemplate_key_name_tl
                   {
-                    \msg_error:nnx { xtemplate }
+                    \msg_error:nne { xtemplate }
                       { duplicate-key-interface }
                       { \l__xtemplate_key_name_tl }
                   }
@@ -289,7 +287,7 @@
       {
         \tl_if_empty:NT \l__xtemplate_keytype_arg_tl
           {
-            \msg_error:nnx { xtemplate }
+            \msg_error:nne { xtemplate }
               { keytype-requires-argument } {#1}
             \bool_set_true:N \l__xtemplate_error_bool
             \seq_map_break:
@@ -298,7 +296,7 @@
   }
 \cs_new:Npn \__xtemplate_parse_keys_elt_aux:
   {
-    \tl_set:Nx \l__xtemplate_tmp_tl
+    \tl_set:Ne \l__xtemplate_tmp_tl
       {
         \l__xtemplate_keytype_tl
         \tl_if_empty:NF \l__xtemplate_keytype_arg_tl
@@ -318,7 +316,7 @@
     \__xtemplate_parse_keys_elt:n {#1}
     \use:c { __xtemplate_store_value_ \l__xtemplate_keytype_tl :n } {#2}
   }
-\cs_new_protected:Npx \__xtemplate_split_keytype:n #1
+\cs_new_protected:Npe \__xtemplate_split_keytype:n #1
   {
     \exp_not:N \bool_set_false:N \exp_not:N \l__xtemplate_error_bool
     \tl_set:Nn \exp_not:N \l__xtemplate_tmp_tl {#1}
@@ -334,38 +332,38 @@
       }
       {
         \exp_not:N \bool_set_true:N \exp_not:N \l__xtemplate_error_bool
-        \msg_error:nnx { xtemplate } { missing-keytype } {#1}
+        \msg_error:nne { xtemplate } { missing-keytype } {#1}
       }
   }
-\use:x
+\use:e
   {
     \cs_new_protected:Npn \exp_not:N \__xtemplate_split_keytype_aux:w
-      ##1 \token_to_str:N : ##2 \s__xtemplate_stop
+      #1 \token_to_str:N : #2 \s__xtemplate_stop
       {
-        \tl_put_right:Nx \exp_not:N \l__xtemplate_key_name_tl
+        \tl_put_right:Ne \exp_not:N \l__xtemplate_key_name_tl
           {
             \exp_not:N \tl_trim_spaces:e
-              { \exp_not:N \tl_to_str:n {##1} }
+              { \exp_not:N \tl_to_str:n {#1} }
           }
-        \tl_if_in:nnTF {##2} { \token_to_str:N : }
+        \tl_if_in:nnTF {#2} { \token_to_str:N : }
           {
             \tl_put_right:Nn \exp_not:N \l__xtemplate_key_name_tl
               { \token_to_str:N : }
-            \exp_not:N \__xtemplate_split_keytype_aux:w ##2 \s__xtemplate_stop
+            \exp_not:N \__xtemplate_split_keytype_aux:w #2 \s__xtemplate_stop
           }
           {
             \exp_not:N \tl_if_empty:NTF \exp_not:N \l__xtemplate_key_name_tl
               {
-                \msg_error:nnx { xtemplate } { empty-key-name }
-                  { \token_to_str:N : ##2 }
+                \msg_error:nne { xtemplate } { empty-key-name }
+                  { \token_to_str:N : #2 }
               }
-              { \exp_not:N \__xtemplate_split_keytype_arg:n {##2} }
+              { \exp_not:N \__xtemplate_split_keytype_arg:n {#2} }
           }
       }
   }
 \cs_new_protected:Npn \__xtemplate_split_keytype_arg:n #1
   {
-    \tl_set:Nx \l__xtemplate_keytype_tl { \tl_trim_spaces:n {#1} }
+    \tl_set:Ne \l__xtemplate_keytype_tl { \tl_trim_spaces:n {#1} }
     \tl_clear:N \l__xtemplate_keytype_arg_tl
     \cs_set_protected:Npn \__xtemplate_split_keytype_arg_aux:n ##1
       {
@@ -376,11 +374,11 @@
               {
                 \tl_if_blank:nT {####1}
                   {
-                    \tl_set:Nx \l__xtemplate_keytype_tl
+                    \tl_set:Ne \l__xtemplate_keytype_tl
                       { \tl_trim_spaces:n {##1} }
                     \tl_if_blank:nF {####2}
                       {
-                        \tl_set:Nx \l__xtemplate_keytype_arg_tl
+                        \tl_set:Ne \l__xtemplate_keytype_arg_tl
                           { \use:n ####2 }
                       }
                     \seq_map_break:
@@ -454,15 +452,15 @@
     \__xtemplate_store_restrictions:n { #1 / #2 }
     \prop_map_inline:Nn \l__xtemplate_keytypes_prop
       {
-        \msg_error:nnxxx { xtemplate } { key-not-implemented }
+        \msg_error:nneee { xtemplate } { key-not-implemented }
           {##1} {#2} {#1}
       }
   }
 \cs_new_protected:Npn \__xtemplate_parse_vars_elt:n #1
-  { \msg_error:nnx { xtemplate } { key-no-variable } {#1} }
+  { \msg_error:nne { xtemplate } { key-no-variable } {#1} }
 \cs_new_protected:Npn \__xtemplate_parse_vars_elt:nnn #1#2#3
  {
-    \tl_set:Nx \l__xtemplate_key_name_tl
+    \tl_set:Ne \l__xtemplate_key_name_tl
       { \tl_trim_spaces:e { \tl_to_str:n {#2} } }
     \prop_get:NoNTF
       \l__xtemplate_keytypes_prop
@@ -473,7 +471,7 @@
         \__xtemplate_parse_vars_elt_aux:nn {#1} {#3}
         \prop_remove:NV \l__xtemplate_keytypes_prop \l__xtemplate_key_name_tl
       }
-      { \msg_error:nnx { xtemplate } { unknown-key } {#2} }
+      { \msg_error:nne { xtemplate } { unknown-key } {#2} }
   }
 \cs_new_protected:Npn \__xtemplate_parse_vars_elt_aux:nn #1#2
   {
@@ -487,7 +485,7 @@
       {
         \tl_if_blank:nTF {#2}
           {
-            \exp_args:Nnnx \__xtemplate_parse_vars_elt_aux:nnn
+            \exp_args:Nnne \__xtemplate_parse_vars_elt_aux:nnn
               {#1} { global } { \tl_trim_spaces:n {#3} }
           }
           { \msg_error:nnn { xtemplate } { bad-variable } { #2 global #3 } }
@@ -511,7 +509,7 @@
                       \exp_not:c
                         { cs_ \str_if_eq:nnT {#1} { global } { g } set:Npn }
                       { \exp_not:o \l__xtemplate_keytype_arg_tl }
-                      {####1}
+                      {##1}
                   }
               }
             \prop_put:Non \l__xtemplate_vars_prop
@@ -525,7 +523,7 @@
                   {
                     \exp_not:c
                       { cs_ \str_if_eq:nnT {#1} { global } { g } set:Npn }
-                      \exp_not:N #3 { \UseInstance {####1} }
+                      \exp_not:N #3 { \UseInstance {##1} }
                   }
               }
             \prop_put:Non \l__xtemplate_vars_prop
@@ -546,12 +544,12 @@
             \prop_put:Non \l__xtemplate_vars_prop
               \l__xtemplate_key_name_tl {#2#3}
           }
-          { \msg_error:nnx { xtemplate } { bad-variable } { #2#3 } }
+          { \msg_error:nne { xtemplate } { bad-variable } { #2#3 } }
       }
   }
 \cs_new_protected:Npn \__xtemplate_parse_vars_elt_key:nn #1#2
   {
-    \keys_define:nx { template / #1 }
+    \keys_define:ne { template / #1 }
       { \l__xtemplate_key_name_tl #2 }
   }
 \cs_new:Npn \__xtemplate_map_var_type:
@@ -572,7 +570,7 @@
   {
     \clist_set:No \l__xtemplate_tmp_clist { \l__xtemplate_keytype_arg_tl }
     \prop_put:Non \l__xtemplate_vars_prop \l__xtemplate_key_name_tl { }
-    \keys_define:nx { template / #1 } { \l__xtemplate_key_name_tl .choice: }
+    \keys_define:ne { template / #1 } { \l__xtemplate_key_name_tl .choice: }
     \keyval_parse:nnn
       { \__xtemplate_implement_choice_elt:n }
       { \__xtemplate_implement_choice_elt:nnn {#1} }
@@ -584,18 +582,18 @@
       {
         \clist_map_inline:Nn \l__xtemplate_tmp_clist
           {
-            \msg_error:nnx { xtemplate } { choice-not-implemented }
+            \msg_error:nne { xtemplate } { choice-not-implemented }
               {##1}
           }
       }
   }
 \cs_new_protected:Npn \__xtemplate_implement_choices_default:
   {
-    \tl_set:Nx \l__xtemplate_tmp_tl
+    \tl_set:Ne \l__xtemplate_tmp_tl
       { \l__xtemplate_key_name_tl \c_space_tl \l__xtemplate_tmp_tl }
     \prop_if_in:NoF \l__xtemplate_vars_prop \l__xtemplate_tmp_tl
       {
-        \tl_set:Nx \l__xtemplate_tmp_tl
+        \tl_set:Ne \l__xtemplate_tmp_tl
           { \l__xtemplate_key_name_tl \c_space_tl \l__xtemplate_tmp_tl }
         \prop_if_in:NoF \l__xtemplate_vars_prop \l__xtemplate_tmp_tl
           {
@@ -604,7 +602,7 @@
             \__xtemplate_split_keytype_arg:o \l__xtemplate_tmp_tl
             \prop_get:NoN \l__xtemplate_values_prop \l__xtemplate_key_name_tl
               \l__xtemplate_tmp_tl
-            \msg_error:nnxxx { xtemplate } { unknown-default-choice }
+            \msg_error:nneee { xtemplate } { unknown-default-choice }
               { \l__xtemplate_key_name_tl } { \l__xtemplate_key_name_tl }
               { \l__xtemplate_keytype_arg_tl }
           }
@@ -620,7 +618,7 @@
             \prop_get:NoN \l__xtemplate_keytypes_prop \l__xtemplate_key_name_tl
               \l__xtemplate_tmp_tl
             \__xtemplate_split_keytype_arg:o \l__xtemplate_tmp_tl
-            \msg_error:nnxxx { xtemplate } { unknown-choice }
+            \msg_error:nneee { xtemplate } { unknown-choice }
               { \l__xtemplate_key_name_tl } {#2}
               { \l__xtemplate_keytype_arg_tl }
           }
@@ -635,7 +633,7 @@
             \prop_get:NoN \l__xtemplate_keytypes_prop \l__xtemplate_key_name_tl
               \l__xtemplate_tmp_tl
             \__xtemplate_split_keytype_arg:o \l__xtemplate_tmp_tl
-            \msg_error:nnxxx { xtemplate } { unknown-choice }
+            \msg_error:nneee { xtemplate } { unknown-choice }
               { \l__xtemplate_key_name_tl } {#2}
               { \l__xtemplate_keytype_arg_tl }
           }
@@ -643,15 +641,15 @@
   }
 \cs_new_protected:Npn \__xtemplate_implement_choice_elt_aux:nnn #1#2#3
   {
-    \keys_define:nx { template / #1 }
+    \keys_define:ne { template / #1 }
       { \l__xtemplate_key_name_tl / #2 .code:n = { \exp_not:n {#3} } }
-    \tl_set:Nx \l__xtemplate_tmp_tl
+    \tl_set:Ne \l__xtemplate_tmp_tl
       { \l__xtemplate_key_name_tl \c_space_tl #2 }
     \prop_put:Non \l__xtemplate_vars_prop \l__xtemplate_tmp_tl {#3}
   }
 \cs_new_protected:Npn \__xtemplate_implement_choice_elt:n #1
   {
-    \msg_error:nnxxx { xtemplate } { choice-requires-code }
+    \msg_error:nneee { xtemplate } { choice-requires-code }
       { \l__xtemplate_key_name_tl } {#1}
   }
 \cs_new_protected:Npn \__xtemplate_declare_restricted:nnnn #1#2#3#4
@@ -694,11 +692,11 @@
 \cs_new_protected:Npn \__xtemplate_parse_values_elt:n #1
   {
     \bool_set_true:N \l__xtemplate_error_bool
-    \msg_error:nnx { xtemplate } { key-no-value } {#1}
+    \msg_error:nne { xtemplate } { key-no-value } {#1}
   }
 \cs_new_protected:Npn \__xtemplate_parse_values_elt:nn #1#2
   {
-    \tl_set:Nx \l__xtemplate_key_name_tl
+    \tl_set:Ne \l__xtemplate_key_name_tl
       { \tl_trim_spaces:e { \tl_to_str:n {#1} } }
     \prop_get:NoNTF \l__xtemplate_keytypes_prop \l__xtemplate_key_name_tl
       \l__xtemplate_tmp_tl
@@ -712,7 +710,7 @@
           { \__xtemplate_parse_values_elt_aux:n {#2} }
       }
       {
-        \msg_error:nnx { xtemplate } { unknown-key }
+        \msg_error:nne { xtemplate } { unknown-key }
           { \l__xtemplate_key_name_tl }
       }
   }
@@ -752,7 +750,7 @@
         \prop_put:Nnn \l__xtemplate_values_prop { from~template } {#2}
         \__xtemplate_store_values:n { #1 / #3 / #4 }
         \__xtemplate_convert_to_assignments:
-        \cs_set_protected:cpx { \c__xtemplate_instances_root_tl #1 / #3 / #4 }
+        \cs_set_protected:cpe { \c__xtemplate_instances_root_tl #1 / #3 / #4 }
           {
             \exp_not:N \__xtemplate_assignments_push:n
               { \exp_not:o \l__xtemplate_assignments_tl }
@@ -776,7 +774,7 @@
           { \c__xtemplate_instances_root_tl #1 / #2 / #3 }
       }
       {
-        \msg_error:nnxx { xtemplate } { unknown-instance }
+        \msg_error:nnee { xtemplate } { unknown-instance }
           {#1} {#3}
       }
   }
@@ -791,7 +789,7 @@
           {#2} {#3} {#4}
       }
       {
-        \msg_error:nnxx { xtemplate } { unknown-instance }
+        \msg_error:nnee { xtemplate } { unknown-instance }
           {#1} {#3}
       }
   }
@@ -827,7 +825,7 @@
             \tl_set:Nn \l__xtemplate_key_name_tl {#1}
             \use:c { __xtemplate_assign_ \l__xtemplate_keytype_tl : }
           }
-          { \msg_error:nnx { xtemplate } { unknown-attribute } {#1} }
+          { \msg_error:nne { xtemplate } { unknown-attribute } {#1} }
       }
   }
 \cs_generate_variant:Nn \__xtemplate_convert_to_assignments_aux:nn { no }
@@ -866,7 +864,7 @@
     \__xtemplate_if_key_value:oTF \l__xtemplate_value_tl
       {
         \__xtemplate_key_to_value:
-        \tl_put_right:Nx \l__xtemplate_assignments_tl
+        \tl_put_right:Ne \l__xtemplate_assignments_tl
           {
             \exp_not:c { #1 _eq:NN }
             \exp_not:o \l__xtemplate_var_tl
@@ -874,7 +872,7 @@
           }
       }
       {
-        \tl_put_right:Nx \l__xtemplate_assignments_tl
+        \tl_put_right:Ne \l__xtemplate_assignments_tl
           {
             \exp_not:c { #1 _ \l__xtemplate_value_tl :N }
             \exp_not:o \l__xtemplate_var_tl
@@ -883,16 +881,16 @@
   }
 \cs_new_protected:Npn \__xtemplate_assign_choice:
   {
-    \__xtemplate_assign_choice_aux:xF
+    \__xtemplate_assign_choice_aux:eF
       { \l__xtemplate_key_name_tl \c_space_tl \l__xtemplate_value_tl }
       {
-        \__xtemplate_assign_choice_aux:xF
+        \__xtemplate_assign_choice_aux:eF
           { \l__xtemplate_key_name_tl \c_space_tl unknown }
           {
             \prop_get:NoN \l__xtemplate_keytypes_prop \l__xtemplate_key_name_tl
               \l__xtemplate_tmp_tl
             \__xtemplate_split_keytype_arg:o \l__xtemplate_tmp_tl
-            \msg_error:nnxxx { xtemplate } { unknown-choice }
+            \msg_error:nneee { xtemplate } { unknown-choice }
               { \l__xtemplate_key_name_tl } { \l__xtemplate_value_tl }
               { \l__xtemplate_keytype_arg_tl }
           }
@@ -906,7 +904,7 @@
       \l__xtemplate_tmp_tl
       { \tl_put_right:No \l__xtemplate_assignments_tl \l__xtemplate_tmp_tl }
   }
-\cs_generate_variant:Nn \__xtemplate_assign_choice_aux:nF { x }
+\cs_generate_variant:Nn \__xtemplate_assign_choice_aux:nF { e }
 \cs_new_protected:Npn \__xtemplate_assign_function:
   {
     \bool_if:NTF \l__xtemplate_global_bool
@@ -915,7 +913,7 @@
   }
 \cs_new_protected:Npn \__xtemplate_assign_function_aux:N #1
   {
-    \tl_put_right:Nx \l__xtemplate_assignments_tl
+    \tl_put_right:Ne \l__xtemplate_assignments_tl
       {
         \cs_generate_from_arg_count:NNnn
           \exp_not:o \l__xtemplate_var_tl
@@ -932,7 +930,7 @@
   }
 \cs_new_protected:Npn \__xtemplate_assign_instance_aux:N #1
   {
-    \tl_put_right:Nx \l__xtemplate_assignments_tl
+    \tl_put_right:Ne \l__xtemplate_assignments_tl
       {
         \exp_not:N #1 \exp_not:o \l__xtemplate_var_tl
           {
@@ -983,14 +981,14 @@
     \__xtemplate_if_key_value:oTF \l__xtemplate_value_tl
       {
         \__xtemplate_key_to_value:
-        \tl_put_right:Nx \l__xtemplate_assignments_tl
+        \tl_put_right:Ne \l__xtemplate_assignments_tl
           {
             #1 \exp_not:o \l__xtemplate_var_tl
               \exp_not:o \l__xtemplate_value_tl
           }
       }
       {
-        \tl_put_right:Nx \l__xtemplate_assignments_tl
+        \tl_put_right:Ne \l__xtemplate_assignments_tl
           {
             #2 \exp_not:o \l__xtemplate_var_tl
               { \exp_not:o \l__xtemplate_value_tl }
@@ -1007,7 +1005,7 @@
   {
     \__xtemplate_if_key_value:oT \l__xtemplate_value_tl
       { \__xtemplate_key_to_value: }
-    \tl_put_right:Nx \l__xtemplate_assignments_tl
+    \tl_put_right:Ne \l__xtemplate_assignments_tl
       {
         #1 \exp_not:o \l__xtemplate_var_tl
          { \exp_not:o \l__xtemplate_value_tl }
@@ -1017,7 +1015,7 @@
   { \exp_after:wN \__xtemplate_key_to_value_auxi:w \l__xtemplate_value_tl }
 \cs_new_protected:Npn \__xtemplate_key_to_value_auxi:w \KeyValue #1
   {
-    \tl_set:Nx \l__xtemplate_tmp_tl { \tl_trim_spaces:e { \tl_to_str:n {#1} } }
+    \tl_set:Ne \l__xtemplate_tmp_tl { \tl_trim_spaces:e { \tl_to_str:n {#1} } }
     \prop_get:NoNTF
       \l__xtemplate_vars_prop
       \l__xtemplate_tmp_tl
@@ -1027,7 +1025,7 @@
           \s__xtemplate_mark global \q__xtemplate_nil \s__xtemplate_stop
       }
       {
-        \msg_error:nnx { xtemplate } { unknown-attribute }
+        \msg_error:nne { xtemplate } { unknown-attribute }
           { \l__xtemplate_tmp_tl }
       }
   }
@@ -1046,7 +1044,7 @@
   {
     \str_if_eq:nnTF {#1} {#3}
       { \__xtemplate_use_template:nnn {#3} {#4} {#5} }
-      { \msg_error:nnxx { xtemplate } { type-mismatch } {#1} {#3} }
+      { \msg_error:nnee { xtemplate } { type-mismatch } {#1} {#3} }
 }
 \cs_new_protected:Npn \__xtemplate_use_instance_aux:nn #1#2
   {
@@ -1064,7 +1062,7 @@
           \__xtemplate_if_instance_exist:nnnTF {#1} { } {#2}
             { \use:c { \c__xtemplate_instances_root_tl #1 / / #2 } }
             {
-              \msg_error:nnxx { xtemplate } { unknown-instance }
+              \msg_error:nnee { xtemplate } { unknown-instance }
                 {#1} {#2}
             }
         }
@@ -1111,7 +1109,7 @@
   }
 \cs_new_protected:Npn \__xtemplate_show:Nnnn #1#2#3#4
   {
-    \msg_show:nnxxxx { xtemplate } { show-attribute }
+    \msg_show:nneeee { xtemplate } { show-attribute }
       { \tl_to_str:n {#2} }
       { \tl_to_str:n {#3} }
       { \tl_to_str:n {#4} }
@@ -1122,7 +1120,7 @@
     \__xtemplate_if_instance_exist:nnnT {#1} {#2} {#3}
       {
         \__xtemplate_recover_values:n { #1 / #2 / #3 }
-        \msg_show:nnxxxx { xtemplate } { show-values }
+        \msg_show:nneeee { xtemplate } { show-values }
           { \tl_to_str:n {#1} }
           { \tl_to_str:n {#2} }
           { \tl_to_str:n {#3} }