witharrows (6nov17)

git-svn-id: svn://tug.org/texlive/trunk@45707 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 362 insertions, 430 deletions

diff --git a/Master/texmf-dist/tex/latex/witharrows/witharrows.sty b/Master/texmf-dist/tex/latex/witharrows/witharrows.sty
index c3bd9a31d67..5f9619ed32c 100644
--- a/Master/texmf-dist/tex/latex/witharrows/witharrows.sty
+++ b/Master/texmf-dist/tex/latex/witharrows/witharrows.sty
@@ -1,341 +1,328 @@
-% This work may be distributed and modified under the
-% conditions of the LaTeX Project Public License, either version 1.3
-% of this license or (at your option) any later version.
-% The latest version of this license is in
-%   http://mirrors.ctan.org/help/Catalogue/licenses.lppl.html
-% and version 1.3 or later is part of all distributions of LaTeX
-% version 2005/12/01 or later.
-
-
-% The author of this work is F. Pantigny (fpantigny at wanadoo point fr)
-
-\NeedsTeXFormat{LaTeX2e}[1994/06/01]
-
-
+%%
+%% This is file `witharrows.sty',
+%% generated with the docstrip utility.
+%%
+%% The original source files were:
+%%
+%% witharrows.dtx  (with options: `package')
+%% 
+%% Copyright (C) 2017 by F. Pantigny
+%% 
+%% This file may be distributed and/or modified under the
+%% conditions of the LaTeX Project Public License, either
+%% version 1.3 of this license or (at your option) any later
+%% version.  The latest version of this license is in:
+%% 
+%%      http://www.latex-project.org/lppl.txt
+%% 
+%% and version 1.3 or later is part of all distributions of
+%% LaTeX version 2005/12/01 or later.
+%% 
+\def\myfileversion{1.1}
+\def\myfiledate{2017/11/06}
 \RequirePackage{l3keys2e}
-
 \ProvidesExplPackage
-  {WithArrows}
-  {2017/08/09}
-  {1.0}
-  {Draws arrows for explanations on the right side of a alignment.} 
-
-
+  {witharrows}
+  {\myfiledate}
+  {\myfileversion}
+  {Draws arrows for explanations on the right}
 \RequirePackage{expl3}
 \RequirePackage{xparse}
-
 \RequirePackage{tikz}
-\usetikzlibrary{calc}
-\usetikzlibrary{arrows.meta}
-\usetikzlibrary{bending}
-
-
-
+\usetikzlibrary{calc,arrows.meta,bending}
 \RequirePackage{footnote}
-
-
-
-% There is a style for the tips of arrow because someone will use this style
-% if he wants draw an arrow directly with a Tikz command in his document (probably using the Tikz nodes created by
-% {WithArrows} in the \halign.
-\tikzset{TipsOfWithArrows/.style= { > = {Straight~Barb[scale=1.2,bend]}} }
-
-
-% The following variables are for the options ; these options can be set at 3 levels : see the groups of keys defined in
-% the \keys_define:nn comand below.
-
-% if the beginning of the arrow use a "r" option (if not, it's a "l" option)
-\bool_new:N \l_wa_initial_r_bool
-\bool_set_true:N \l_wa_initial_r_bool
-
-% if the end of the arrow use a "r" option (if not, it's à "l" option)
-\bool_new:N \l_wa_final_r_bool
-\bool_set_true:N \l_wa_final_r_bool
-
-% if the arrow use a "i" option (in this case the options "l" and "r" for the ends are meaningless)
-\bool_new:N \l_wa_i_bool
-\bool_set_false:N \l_wa_i_bool
-
-% to translate the whole arrow to the right
-\dim_new:N \l_wa_xoffset_dim 
-\dim_set:Nn \l_wa_xoffset_dim {3mm}
-
-% to indicate if the nodes will be drawn (in red) ; useful only for debugging
-\bool_new:N \l_wa_shownodes_bool
-\bool_set_false:N \l_wa_shownodes_bool
-
-% to indiate if the elements of the \halign will be composed with \displaystyle
-\bool_new:N \l_wa_displaystyle_bool
-\bool_set_false:N \l_wa_displaystyle_bool
-
-% will contains the Tikz options used to draw the arrow
-\tl_clear_new:N \l_wa_options_tikz_tl
-% At each possible level for the options ("global", "env" or "local : see below), the new values will be appended
-% on the right of the token list \l_wa_options_tikz_tl
-
-% will be raised when a key controling position of the arrow has been set in the same list of key
-% useful in order to raise an error if 2 incompatibles keys are specified at the same level
-\bool_new:N \l_wa_position_key_already_set_bool
-\bool_set_false:N \l_wa_position_key_already_set_bool
-
-% This Tikz style is for the nodes created automatically in the \halign.
-\tikzstyle{wa_node_style}=[rectangle,
+\tikzstyle{__wa_node_style}=[rectangle,
                            inner~sep = 0 pt,
                            minimum~height = 3 pt,
                            minimum~width = 0pt,
-                           red,  % red... but will be drawn only if shownodes=true
-                           \bool_if:NT \l_wa_shownodes_bool {draw}]
-
-
-
-% There are 3 levels where keys can be set :
-% with \WithArrowsOptions{...} : this level will be called "global" level ;
-% with \begin{WithArrows}[...] : this level will be called "env" level ;
-% with \Arrow[...] : this level will be called "local" level.
-
-% That's why there is 3 groups of keys named "global", "env" and "local".
-
-% Before each \keys_set_groups:nnn, we execute a \keys_set_filter:nnn with group "secondary"
-% Thus, an unknown key will raise an error. Furthermore, the "primary" keys (those which are not in the 
-% group "secondary") will be set first : it's useful to raise an error if, for example, keys "i" and "group"
-% are set at the same level (which is incoherent).
-
-% There is also the group named "jump" (with only one key : "jump") for technical reasons.
-\keys_define:nn {WithArrows} 
-    { % the key named "jump" will be extracted in the \Arrow command 
-      jump     .groups:n          = {jump,secondary},
-      jump     .code:n            = {\int_set:Nn \l_jump_int {#1}
-                                     \int_compare:nNnF \l_jump_int > 0
-                                         {\msg_error:nn {WithArrows} {The~option~"jump"~must~be~non~negative}}},
-      jump     .value_required:n  = true,
-      %
-      % 0 = t = \vtop , 1 = c = \vcenter, 2 = b = \vbox
-      pos         .groups:n         = {global,env,secondary},
-      pos         .int_set:N        = \l_wa_pos_int,
-      pos         .initial:n        = 0,
-      pos         .value_required:n = true,
-      %
-      t           .groups:n         = {global,env,kown},
-      t           .meta:n           = {pos=0},
-      c           .groups:n         = {global,env,kown},
-      c           .meta:n           = {pos=1},
-      b           .groups:n         = {global,env,kown},
-      b           .meta:n           = {pos=2},
-      %
-      % if the user wants to give a new name to the \Arrow command (and the name \Arrow remains free)
+                           red,
+                           \bool_if:NT \l__wa_shownodes_bool {draw}]
+\tikzset{TipsOfWithArrows/.style= { > = {Straight~Barb[scale=1.2,bend]}} }
+\cs_if_free:NT \spread@equation
+    {\cs_set:Npn \spread@equation{\openup\jot
+                                  \cs_set_eq:NN \spread@equation \prg_do_nothing}}
+\seq_new:N \g__wa_position_in_the_tree_seq
+\seq_gput_right:Nn \g__wa_position_in_the_tree_seq 1
+\int_new:N \g__wa_last_env_int
+\skip_new:N \l__wa_interline_skip
+\bool_new:N \l__wa_MoreColumns_bool
+\int_new:N \l__wa_pos_int
+\bool_new:N \l__wa_initial_r_bool
+\bool_set_true:N \l__wa_initial_r_bool
+\bool_new:N \l__wa_final_r_bool
+\bool_set_true:N \l__wa_final_r_bool
+\bool_new:N \l__wa_i_bool
+\dim_new:N \l__wa_xoffset_dim
+\dim_set:Nn \l__wa_xoffset_dim {3mm}
+\bool_new:N \l__wa_shownodes_bool
+\bool_new:N \l__wa_shownodenames_bool
+\bool_new:N \l__wa_displaystyle_bool
+\tl_clear_new:N \l__wa_options_tikz_tl
+\bool_new:N \l__wa_position_key_already_set_bool
+\seq_new:N \g__wa_stack_counter_arrows_seq
+\int_new:N \g__wa_arrow_int
+\seq_new:N \g__wa_stack_counter_lines_seq
+\int_new:N \g__wa_line_int
+\seq_new:N \g__wa_stack_counter_lines_bis_seq
+\int_new:N \g__wa_line_bis_int
+
+\keys_define:nn {WithArrows}
+    { jump  .groups:n   = {jump,secondary},
+      jump  .code:n     = {\int_set:Nn \l__wa_jump_int {#1}
+                           \int_compare:nNnF \l__wa_jump_int > 0
+                               {\msg_error:nn {witharrows}
+                                              {The~option~"jump"~must~be~non~negative}}},
+      jump  .value_required:n  = true,
+      t   .groups:n          = {global,env,secondary},
+      t   .code:n            = {\int_set:Nn \l__wa_pos_int 0},
+      t   .value_forbidden:n = true,
+      c   .groups:n          = {global,env,secondary},
+      c   .code:n            = {\int_set:Nn \l__wa_pos_int 1},
+      c   .value_forbidden:n = true,
+      b   .groups:n          = {global,env,secondary},
+      b   .code:n            = {\int_set:Nn \l__wa_pos_int 2},
+      b   .value_forbidden:n = true,
+      MoreColumns .groups:n          = {global,env,secondary},
+      MoreColumns .bool_set:N        = \l__wa_MoreColumns_bool,
+      MoreColumns .default:n         = true,
+      MoreColumns .value_forbidden:n = true,
       CommandName .groups:n         = {global,env,secondary},
-      CommandName .tl_set:N         = \l_wa_CommandName_tl,
+      CommandName .tl_set:N         = \l__wa_CommandName_tl,
       CommandName .initial:n        = {Arrow},
       CommandName .value_required:n = true,
-      %
       displaystyle .groups:n          = {global,env,secondary},
-      displaystyle .bool_set:N        = \l_wa_displaystyle_bool,
-      displaystyle .value_forbidden:n = true,
-      %
+      displaystyle .bool_set:N        = \l__wa_displaystyle_bool,
       %
       shownodes .groups:n          = {global,env,secondary},
-      shownodes .bool_set:N        = \l_wa_shownodes_bool,
+      shownodes .bool_set:N        = \l__wa_shownodes_bool,
       shownodes .default:n         = true,
-      shownodes .value_forbidden:n = true, 
-      %
-      jot       .groups:n          = {env,secondary},  % don't put "global"
-      jot       .dim_set:N         = \jot, % \jot is a LaTeX parameter for the distance between 2 lines in displaymath
+      shownodenames .groups:n          = {global,env,secondary},
+      shownodenames .bool_set:N        = \l__wa_shownodenames_bool,
+      shownodenames .default:n         = true,
+      jot       .groups:n          = {env,secondary},
+      jot       .dim_set:N         = \jot,
       jot       .value_required:n  = true,
-      %
+      interline   .groups:n         = {env,secondary},
+      interline   .skip_set:N       = \l__wa_interline_skip,
+      interline   .initial:n        = \c_zero_skip,
+      interline   .value_required:n = true,
       xoffset  .groups:n          = {global,env,local,secondary},
-      xoffset  .dim_set:N         = \l_wa_xoffset_dim,
-      xoffset  .value_required:n  = true,           
-      %
+      xoffset  .dim_set:N         = \l__wa_xoffset_dim,
+      xoffset  .value_required:n  = true,
       tikz     .groups:n          = {global,env,local,secondary},
-      tikz     .code:n            = {\tl_put_right:Nn \l_wa_options_tikz_tl {,#1}},
+      tikz     .code:n            = {\tl_put_right:Nn \l__wa_options_tikz_tl {,#1}},
       tikz     .value_required:n  = true,
-      %
       ll       .groups:n          = {global,env,local,secondary},
-      ll       .value_forbidden:n = true, 
+      ll       .value_forbidden:n = true,
       ll       .default:n         = true,
-      ll       .code:n            = {\bool_if:NT \l_wa_position_key_already_set_bool
-                                       {\msg_error:nn {WithArrows} {Two~options~are~incompatible}}
-                                     \bool_if:NT \l_wa_group_bool
-                                       {\msg_error:nn {WithArrows} {Option~incompatible~with~group}}
-                                     \bool_set_true:N \l_wa_position_key_already_set_bool
-                                     \bool_set_false:N \l_wa_initial_r_bool
-                                     \bool_set_false:N \l_wa_final_r_bool
-                                     \bool_set_false:N \l_wa_i_bool },
-      %
+      ll       .code:n            = {\bool_if:NT \l__wa_position_key_already_set_bool
+                                       {\msg_error:nn {witharrows}
+                                                      {Two~options~are~incompatible}}
+                                     \bool_if:NT \l__wa_group_bool
+                                       {\msg_error:nn {witharrows}
+                                                      {Option~incompatible~with~group}}
+                                     \bool_set_true:N \l__wa_position_key_already_set_bool
+                                     \bool_set_false:N \l__wa_initial_r_bool
+                                     \bool_set_false:N \l__wa_final_r_bool
+                                     \bool_set_false:N \l__wa_i_bool },
       lr       .groups:n          = {global,env,local,secondary},
       lr       .value_forbidden:n = true,
-      lr       .default:n         = true, 
-      lr       .code:n            = {\bool_if:NT \l_wa_position_key_already_set_bool
-                                       {\msg_error:nn {WithArrows} {Two~options~are~incompatible}}
-                                     \bool_if:NT \l_wa_group_bool
-                                       {\msg_error:nn {WithArrows} {Option~incompatible~with~group}}
-                                     \bool_set_true:N \l_wa_position_key_already_set_bool
-                                     \bool_set_false:N \l_wa_initial_r_bool
-                                     \bool_set_true:N  \l_wa_final_r_bool
-                                     \bool_set_false:N \l_wa_i_bool},
-      %
+      lr       .default:n         = true,
+      lr       .code:n            = {\bool_if:NT \l__wa_position_key_already_set_bool
+                                       {\msg_error:nn {witharrows}
+                                                      {Two~options~are~incompatible}}
+                                     \bool_if:NT \l__wa_group_bool
+                                       {\msg_error:nn {witharrows}
+                                                      {Option~incompatible~with~group}}
+                                     \bool_set_true:N \l__wa_position_key_already_set_bool
+                                     \bool_set_false:N \l__wa_initial_r_bool
+                                     \bool_set_true:N  \l__wa_final_r_bool
+                                     \bool_set_false:N \l__wa_i_bool},
       rl       .groups:n          = {global,env,local,secondary},
       rl       .value_forbidden:n = true,
-      rl       .default:n         = true, 
-      rl       .code:n            = {\bool_if:NT \l_wa_position_key_already_set_bool
-                                       {\msg_error:nn {WithArrows} {Two~options~are~incompatible}}
-                                     \bool_if:NT \l_wa_group_bool
-                                       {\msg_error:nn {WithArrows} {Option~incompatible~with~group}}
-                                     \bool_set_true:N \l_wa_position_key_already_set_bool
-                                     \bool_set_true:N  \l_wa_initial_r_bool
-                                     \bool_set_false:N \l_wa_final_r_bool
-                                     \bool_set_false:N \l_wa_i_bool},
-      %
+      rl       .default:n         = true,
+      rl       .code:n            = {\bool_if:NT \l__wa_position_key_already_set_bool
+                                       {\msg_error:nn {witharrows}
+                                                      {Two~options~are~incompatible}}
+                                     \bool_if:NT \l__wa_group_bool
+                                       {\msg_error:nn {witharrows}
+                                                      {Option~incompatible~with~group}}
+                                     \bool_set_true:N \l__wa_position_key_already_set_bool
+                                     \bool_set_true:N  \l__wa_initial_r_bool
+                                     \bool_set_false:N \l__wa_final_r_bool
+                                     \bool_set_false:N \l__wa_i_bool},
       rr       .groups:n          = {global,env,local,secondary},
       rr       .value_forbidden:n = true,
-      rr       .default:n         = true, 
-      rr       .code:n            = {\bool_if:NT \l_wa_position_key_already_set_bool
-                                       {\msg_error:nn {WithArrows} {Two~options~are~incompatible}}
-                                     \bool_if:NT \l_wa_group_bool
-                                       {\msg_error:nn {WithArrows} {Option~incompatible~with~group}}
-                                     \bool_set_true:N \l_wa_position_key_already_set_bool
-                                     \bool_set_true:N  \l_wa_initial_r_bool
-                                     \bool_set_true:N  \l_wa_final_r_bool
-                                     \bool_set_false:N  \l_wa_i_bool},
-      %
+      rr       .default:n         = true,
+      rr       .code:n            = {\bool_if:NT \l__wa_position_key_already_set_bool
+                                       {\msg_error:nn {witharrows}
+                                                      {Two~options~are~incompatible}}
+                                     \bool_if:NT \l__wa_group_bool
+                                       {\msg_error:nn {witharrows}
+                                                      {Option~incompatible~with~group}}
+                                     \bool_set_true:N \l__wa_position_key_already_set_bool
+                                     \bool_set_true:N  \l__wa_initial_r_bool
+                                     \bool_set_true:N  \l__wa_final_r_bool
+                                     \bool_set_false:N  \l__wa_i_bool},
       i        .groups:n          = {global,env,local,secondary},
-      i        .code:n            = {\bool_if:NT \l_wa_position_key_already_set_bool
-                                       {\msg_error:nn {WithArrows} {Two~options~are~incompatible}}
-                                     \bool_if:NT \l_wa_group_bool
-                                       {\msg_error:nn {WithArrows} {Option~incompatible~with~group}}
-                                     \bool_set_true:N \l_wa_position_key_already_set_bool
-                                     \bool_set_true:N \l_wa_i_bool},
+      i        .code:n            = {\bool_if:NT \l__wa_position_key_already_set_bool
+                                       {\msg_error:nn {witharrows}
+                                                      {Two~options~are~incompatible}}
+                                     \bool_if:NT \l__wa_group_bool
+                                       {\msg_error:nn {witharrows}
+                                                      {Option~incompatible~with~group}}
+                                     \bool_set_true:N \l__wa_position_key_already_set_bool
+                                     \bool_set_true:N \l__wa_i_bool},
       i        .value_forbidden:n = true,
       i        .default:n         = true,
-      %
-      % indicate if all the arrows of an environment are grouped
-      % volontary not in "secondary" group : thus, if will be set first during the \keys_set_filter:nnn
-      group        .groups:n          = {global,env},   
-      group        .bool_set:N        = \l_wa_group_bool,
+      group        .groups:n          = {global,env},
+      group        .bool_set:N        = \l__wa_group_bool,
       group        .value_forbidden:n = true
 }
-
-
-
-
-
 \ProcessKeysOptions {WithArrows}
-
-
-% \WithArrowsOptions is the command of the WithArrows package to fix options at the document level
 \NewDocumentCommand \WithArrowsOptions {m}
-    {\bool_set_false:N \l_wa_position_key_already_set_bool
-     \keys_set_filter:nnn {WithArrows} {secondary} {#1}   % in order to raise an error if a key is unknown
+    {\bool_set_false:N \l__wa_position_key_already_set_bool
+     \keys_set_filter:nnn {WithArrows} {secondary} {#1}
      \keys_set_groups:nnn {WithArrows} {global} {#1}}
-
-
-
+\NewDocumentCommand \__wa_Arrow {O{} m O{}}
+         {\tl_if_eq:noF {WithArrows} {\@currenvir}
+                  {\msg_error:nn {witharrows} {Arrow~used~outside~{WithArrows}~environment}}
+          \int_gincr:N \g__wa_arrow_int
+          \int_zero_new:N \l__wa_jump_int
+          \int_set:Nn \l__wa_jump_int 1
+          \keys_set_groups:nnn {WithArrows} {jump} {#1,#3}
+          \prop_put:NnV \l_tmpa_prop {initial} \g__wa_line_int
+          \int_set:Nn \l_tmpa_int {\g__wa_line_int + \l__wa_jump_int}
+          \prop_put:NnV \l_tmpa_prop {final} \l_tmpa_int
+          \prop_put:Nnn \l_tmpa_prop {options} {#1,#3}
+          \prop_put:Nnn \l_tmpa_prop {label} {#2}
+          \prop_gclear_new:c
+                {g__wa_arrow_\l__wa_prefix_tl _\int_use:N\g__wa_arrow_int _prop}
+          \prop_gset_eq:cN
+                {g__wa_arrow_\l__wa_prefix_tl _\int_use:N\g__wa_arrow_int _prop}
+                \l_tmpa_prop
+          }
 \NewDocumentEnvironment {WithArrows} {O{}}
-          {\reverse_if:N \if_mode_math:
-                             \msg_error:nn {WithArrows} {WithArrows~used~outside~math~mode}
+         { \seq_gput_right:NV \g__wa_stack_counter_arrows_seq \g__wa_arrow_int
+           \int_gzero:N \g__wa_arrow_int
+           \seq_gput_right:NV \g__wa_stack_counter_lines_seq \g__wa_line_int
+           \int_gzero:N \g__wa_line_int
+           \seq_gput_right:NV \g__wa_stack_counter_lines_bis_seq \g__wa_line_bis_int
+           \int_gzero:N \g__wa_line_bis_int
+           \seq_gput_right:Nn \g__wa_position_in_the_tree_seq 1
+           \seq_set_eq:NN \l_tmpa_seq \g__wa_position_in_the_tree_seq
+           \seq_pop_right:NN \l_tmpa_seq \l_tmpa_tl
+           \tl_clear_new:N \l__wa_prefix_tl
+           \tl_set:Nx \l__wa_prefix_tl {\seq_use:Nnnn \l_tmpa_seq {-} {-} {-}}
+
+           \reverse_if:N \if_mode_math:
+                             \msg_error:nn {witharrows} {{WithArrows}~used~outside~math~mode}
                          \fi
-           \savenotes % to extract the footnotes of the environment {WithArrows}
-           \m@th                
-           \def\\{\cr}
-           %
-           \int_gzero_new:N \g_wa_line_int  % to count the lines in the \halign 
-           %
-           % to count the arrows created in the environment
-           \int_gzero_new:N \g_wa_arrow_int 
-           %
-           % these 3 counters will be used later as variables
-           \int_zero_new:N \l_initial_int
-           \int_zero_new:N \l_final_int
-           \int_zero_new:N \l_arrow_int
-           % 
-           \bool_set_false:N \l_wa_position_key_already_set_bool
-           \keys_set_filter:nnn {WithArrows} {secondary} {#1} % in order to raise an error if a key is unknown
+           \savenotes
+           \cs_set_eq:NN \\ \__wa_cr:
+           \mathsurround = \c_zero_dim
+           \int_zero_new:N \l__wa_initial_int
+           \int_zero_new:N \l__wa_final_int
+           \int_zero_new:N \l__wa_arrow_int
+           \bool_set_false:N \l__wa_position_key_already_set_bool
+           \skip_zero:N \l__wa_interline_skip
+           \keys_set_filter:nnn {WithArrows} {secondary} {#1}
            \keys_set_groups:nnn {WithArrows} {env} {#1}
-           %
-           \cs_set:cpn \l_wa_CommandName_tl {\wa_Arrow} % new name for \Arrow command in {WithArrows} environments
-           %
-           \int_case:nnF \l_wa_pos_int % is fixed via the options t, c or b
+           \cs_set_eq:cN \l__wa_CommandName_tl \__wa_Arrow
+           \int_case:nn \l__wa_pos_int
                    {0 {\vtop}
                     1 {\vcenter}
                     2 {\vbox}}
-                   {\msg_error:nn {WithArrows} {Bad~value~for~option~pos}}
            \bgroup
-           \openup\jot
+           \spread@equation
            \ialign\bgroup
-           \int_gincr:N \g_wa_line_int % will be used for the names of the 2 nodes of the line
+           \int_gincr:N \g__wa_line_int
            \strut\hfil
-           $\bool_if:NT \l_wa_displaystyle_bool \displaystyle {##}$
-           & 
-           $\bool_if:NT \l_wa_displaystyle_bool \displaystyle {{}##}$
-           %
-           % we create a first node (the "left node" of the line)
-           \tikz[remember~picture] 
-                  \node [wa_node_style] (wa-\int_use:N\g_wa_line_int-l) {} ;
+           $\bool_if:NT \l__wa_displaystyle_bool \displaystyle {##}$
+           &
+           \int_gincr:N \g__wa_line_bis_int
+           $\bool_if:NT \l__wa_displaystyle_bool \displaystyle {{}##}$
+           \tikz[remember~picture]
+                  \node [__wa_node_style]
+                  (wa-\tl_use:N\l__wa_prefix_tl-\int_use:N\g__wa_line_int-l) {} ;
            \hfil
-           % we create a second node (the "right node" of the line)
-           \tikz[remember~picture] 
-                  \node [wa_node_style] (wa-\int_use:N\g_wa_line_int-r) {} ;
+           \tikz[remember~picture,label~position=right]
+                  \node [__wa_node_style]
+                  (wa-\tl_use:N\l__wa_prefix_tl-\int_use:N\g__wa_line_int-r) {} ;
+           \bool_if:NT \l__wa_shownodenames_bool
+                {\hbox_overlap_right:n {\small wa-\tl_use:N\l__wa_prefix_tl
+                                                 -\int_use:N\g__wa_line_int}}
+           && \bool_if:NF \l__wa_MoreColumns_bool
+                {\msg_error:nn {witharrows} {Third~column~in~a~{WithArrows}~environment}}
+           $\bool_if:NT \l__wa_displaystyle_bool \displaystyle {##}$
            \cr
           }
-          {\crcr % 
-           \egroup% end of halign
-           \egroup% end of vtop (or \vcenter or \vbox)
-           %
-           \int_compare:nNnT \g_wa_arrow_int > 0   % If there is really arrows...
-                    \wa_draw_arrows:               % ...we draw these arrows.
+          {\crcr
+           \egroup
+           \egroup
+           \int_compare:nNnT \g__wa_line_bis_int < \g__wa_line_int
+                  {\msg_error:nn {witharrows} {All~lines~must~have~an~ampersand}}
+            \int_compare:nNnT \g__wa_arrow_int > 0
+                    \__wa_draw_arrows:
            \spewnotes
+           \seq_gpop_right:NN \g__wa_position_in_the_tree_seq \l_tmpa_tl
+           \seq_gpop_right:NN \g__wa_position_in_the_tree_seq \l_tmpa_tl
+           \seq_gput_right:Nx \g__wa_position_in_the_tree_seq {\int_eval:n {\l_tmpa_tl + 1}}
+           \int_compare:nNnT {\seq_count:N \g__wa_position_in_the_tree_seq} = 1
+                      {\int_gincr:N \g__wa_last_env_int}
+           \seq_gpop_right:NN \g__wa_stack_counter_arrows_seq {\l_tmpa_tl}
+           \int_gset:Nn \g__wa_arrow_int {\l_tmpa_tl}
+           \seq_gpop_right:NN \g__wa_stack_counter_lines_seq \l_tmpa_tl
+           \int_gset:Nn \g__wa_line_int {\l_tmpa_tl}
+           \seq_gpop_right:NN \g__wa_stack_counter_lines_bis_seq \l_tmpa_tl
+           \int_gset:Nn \g__wa_line_bis_int {\l_tmpa_tl}
            }
-
-
-
-% le following code is necessary because we whill have to expand un argument exactly 3 times
+\cs_set_protected:Nn \__wa_cr:
+      {\scan_stop:
+       \group_align_safe_begin:
+       \peek_meaning_remove:NTF * \__wa_cr_i: \__wa_cr_i:}
+\cs_set_protected:Nn \__wa_cr_i:
+      {\peek_meaning:NTF [ {\__wa_cr_ii:} {\__wa_cr_ii:[\c_zero_dim]} }
+\cs_new_protected:Npn \__wa_cr_ii:[#1]
+      {\group_align_safe_end:
+       \cr\noalign{\skip_vertical:n {#1 + \l__wa_interline_skip}
+       \scan_stop:}}
 \cs_generate_variant:Nn \keys_set_groups:nnn {nno}
-\cs_new:Nn \keys_set_groups_WithArrows_local: {\keys_set_groups:nno {WithArrows} {local}}
-
+\cs_new_protected:Nn \keys_set_groups_WithArrows_local:
+                     {\keys_set_groups:nno {WithArrows} {local}}
 \cs_generate_variant:Nn \keys_set_filter:nnn {nno}
-\cs_new:Nn \keys_set_filter_WithArrows_secondary: {\keys_set_filter:nno {WithArrows} {secondary}}
-
-\cs_new:Nn \wa_draw_arrows:
-  {%
-   % if the option "group" is used in the current environment
-   \bool_if:NT \l_wa_group_bool
-        \wa_x_computation_for_option_group:   % will compute \g_wa_x_dim which is the abscissa of all the arrows 
-   %
-   % loop over the arrows created in the environment : the arrows will be drawn
-   \int_set:Nn \l_arrow_int 1
-   \int_until_do:nNnn \l_arrow_int > \g_wa_arrow_int   % g_wa_arrow_int is the total number of arrows
+\cs_new_protected:Nn \keys_set_filter_WithArrows_secondary:
+           {\keys_set_filter:nno {WithArrows} {secondary}}
+\cs_new_protected:Nn \__wa_draw_arrows:
+  {
+   \bool_if:NT \l__wa_group_bool
+        \__wa_x_computation_for_option_group:
+   \int_set:Nn \l__wa_arrow_int 1
+   \int_until_do:nNnn \l__wa_arrow_int > \g__wa_arrow_int
      {
-      % \l_initial_int is the line number from which the arrow starts
-      \int_set:Nn \l_initial_int {\int_use:c {wa_initial\int_use:N\l_arrow_int}}
-      %
-      % \l_final_int is the line number to which the arrow ends
-      \int_set:Nn \l_final_int {\int_use:c {wa_final\int_use:N\l_arrow_int}}
-      %
-      \int_compare:nNnT \l_final_int > \g_wa_line_int
-             {\msg_error:nn {WithArrows} {Too~few~lines~for~an~arrow}}
-      %
-      \group_begin: % for the options given in \Arrow[...] ("local level" of the options)
+      \prop_get:cnN {g__wa_arrow_\l__wa_prefix_tl _\int_use:N\l__wa_arrow_int _prop}
+                    {initial} \l_tmpa_tl
+      \int_set:Nn \l__wa_initial_int {\l_tmpa_tl}
+      \prop_get:cnN {g__wa_arrow_\l__wa_prefix_tl _\int_use:N\l__wa_arrow_int _prop}
+                    {final} \l_tmpa_tl
+      \int_set:Nn \l__wa_final_int {\l_tmpa_tl}
+      \int_compare:nNnT \l__wa_final_int > \g__wa_line_int
+             {\msg_error:nn {witharrows} {Too~few~lines~for~an~arrow}}
+           \group_begin:
            \keys_define:nn {WithArrows} {group .undefine:}
-           \bool_set_false:N \l_wa_position_key_already_set_bool
-           % the third argument de \keys_set_groups:nnn must be expanded exactly three times
-           % a x-expansion is not possible because there can be tokens like \bfseries in the option "font"
-           \exp_args:NNo \exp_args:No \keys_set_filter_WithArrows_secondary: {\use:c {wa_options\int_use:N\l_arrow_int}}
-           \exp_args:NNo \exp_args:No \keys_set_groups_WithArrows_local: {\use:c {wa_options\int_use:N\l_arrow_int}}
-           %
-           % In case of option "i", we have to compute the abscissa of the arrow (which is vertical).
-           \bool_if:NT \l_wa_i_bool
-               \wa_x_computation_for_option_i: % the abscissa is computed in \g_wa_x_dim
-           %
-           % \l_initial_tl contains the name of the Tikz node from which the arrow starts (in normal cases...
-           % because with option "group" or option "i", the point will perhaps have an other x-value --- but always the
-           % same y-value). 
-           \tl_set:Nx \l_initial_tl {wa-\int_use:N\l_initial_int-\bool_if:NTF\l_wa_initial_r_bool rl} 
-           %
-           % \l_final_tl contains the name of the Tikz node to which the arrow ends (in normal cases : with option
-           % "group" or option "i", the point will perhaps have an other x-value but always the same y-value)
-           \tl_set:Nx \l_final_tl {wa-\int_use:N\l_final_int-\bool_if:NTF\l_wa_final_r_bool rl . north}
-           % ". north" because we want a small gap between two consecutive arrows
-           % 
+           \bool_set_false:N \l__wa_position_key_already_set_bool
+           \prop_get:cnN {g__wa_arrow_\l__wa_prefix_tl
+                             _\int_use:N\l__wa_arrow_int _prop} {options} \l_tmpa_tl
+           \exp_args:NNo \exp_args:No \keys_set_filter_WithArrows_secondary: {\l_tmpa_tl}
+           \exp_args:NNo \exp_args:No \keys_set_groups_WithArrows_local: {\l_tmpa_tl}
+           \bool_if:NT \l__wa_i_bool
+               \__wa_x_computation_for_option_i:
+           \tl_set:Nx \l__wa_initial_tl
+                   {wa-\tl_use:N\l__wa_prefix_tl-\int_use:N\l__wa_initial_int-
+                            \bool_if:NTF\l__wa_initial_r_bool rl}
+           \tl_set:Nx \l__wa_final_tl
+                   {wa-\tl_use:N\l__wa_prefix_tl-\int_use:N\l__wa_final_int-
+                            \bool_if:NTF\l__wa_final_r_bool rl . north}
            \begin{tikzpicture}[remember~picture,
                                overlay,
                                align=left,
@@ -345,161 +332,106 @@
                                ->,
                                looseness=1,
                                bend~left=45]
-           \draw \exp_after:wN [\l_wa_options_tikz_tl]
-                 % \p1 and \p2 are the two ends of the arrow (in fact, not exactly in case of options "group" or "i")
-                 let \p1 = (\tl_use:N \l_initial_tl),
-                     \p2 = (\tl_use:N \l_final_tl) in 
-                   (\bool_if:nTF {\l_wa_group_bool || \l_wa_i_bool}
-                     {\dim_use:N \g_wa_x_dim + \dim_use:N \l_wa_xoffset_dim, \y1}
-                     {\x1 + \dim_use:N \l_wa_xoffset_dim, \y1} )
-                   to node (wa-a-\int_use:N\l_arrow_int) % in fact, this name will not be used by WithArrows
-                           {\tl_use:c {wa_label\int_use:N\l_arrow_int}}
-                   (\bool_if:nTF {\l_wa_group_bool || \l_wa_i_bool}
-                     {\dim_use:N \g_wa_x_dim + \dim_use:N \l_wa_xoffset_dim, \y2}
-                     {\x2 + \dim_use:N \l_wa_xoffset_dim, \y2} ) ; 
+           \prop_get:cnN {g__wa_arrow_\l__wa_prefix_tl _\int_use:N\l__wa_arrow_int _prop}
+                         {label} \l_tmpa_tl
+           \draw \exp_after:wN [\l__wa_options_tikz_tl]
+                 let \p1 = (\tl_use:N \l__wa_initial_tl),
+                     \p2 = (\tl_use:N \l__wa_final_tl) in
+                   (\bool_if:nTF {\l__wa_group_bool || \l__wa_i_bool}
+                     {\dim_use:N \g__wa_x_dim + \dim_use:N \l__wa_xoffset_dim, \y1}
+                     {\x1 + \dim_use:N \l__wa_xoffset_dim, \y1} )
+                   to node [node~contents = {\tl_use:N \l_tmpa_tl}] {}
+                   (\bool_if:nTF {\l__wa_group_bool || \l__wa_i_bool}
+                     {\dim_use:N \g__wa_x_dim + \dim_use:N \l__wa_xoffset_dim, \y2}
+                     {\x2 + \dim_use:N \l__wa_xoffset_dim, \y2} ) ;
            \end{tikzpicture}
-       \group_end: % for the options given to \Arrow[...] ("local level" of the options)
-       \int_incr:N \l_arrow_int
-      } % end of the loop over the arrows : all arrows are drawn
+       \group_end:
+       \int_incr:N \l__wa_arrow_int
+      }
      }
-
-
-% We want to compute the x-value for the current environment which has option "group" (and therefore all arrows are
-% vertical at the same abscissa). This value will be computed in \g_wa_x_dim (which is global for technical reasons :
-% we have to do assignments in a \tikz command).
-\cs_new:Nn \wa_x_computation_for_option_group:
-  {\dim_gzero_new:N \g_wa_x_dim
-   %
-   % first, we calculate the initial value for \g_wa_x_dim
-   % in this \tikz command, nothing is drawn : we only want to read the abscissa of a Tikz node
-   \tikz[remember~picture]
-      \path let \p1 = (wa-\int_use:c{wa_initial1}-l)      % "let" is given by the Tikz library "calc"
-            in \pgfextra {\dim_gset:Nn \g_wa_x_dim {\x1}} ;  % a global assignment is necessary because of \tikz
-   %
-   % Then, we loop to determine the maximal length of all the lines concerned by the arrows of the environment.
-   \int_set:Nn \l_arrow_int 1
-   \int_until_do:nNnn \l_arrow_int > \g_wa_arrow_int   % g_wa_arrow_int is the total number of arrows
-      { % \l_initial_int is the line number from which the arrow starts
-        \int_set:Nn \l_initial_int {\int_use:c {wa_initial\int_use:N\l_arrow_int}}
-        %
-        % \l_final_int is the line number to which the arrow ends
-        \int_set:Nn \l_final_int {\int_use:c {wa_final\int_use:N\l_arrow_int}}
-        %
-        \wa_x_computation_analyze_lines_between: %... between lines \l_initial_int and \l_final_int
-        %
-        \int_incr:N \l_arrow_int
-      } % end of the loop over the arrows of the environment
-   }   
-
-
-% We want to compute the x-value for the current arrow which has option "i" (and therefore is vertical).
-% This value will be computed in \g_wa_x_dim (which is global for technical reasons : we have to do assignments in
-% a \tikz command). 
-\cs_new:Nn \wa_x_computation_for_option_i:
-  {\dim_gzero_new:N \g_wa_x_dim
-   % First, we calculate the initial value for \g_wa_x_dim.
-   % In the next \tikz command, nothing is drawn : we only want to read a abscissa of a Tikz node.
+\cs_new_protected:Nn \__wa_x_computation_for_option_i:
+  {\dim_gzero_new:N \g__wa_x_dim
    \tikz[remember~picture]
-      \path let \p1 = (wa-\int_use:N\l_initial_int-l) % "let" is given by the Tikz library "calc"
-            in \pgfextra {\dim_gset:Nn \g_wa_x_dim {\x1}} ;  % a global assignment is necessary because of \tikz
-   %
-   \wa_x_computation_analyze_lines_between:  %... between lines \l_initial_int and \l_final_int
+      \path let \p1 = (wa-\tl_use:N\l__wa_prefix_tl-\int_use:N\l__wa_initial_int-l)
+            in \pgfextra {\dim_gset:Nn \g__wa_x_dim {\x1}} ;
+   \__wa_x_computation_analyze_lines_between:
    }
-
-
-
-        
-% We analyse lines between \l_initial_int and \l_final_int in order to modify \g_wa_x_dim in consequence.
-% More precisely, we will increase \g_wa_x_dim if we find a line longer than the current value of \g_wa_x_dim.
-\cs_new:Nn \wa_x_computation_analyze_lines_between:
-    {\int_compare:nNnT \l_final_int > \g_wa_line_int
-             {\msg_error:nn {WithArrows} {Too~few~lines~for~an~arrow}}
-     %
-     % \l_tmpa_int will be the index of the loop
-     \int_set:Nn \l_tmpa_int \l_initial_int
-     \int_until_do:nNnn \l_tmpa_int > \l_final_int
-         {% in the next \tikz command, nothing is drawn : we only want to read the abscissa of a Tikz node
-          \tikz[remember~picture]
-             \path let \p1 = (wa-\int_use:N\l_tmpa_int-l) 
-                   in \pgfextra {\dim_gset:Nn \g_wa_x_dim {\dim_max:nn \g_wa_x_dim {\x1}}} ; % \gset because of \tikz
+\cs_new_protected:Nn \__wa_x_computation_analyze_lines_between:
+    {\int_compare:nNnT \l__wa_final_int > \g__wa_line_int
+             {\msg_error:nn {witharrows} {Too~few~lines~for~an~arrow}}
+     \int_set:Nn \l_tmpa_int \l__wa_initial_int
+     \int_until_do:nNnn \l_tmpa_int > \l__wa_final_int
+         {\tikz[remember~picture]
+             \path let \p1 = (wa-\tl_use:N\l__wa_prefix_tl-\int_use:N\l_tmpa_int-l)
+                   in \pgfextra {\dim_gset:Nn \g__wa_x_dim {\dim_max:nn \g__wa_x_dim {\x1}}} ;
           \int_incr:N \l_tmpa_int
-         } % loop on the lines between \l_initial_int et \l_final_int
-    }   
-
-
-
+         }
+    }
+\cs_new_protected:Nn \__wa_x_computation_for_option_group:
+  {\dim_gzero_new:N \g__wa_x_dim
+   \prop_get:cnN {g__wa_arrow_\l__wa_prefix_tl _1_prop} {initial} \l_tmpa_tl
+   \tikz[remember~picture]
+      \path let \p1 = (wa-\tl_use:N\l__wa_prefix_tl-\tl_use:N\l_tmpa_tl-l)
+            in \pgfextra {\dim_gset:Nn \g__wa_x_dim {\x1}} ;
+   \int_set:Nn \l__wa_arrow_int 1
+   \int_until_do:nNnn \l__wa_arrow_int > \g__wa_arrow_int
+      {
+        \prop_get:cnN {g__wa_arrow_\l__wa_prefix_tl _\int_use:N\l__wa_arrow_int _prop}
+                      {initial} \l_tmpa_tl
+        \int_set:Nn \l__wa_initial_int {\l_tmpa_tl}
+        \prop_get:cnN {g__wa_arrow_\l__wa_prefix_tl _\int_use:N\l__wa_arrow_int _prop}
+                      {final} \l_tmpa_tl
+        \int_set:Nn \l__wa_final_int {\l_tmpa_tl}
+        \__wa_x_computation_analyze_lines_between:
+        \int_incr:N \l__wa_arrow_int
+      }
+   }
 \cs_generate_variant:Nn \int_compare:nNnT {cNnT}
-
-\cs_generate_variant:Nn \tl_if_eq:nnF {onF}
-
-
-% The next command has a strange name, but, in fact, usually, we will have \let\Arrow\wa_Arrow ;
-% The user can use the CommandName option if he wants an other name for the command called \Arrow by default.
-% It's useful if the user already has a command named "\Arrow" he still wants to use.
-\NewDocumentCommand \wa_Arrow {O{} m O{}}
-         {\tl_if_eq:onF {\@currenvir} {WithArrows}
-                  {\msg_fatal:nn {WithArrows} {Arrow~used~outside~{WithArrows}~environment}}
-          %
-          % \g_wa_arrow_int counts the arrows in the environment
-          \int_gincr:N \g_wa_arrow_int
-          %
-          % we decide to extract immediatly the key "jump" in ordre to compute the end line ;
-          \int_zero_new:N \l_jump_int
-          \int_set:Nn \l_jump_int 1
-          \keys_set_groups:nnn {WithArrows} {jump} {#1,#3} % "jump" is the only key of the group "jump"
-          % 
-          % to stock the informations of the considered arrow (in four variables) ;
-          % these informations will be used when the arrow will be really drawn
-          \int_gzero_new:c {wa_initial\int_use:N\g_wa_arrow_int}
-          \int_gset_eq:cN  {wa_initial\int_use:N\g_wa_arrow_int} \g_wa_line_int
-          %
-          \int_gzero_new:c {wa_final\int_use:N\g_wa_arrow_int}
-          \int_gset:cn     {wa_final\int_use:N\g_wa_arrow_int} {\g_wa_line_int + \l_jump_int}
-          %
-          \tl_gclear_new:c {wa_options\int_use:N\g_wa_arrow_int}
-          \tl_gset:cn      {wa_options\int_use:N\g_wa_arrow_int} {#1,#3}
-          %
-          \tl_gclear_new:c {wa_label\int_use:N\g_wa_arrow_int}
-          \tl_gset:cn      {wa_label\int_use:N\g_wa_arrow_int} {#2}
-          %
-          }
-
-
-
-\msg_new:nnn {WithArrows}
+\cs_generate_variant:Nn \tl_if_eq:nnF {noF}
+\bigskip
+\NewDocumentCommand \WithArrowsLastEnv {}
+     {\int_use:N \g__wa_last_env_int}
+\msg_new:nnn {witharrows}
+             {Third~column~in~a~{WithArrows}~environment}
+             {By~default,~a~\{WithArrows\}~environment~can~only~have~two~columns.~
+              Maybe~you~have~forgotten~a~newline~symbol.~If~you~really~want~
+              more~than~two~columns,~you~should~use~the~option~"MoreColumns"~at~
+              a~global~level~or~for~an~environment.~However,~you~can~go~one~for~this~time.}
+\msg_new:nnn {witharrows}
              {Arrow~used~outside~{WithArrows}~environment}
-             {Arrow~command~should~be~used~only~directly~in~\{WithArrows\}~environment\\
-              and~not~in~a~subenvironment.}
-
-\msg_new:nnn {WithArrows}
+             {The~command~\string\Arrow\space~should~be~used~only~directly~
+              in~\{WithArrows\}~environment~and~not~in~a~subenvironment.~However,~you~
+              can~go~on.}
+\msg_new:nnn {witharrows}
              {The~option~"jump"~must~be~non~negative}
-             {You~can't~use~a~stricly~negative~value~for~the~option~"jump"~of~command~Arrow\\
-              You~can~create~an~arrow~going~backwards~with~the~option~"<-"~of~Tikz.}
-
-\msg_new:nnn {WithArrows}          
+             {You~can't~use~a~strictly~negative~value~for~the~option~"jump"~of~command~
+              \string\Arrow.~ You~can~create~an~arrow~going~backwards~with~
+              the~option~"<-"~of~Tikz.}
+\msg_new:nnn {witharrows}
              {Too~few~lines~for~an~arrow}
-             {There~is~at~least~an~arrow~that~can't~be~drawn~because~it~arrives~after~the\\
+             {There~is~at~least~an~arrow~that~can't~be~drawn~because~it~arrives~after~the~
               last~line~of~the~environment.}
-
-\msg_new:nnn {WithArrows}
-             {Bad~value~for~option~pos}
-             {The~option~"pos"~of~the~environment~\{WithArrows\}~must~be~equal~to\\        
-              0,~1,~or~2.}
-
-\msg_new:nnn {WithArrows}
-             {WithArrows~used~outside~math~mode}
-             {The~environment~WithArrows~must~be~used~only~in~math~mode.}
-
-\msg_new:nnn {WithArrows}
+\msg_new:nnn {witharrows}
+             {{WithArrows}~used~outside~math~mode}
+             {The~environment~\{WithArrows\}~should~be~used~only~in~math~mode.~
+              Nevertheless,~you~can~go~on.}
+\msg_new:nnn {witharrows}
              {Option~incompatible~with~group}
-             {You~try~to~use~the~option~"\tl_use:N\l_keys_key_tl"~while~you~are~using~the~option~"group".\\
-              It's~incompatible.~You~can~go~on~ignoring~this~option~"\tl_use:N\l_keys_key_tl"~and~"group"~will~be~used.}
-
-
-\msg_new:nnn {WithArrows}
+             {You~try~to~use~the~option~"\tl_use:N\l_keys_key_tl"~while~
+              you~are~using~the~option~"group".~It's~incompatible.~You~can~go~on~ignoring~
+              this~option~"\tl_use:N\l_keys_key_tl"~and~"group"~will~be~used.}
+\msg_new:nnn {witharrows}
              {Two~options~are~incompatible}
-             {You~try~to~use~the~option~"\tl_use:N\l_keys_key_tl"~but~this~option~is~incompatible\\
-              with~an~option~previously~set.~If~you~go~on,~it~will~overwrite~the~previous~option.}
-
-
-\endinput
\ No newline at end of file
+             {You~try~to~use~the~option~"\tl_use:N\l_keys_key_tl"~but~
+             this~option~is~incompatible~with~an~option~previously~set.~
+             If~you~go~on,~I~will~overwrite~the~previous~option.}
+\msg_new:nnnn {witharrows}
+              {All~lines~must~have~an~ampersand}
+              {All~lines~of~an~environment~\{WithArrows\}~must~have~an~second~column~
+               (because~the~nodes~are~created~in~the~second~column).~You~can~go~on~but~maybe~
+               you~will~have~an~pgf~error~for~an~undefined~shape.}
+              {The~ampersand~can~be~implicit~
+               (e.g.~if~you~use~\string\MoveEqLeft\space~of~mathtools).}
+\endinput
+%%
+%% End of file `witharrows.sty'.