chemnum 0.6 (20jan13)

git-svn-id: svn://tug.org/texlive/trunk@28883 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 653 insertions, 655 deletions

diff --git a/Master/texmf-dist/tex/latex/chemnum/chemnum.sty b/Master/texmf-dist/tex/latex/chemnum/chemnum.sty
index 5d3525cddd2..83885ea3f14 100644
--- a/Master/texmf-dist/tex/latex/chemnum/chemnum.sty
+++ b/Master/texmf-dist/tex/latex/chemnum/chemnum.sty
@@ -8,7 +8,7 @@
 % - If you have any ideas, questions, suggestions or bugs to report, please
 % - feel free to contact me.
 % -----------------------------------------------------------------------------
-% - Copyright 2011-2012 Clemens Niederberger
+% - Copyright 2011-2013 Clemens Niederberger
 % -
 % - This work may be distributed and/or modified under the
 % - conditions of the LaTeX Project Public License, either version 1.3
@@ -32,8 +32,8 @@
 
 \ProvidesExplPackage
   {chemnum}
-  {2012/12/29}
-  {0.5f}
+  {2013/01/20}
+  {0.6}
   {a comprehensive approach for the numbering of chemical compounds}
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -93,10 +93,10 @@
   }
 
 % textgreek support and package options:
-\bool_new:N \l_chemnum_textgreek_bool
-\bool_set_false:N \l_chemnum_textgreek_bool
+\bool_new:N \l__chemnum_textgreek_bool
+\bool_set_false:N \l__chemnum_textgreek_bool
 
-\cs_new_nopar:Npn \chemnum_load_textgreek:n #1
+\cs_new_nopar:Npn \__chemnum_load_textgreek:n #1
   {
     \AtEndPreamble
       {
@@ -105,155 +105,155 @@
             \@ifpackageloaded { textgreek }
               { \msg_warning:nnx { chemnum } { textgreek-loaded } { #1 } }
               { \RequirePackage [ #1 ] { textgreek } }
-            \bool_set_true:N \l_chemnum_textgreek_bool
+            \bool_set_true:N \l__chemnum_textgreek_bool
           }
           {
             \msg_warning:nnx { chemnum } { support-missing } { textgreek }
-            \bool_set_false:N \l_chemnum_textgreek_bool
+            \bool_set_false:N \l__chemnum_textgreek_bool
           }
       }
   }
 
-\cs_new:Npn \chemnum_package_options:n #1
+\cs_new:Npn \__chemnum_package_options:n #1
   { \keys_set:nn { chemnum / package } { #1 } }
 
 \keys_define:nn { chemnum / package } {
   textgreek .choice: ,
-  textgreek / artemisia .code:n     = \chemnum_load_textgreek:n { #1 } ,
-  textgreek / cbgreek   .code:n     = \chemnum_load_textgreek:n { #1 } ,
-  textgreek / euler     .code:n     = \chemnum_load_textgreek:n { #1 } ,
+  textgreek / artemisia .code:n     = \__chemnum_load_textgreek:n { #1 } ,
+  textgreek / cbgreek   .code:n     = \__chemnum_load_textgreek:n { #1 } ,
+  textgreek / euler     .code:n     = \__chemnum_load_textgreek:n { #1 } ,
   textgreek / false     .code:n     =
-    { \bool_set_false:N \l_chemnum_textgreek_bool } ,
+    { \bool_set_false:N \l__chemnum_textgreek_bool } ,
   textgreek             .default:n  = cbgreek
 }
 
 \ProcessKeysOptions { chemnum / package }
 
 \AtBeginDocument{
-\bool_if:NTF \l_chemnum_textgreek_bool
+\bool_if:NTF \l__chemnum_textgreek_bool
   {
-    \cs_new_eq:NN \chemnum_alpha:   \textalpha
-    \cs_new_eq:NN \chemnum_beta:    \textbeta
-    \cs_new_eq:NN \chemnum_gamma:   \textgamma
-    \cs_new_eq:NN \chemnum_delta:   \textdelta
-    \cs_new_eq:NN \chemnum_epsilon: \textepsilon
-    \cs_new_eq:NN \chemnum_zeta:    \textzeta
-    \cs_new_eq:NN \chemnum_eta:     \texteta
-    \cs_new_eq:NN \chemnum_theta:   \texttheta
-    \cs_new_eq:NN \chemnum_iota:    \textiota
-    \cs_new_eq:NN \chemnum_kappa:   \textkappa
-    \cs_new_eq:NN \chemnum_lambda:  \textlambda
-    \cs_new_eq:NN \chemnum_mu:      \textmugreek
-    \cs_new_eq:NN \chemnum_nu:      \textnu
-    \cs_new_eq:NN \chemnum_xi:      \textxi
-    \cs_new_eq:NN \chemnum_omikron: \textomikron
-    \cs_new_eq:NN \chemnum_pi:      \textpi
-    \cs_new_eq:NN \chemnum_rho:     \textrho
-    \cs_new_eq:NN \chemnum_sigma:   \textsigma
-    \cs_new_eq:NN \chemnum_tau:     \texttau
-    \cs_new_eq:NN \chemnum_upsilon: \textupsilon
-    \cs_new_eq:NN \chemnum_phi:     \textphi
-    \cs_new_eq:NN \chemnum_chi:     \textchi
-    \cs_new_eq:NN \chemnum_psi:     \textpsi
-    \cs_new_eq:NN \chemnum_omega:   \textomega
-    \cs_new_eq:NN \chemnum_Alpha:   \textAlpha
-    \cs_new_eq:NN \chemnum_Beta:    \textBeta
-    \cs_new_eq:NN \chemnum_Gamma:   \textGamma
-    \cs_new_eq:NN \chemnum_Delta:   \textDelta
-    \cs_new_eq:NN \chemnum_Epsilon: \textEpsilon
-    \cs_new_eq:NN \chemnum_Zeta:    \textZeta
-    \cs_new_eq:NN \chemnum_Eta:     \textEta
-    \cs_new_eq:NN \chemnum_Theta:   \textTheta
-    \cs_new_eq:NN \chemnum_Iota:    \textIota
-    \cs_new_eq:NN \chemnum_Kappa:   \textKappa
-    \cs_new_eq:NN \chemnum_Lambda:  \textLambda
-    \cs_new_eq:NN \chemnum_Mu:      \textMugreek
-    \cs_new_eq:NN \chemnum_Nu:      \textNu
-    \cs_new_eq:NN \chemnum_Xi:      \textXi
-    \cs_new_eq:NN \chemnum_Omikron: \textOmikron
-    \cs_new_eq:NN \chemnum_Pi:      \textPi
-    \cs_new_eq:NN \chemnum_Rho:     \textRho
-    \cs_new_eq:NN \chemnum_Sigma:   \textSigma
-    \cs_new_eq:NN \chemnum_Tau:     \textTau
-    \cs_new_eq:NN \chemnum_Upsilon: \textUpsilon
-    \cs_new_eq:NN \chemnum_Phi:     \textPhi
-    \cs_new_eq:NN \chemnum_Chi:     \textChi
-    \cs_new_eq:NN \chemnum_Psi:     \textPsi
-    \cs_new_eq:NN \chemnum_Omega:   \textOmega
+    \cs_new_eq:NN \__chemnum_alpha:   \textalpha
+    \cs_new_eq:NN \__chemnum_beta:    \textbeta
+    \cs_new_eq:NN \__chemnum_gamma:   \textgamma
+    \cs_new_eq:NN \__chemnum_delta:   \textdelta
+    \cs_new_eq:NN \__chemnum_epsilon: \textepsilon
+    \cs_new_eq:NN \__chemnum_zeta:    \textzeta
+    \cs_new_eq:NN \__chemnum_eta:     \texteta
+    \cs_new_eq:NN \__chemnum_theta:   \texttheta
+    \cs_new_eq:NN \__chemnum_iota:    \textiota
+    \cs_new_eq:NN \__chemnum_kappa:   \textkappa
+    \cs_new_eq:NN \__chemnum_lambda:  \textlambda
+    \cs_new_eq:NN \__chemnum_mu:      \textmugreek
+    \cs_new_eq:NN \__chemnum_nu:      \textnu
+    \cs_new_eq:NN \__chemnum_xi:      \textxi
+    \cs_new_eq:NN \__chemnum_omikron: \textomikron
+    \cs_new_eq:NN \__chemnum_pi:      \textpi
+    \cs_new_eq:NN \__chemnum_rho:     \textrho
+    \cs_new_eq:NN \__chemnum_sigma:   \textsigma
+    \cs_new_eq:NN \__chemnum_tau:     \texttau
+    \cs_new_eq:NN \__chemnum_upsilon: \textupsilon
+    \cs_new_eq:NN \__chemnum_phi:     \textphi
+    \cs_new_eq:NN \__chemnum_chi:     \textchi
+    \cs_new_eq:NN \__chemnum_psi:     \textpsi
+    \cs_new_eq:NN \__chemnum_omega:   \textomega
+    \cs_new_eq:NN \__chemnum_Alpha:   \textAlpha
+    \cs_new_eq:NN \__chemnum_Beta:    \textBeta
+    \cs_new_eq:NN \__chemnum_Gamma:   \textGamma
+    \cs_new_eq:NN \__chemnum_Delta:   \textDelta
+    \cs_new_eq:NN \__chemnum_Epsilon: \textEpsilon
+    \cs_new_eq:NN \__chemnum_Zeta:    \textZeta
+    \cs_new_eq:NN \__chemnum_Eta:     \textEta
+    \cs_new_eq:NN \__chemnum_Theta:   \textTheta
+    \cs_new_eq:NN \__chemnum_Iota:    \textIota
+    \cs_new_eq:NN \__chemnum_Kappa:   \textKappa
+    \cs_new_eq:NN \__chemnum_Lambda:  \textLambda
+    \cs_new_eq:NN \__chemnum_Mu:      \textMugreek
+    \cs_new_eq:NN \__chemnum_Nu:      \textNu
+    \cs_new_eq:NN \__chemnum_Xi:      \textXi
+    \cs_new_eq:NN \__chemnum_Omikron: \textOmikron
+    \cs_new_eq:NN \__chemnum_Pi:      \textPi
+    \cs_new_eq:NN \__chemnum_Rho:     \textRho
+    \cs_new_eq:NN \__chemnum_Sigma:   \textSigma
+    \cs_new_eq:NN \__chemnum_Tau:     \textTau
+    \cs_new_eq:NN \__chemnum_Upsilon: \textUpsilon
+    \cs_new_eq:NN \__chemnum_Phi:     \textPhi
+    \cs_new_eq:NN \__chemnum_Chi:     \textChi
+    \cs_new_eq:NN \__chemnum_Psi:     \textPsi
+    \cs_new_eq:NN \__chemnum_Omega:   \textOmega
   }
   {
     \RequirePackage { bm }% abhängig machen von textoption bold
-    \cs_new_nopar:Npn \chemnum_bm:n #1
+    \cs_new_nopar:Npn \__chemnum_bm:n #1
       {
-        \bool_if:NTF \l_chemnum_cmpd_bold_bool
+        \bool_if:NTF \l__chemnum_cmpd_bold_bool
           { \bm { #1 } }
           { #1 }
       }
-    \cs_new_nopar:Npn \chemnum_alpha:   { \ensuremath { \chemnum_bm:n { \mathrm { \alpha } } } }
-    \cs_new_nopar:Npn \chemnum_beta:    { \ensuremath { \chemnum_bm:n { \mathrm { \beta } } } }
-    \cs_new_nopar:Npn \chemnum_gamma:   { \ensuremath { \chemnum_bm:n { \mathrm { \gamma } } } }
-    \cs_new_nopar:Npn \chemnum_delta:   { \ensuremath { \chemnum_bm:n { \mathrm { \delta } } } }
-    \cs_new_nopar:Npn \chemnum_epsilon: { \ensuremath { \chemnum_bm:n { \mathrm { \varepsilon } } } }
-    \cs_new_nopar:Npn \chemnum_zeta:    { \ensuremath { \chemnum_bm:n { \mathrm { \zeta } } } }
-    \cs_new_nopar:Npn \chemnum_eta:     { \ensuremath { \chemnum_bm:n { \mathrm { \eta } } } }
-    \cs_new_nopar:Npn \chemnum_theta:   { \ensuremath { \chemnum_bm:n { \mathrm { \theta } } } }
-    \cs_new_nopar:Npn \chemnum_iota:    { \ensuremath { \chemnum_bm:n { \mathrm { \iota } } } }
-    \cs_new_nopar:Npn \chemnum_kappa:   { \ensuremath { \chemnum_bm:n { \mathrm { \kappa } } } }
-    \cs_new_nopar:Npn \chemnum_lambda:  { \ensuremath { \chemnum_bm:n { \mathrm { \lampda } } } }
-    \cs_new_nopar:Npn \chemnum_mu:      { \ensuremath { \chemnum_bm:n { \mathrm { \mu } } } }
-    \cs_new_nopar:Npn \chemnum_nu:      { \ensuremath { \chemnum_bm:n { \mathrm { \nu } } } }
-    \cs_new_nopar:Npn \chemnum_xi:      { \ensuremath { \chemnum_bm:n { \mathrm { \xi } } } }
-    \cs_new_nopar:Npn \chemnum_omikron: { \ensuremath { \chemnum_bm:n { \mathrm { o } } } }
-    \cs_new_nopar:Npn \chemnum_pi:      { \ensuremath { \chemnum_bm:n { \mathrm { \pi } } } }
-    \cs_new_nopar:Npn \chemnum_rho:     { \ensuremath { \chemnum_bm:n { \mathrm { \rho } } } }
-    \cs_new_nopar:Npn \chemnum_sigma:   { \ensuremath { \chemnum_bm:n { \mathrm { \sigma } } } }
-    \cs_new_nopar:Npn \chemnum_tau:     { \ensuremath { \chemnum_bm:n { \mathrm { \tau } } } }
-    \cs_new_nopar:Npn \chemnum_upsilon: { \ensuremath { \chemnum_bm:n { \mathrm { \upsilon } } } }
-    \cs_new_nopar:Npn \chemnum_phi:     { \ensuremath { \chemnum_bm:n { \mathrm { \varphi } } } }
-    \cs_new_nopar:Npn \chemnum_chi:     { \ensuremath { \chemnum_bm:n { \mathrm { \chi } } } }
-    \cs_new_nopar:Npn \chemnum_psi:     { \ensuremath { \chemnum_bm:n { \mathrm { \psi } } } }
-    \cs_new_nopar:Npn \chemnum_omega:   { \ensuremath { \chemnum_bm:n { \mathrm { \omega } } } }
-    \cs_new_nopar:Npn \chemnum_Alpha:   { \ensuremath { \chemnum_bm:n { \mathrm { A } } } }
-    \cs_new_nopar:Npn \chemnum_Beta:    { \ensuremath { \chemnum_bm:n { \mathrm { B } } } }
-    \cs_new_nopar:Npn \chemnum_Gamma:   { \ensuremath { \chemnum_bm:n { \mathrm { \Gamma } } } }
-    \cs_new_nopar:Npn \chemnum_Delta:   { \ensuremath { \chemnum_bm:n { \mathrm { \Delta } } } }
-    \cs_new_nopar:Npn \chemnum_Epsilon: { \ensuremath { \chemnum_bm:n { \mathrm { E } } } }
-    \cs_new_nopar:Npn \chemnum_Zeta:    { \ensuremath { \chemnum_bm:n { \mathrm { Z } } } }
-    \cs_new_nopar:Npn \chemnum_Eta:     { \ensuremath { \chemnum_bm:n { \mathrm { H } } } }
-    \cs_new_nopar:Npn \chemnum_Theta:   { \ensuremath { \chemnum_bm:n { \mathrm { \Theta } } } }
-    \cs_new_nopar:Npn \chemnum_Iota:    { \ensuremath { \chemnum_bm:n { \mathrm { I } } } }
-    \cs_new_nopar:Npn \chemnum_Kappa:   { \ensuremath { \chemnum_bm:n { \mathrm { K } } } }
-    \cs_new_nopar:Npn \chemnum_Lambda:  { \ensuremath { \chemnum_bm:n { \mathrm { \Lambda } } } }
-    \cs_new_nopar:Npn \chemnum_Mu:      { \ensuremath { \chemnum_bm:n { \mathrm { M } } } }
-    \cs_new_nopar:Npn \chemnum_Nu:      { \ensuremath { \chemnum_bm:n { \mathrm { N } } } }
-    \cs_new_nopar:Npn \chemnum_Xi:      { \ensuremath { \chemnum_bm:n { \mathrm { \Xi } } } }
-    \cs_new_nopar:Npn \chemnum_Omikron: { \ensuremath { \chemnum_bm:n { \mathrm { O } } } }
-    \cs_new_nopar:Npn \chemnum_Pi:      { \ensuremath { \chemnum_bm:n { \mathrm { \Pi } } } }
-    \cs_new_nopar:Npn \chemnum_Rho:     { \ensuremath { \chemnum_bm:n { \mathrm { P } } } }
-    \cs_new_nopar:Npn \chemnum_Sigma:   { \ensuremath { \chemnum_bm:n { \mathrm { \Sigma } } } }
-    \cs_new_nopar:Npn \chemnum_Tau:     { \ensuremath { \chemnum_bm:n { \mathrm { T } } } }
-    \cs_new_nopar:Npn \chemnum_Upsilon: { \ensuremath { \chemnum_bm:n { \mathrm { \Upsilon } } } }
-    \cs_new_nopar:Npn \chemnum_Phi:     { \ensuremath { \chemnum_bm:n { \mathrm { \Phi } } } }
-    \cs_new_nopar:Npn \chemnum_Chi:     { \ensuremath { \chemnum_bm:n { \mathrm { X } } } }
-    \cs_new_nopar:Npn \chemnum_Psi:     { \ensuremath { \chemnum_bm:n { \mathrm { \Psi } } } }
-    \cs_new_nopar:Npn \chemnum_Omega:   { \ensuremath { \chemnum_bm:n { \mathrm { \Omega } } } }
+    \cs_new_nopar:Npn \__chemnum_alpha:   { \ensuremath { \__chemnum_bm:n { \mathrm { \alpha } } } }
+    \cs_new_nopar:Npn \__chemnum_beta:    { \ensuremath { \__chemnum_bm:n { \mathrm { \beta } } } }
+    \cs_new_nopar:Npn \__chemnum_gamma:   { \ensuremath { \__chemnum_bm:n { \mathrm { \gamma } } } }
+    \cs_new_nopar:Npn \__chemnum_delta:   { \ensuremath { \__chemnum_bm:n { \mathrm { \delta } } } }
+    \cs_new_nopar:Npn \__chemnum_epsilon: { \ensuremath { \__chemnum_bm:n { \mathrm { \varepsilon } } } }
+    \cs_new_nopar:Npn \__chemnum_zeta:    { \ensuremath { \__chemnum_bm:n { \mathrm { \zeta } } } }
+    \cs_new_nopar:Npn \__chemnum_eta:     { \ensuremath { \__chemnum_bm:n { \mathrm { \eta } } } }
+    \cs_new_nopar:Npn \__chemnum_theta:   { \ensuremath { \__chemnum_bm:n { \mathrm { \theta } } } }
+    \cs_new_nopar:Npn \__chemnum_iota:    { \ensuremath { \__chemnum_bm:n { \mathrm { \iota } } } }
+    \cs_new_nopar:Npn \__chemnum_kappa:   { \ensuremath { \__chemnum_bm:n { \mathrm { \kappa } } } }
+    \cs_new_nopar:Npn \__chemnum_lambda:  { \ensuremath { \__chemnum_bm:n { \mathrm { \lampda } } } }
+    \cs_new_nopar:Npn \__chemnum_mu:      { \ensuremath { \__chemnum_bm:n { \mathrm { \mu } } } }
+    \cs_new_nopar:Npn \__chemnum_nu:      { \ensuremath { \__chemnum_bm:n { \mathrm { \nu } } } }
+    \cs_new_nopar:Npn \__chemnum_xi:      { \ensuremath { \__chemnum_bm:n { \mathrm { \xi } } } }
+    \cs_new_nopar:Npn \__chemnum_omikron: { \ensuremath { \__chemnum_bm:n { \mathrm { o } } } }
+    \cs_new_nopar:Npn \__chemnum_pi:      { \ensuremath { \__chemnum_bm:n { \mathrm { \pi } } } }
+    \cs_new_nopar:Npn \__chemnum_rho:     { \ensuremath { \__chemnum_bm:n { \mathrm { \rho } } } }
+    \cs_new_nopar:Npn \__chemnum_sigma:   { \ensuremath { \__chemnum_bm:n { \mathrm { \sigma } } } }
+    \cs_new_nopar:Npn \__chemnum_tau:     { \ensuremath { \__chemnum_bm:n { \mathrm { \tau } } } }
+    \cs_new_nopar:Npn \__chemnum_upsilon: { \ensuremath { \__chemnum_bm:n { \mathrm { \upsilon } } } }
+    \cs_new_nopar:Npn \__chemnum_phi:     { \ensuremath { \__chemnum_bm:n { \mathrm { \varphi } } } }
+    \cs_new_nopar:Npn \__chemnum_chi:     { \ensuremath { \__chemnum_bm:n { \mathrm { \chi } } } }
+    \cs_new_nopar:Npn \__chemnum_psi:     { \ensuremath { \__chemnum_bm:n { \mathrm { \psi } } } }
+    \cs_new_nopar:Npn \__chemnum_omega:   { \ensuremath { \__chemnum_bm:n { \mathrm { \omega } } } }
+    \cs_new_nopar:Npn \__chemnum_Alpha:   { \ensuremath { \__chemnum_bm:n { \mathrm { A } } } }
+    \cs_new_nopar:Npn \__chemnum_Beta:    { \ensuremath { \__chemnum_bm:n { \mathrm { B } } } }
+    \cs_new_nopar:Npn \__chemnum_Gamma:   { \ensuremath { \__chemnum_bm:n { \mathrm { \Gamma } } } }
+    \cs_new_nopar:Npn \__chemnum_Delta:   { \ensuremath { \__chemnum_bm:n { \mathrm { \Delta } } } }
+    \cs_new_nopar:Npn \__chemnum_Epsilon: { \ensuremath { \__chemnum_bm:n { \mathrm { E } } } }
+    \cs_new_nopar:Npn \__chemnum_Zeta:    { \ensuremath { \__chemnum_bm:n { \mathrm { Z } } } }
+    \cs_new_nopar:Npn \__chemnum_Eta:     { \ensuremath { \__chemnum_bm:n { \mathrm { H } } } }
+    \cs_new_nopar:Npn \__chemnum_Theta:   { \ensuremath { \__chemnum_bm:n { \mathrm { \Theta } } } }
+    \cs_new_nopar:Npn \__chemnum_Iota:    { \ensuremath { \__chemnum_bm:n { \mathrm { I } } } }
+    \cs_new_nopar:Npn \__chemnum_Kappa:   { \ensuremath { \__chemnum_bm:n { \mathrm { K } } } }
+    \cs_new_nopar:Npn \__chemnum_Lambda:  { \ensuremath { \__chemnum_bm:n { \mathrm { \Lambda } } } }
+    \cs_new_nopar:Npn \__chemnum_Mu:      { \ensuremath { \__chemnum_bm:n { \mathrm { M } } } }
+    \cs_new_nopar:Npn \__chemnum_Nu:      { \ensuremath { \__chemnum_bm:n { \mathrm { N } } } }
+    \cs_new_nopar:Npn \__chemnum_Xi:      { \ensuremath { \__chemnum_bm:n { \mathrm { \Xi } } } }
+    \cs_new_nopar:Npn \__chemnum_Omikron: { \ensuremath { \__chemnum_bm:n { \mathrm { O } } } }
+    \cs_new_nopar:Npn \__chemnum_Pi:      { \ensuremath { \__chemnum_bm:n { \mathrm { \Pi } } } }
+    \cs_new_nopar:Npn \__chemnum_Rho:     { \ensuremath { \__chemnum_bm:n { \mathrm { P } } } }
+    \cs_new_nopar:Npn \__chemnum_Sigma:   { \ensuremath { \__chemnum_bm:n { \mathrm { \Sigma } } } }
+    \cs_new_nopar:Npn \__chemnum_Tau:     { \ensuremath { \__chemnum_bm:n { \mathrm { T } } } }
+    \cs_new_nopar:Npn \__chemnum_Upsilon: { \ensuremath { \__chemnum_bm:n { \mathrm { \Upsilon } } } }
+    \cs_new_nopar:Npn \__chemnum_Phi:     { \ensuremath { \__chemnum_bm:n { \mathrm { \Phi } } } }
+    \cs_new_nopar:Npn \__chemnum_Chi:     { \ensuremath { \__chemnum_bm:n { \mathrm { X } } } }
+    \cs_new_nopar:Npn \__chemnum_Psi:     { \ensuremath { \__chemnum_bm:n { \mathrm { \Psi } } } }
+    \cs_new_nopar:Npn \__chemnum_Omega:   { \ensuremath { \__chemnum_bm:n { \mathrm { \Omega } } } }
   }
 }
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % TOOLS
-\int_new:N \g_chemnum_cmpd_main_int
-\prop_new:N \g_chemnum_label_prop
-\int_new:N \g_chemnum_cmpd_int
-\tl_new:N \l_chemnum_tmpa_tl
-\tl_new:N \l_chemnum_tmpb_tl
-\clist_new:N \g_chemnum_cmpd_save_clist
+\int_new:N   \g__chemnum_cmpd_main_int
+\prop_new:N  \g__chemnum_label_prop
+\int_new:N   \g__chemnum_cmpd_int
+\tl_new:N    \l__chemnum_tmpa_tl
+\tl_new:N    \l__chemnum_tmpb_tl
+\clist_new:N \g__chemnum_cmpd_save_clist
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % READ FROM PREVIOUS RUN, SAVE FOR NEXT RUN
 % save all labels in a clist
-\cs_new:Npn \chemnum_cmpd_save:n #1
-  { \clist_gput_right:Nn \g_chemnum_cmpd_save_clist { { #1 } } }
+\cs_new:Npn \__chemnum_cmpd_save:n #1
+  { \clist_gput_right:Nn \g__chemnum_cmpd_save_clist { { #1 } } }
 
 \msg_set:nnn { chemnum } { missing-cmpd-file }
   {
@@ -269,18 +269,18 @@
 % available at the next run
 \AtEndDocument
   {
-    \iow_new:N \chemnum_aux_file:
-    \iow_open:Nn \chemnum_aux_file: { ./ \c_job_name_tl . cmpd }
-    \clist_map_inline:Nn \g_chemnum_cmpd_save_clist
+    \iow_new:N \__chemnum_aux_file:
+    \iow_open:Nn \__chemnum_aux_file: { ./ \c_job_name_tl . cmpd }
+    \clist_map_inline:Nn \g__chemnum_cmpd_save_clist
       {
-        \iow_now:Nx \chemnum_aux_file:
+        \iow_now:Nx \__chemnum_aux_file:
           {
             \use:c { cs_new_nopar:cpn } { chemnum_cmpd_ #1 _ref: }
               { \exp_not:f { \use:c { chemnum_cmpd_ #1 : } } }
           }
         \cs_if_exist:cT { chemnum_cmpd_ #1 _min: }
           {
-            \iow_now:Nx \chemnum_aux_file:
+            \iow_now:Nx \__chemnum_aux_file:
               {
                 \use:c { cs_new_nopar:cpn } { chemnum_cmpd_ #1 _min_ref: }
                   { \exp_not:f { \use:c { chemnum_cmpd_ #1 _min: } } }
@@ -288,24 +288,24 @@
           }
         \cs_if_exist:cT { chemnum_cmpd_ #1 _max: }
           {
-            \iow_now:Nx \chemnum_aux_file:
+            \iow_now:Nx \__chemnum_aux_file:
               {
                 \use:c { cs_new_nopar:cpn } { chemnum_cmpd_ #1 _max_ref: }
                   { \exp_not:f { \use:c { chemnum_cmpd_ #1 _max: } } }
               }
           }
       }
-    \iow_close:N \chemnum_aux_file:
+    \iow_close:N \__chemnum_aux_file:
   }
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % COMPOUND LABELS
 % STYLE OF COMPOUND LABEL
-\tl_new:N \l_chemnum_style_tmp_tl
-\bool_new:N \l_chemnum_cmpd_style_is_macro_bool
+\tl_new:N \l__chemnum_style_tmp_tl
+\bool_new:N \l__chemnum_cmpd_style_is_macro_bool
 
 % default style
-\cs_new_nopar:Npn \chemnum_cmpd_style_value:n {  }
+\cs_new_nopar:Npn \__chemnum_cmpd_style_value:n {  }
 
 % error message
 \msg_set:nnn { chemnum } { cmpd-style }
@@ -315,45 +315,45 @@
   }
 
 % set style %TODO
-\cs_new_nopar:Npn \chemnum_cmpd_set_style:n #1
+\cs_new_nopar:Npn \__chemnum_cmpd_set_style:n #1
 %   {
-%     \tl_clear:N \l_chemnum_style_tmp_tl
-%     \tl_map_variable:nNn { #1 } \l_chemnum_style_tmp_tl
+%     \tl_clear:N \l__chemnum_style_tmp_tl
+%     \tl_map_variable:nNn { #1 } \l__chemnum_style_tmp_tl
 %       {
-%         \exp_args:No \token_if_cs:NTF \l_chemnum_style_tmp_tl
-%           { \bool_set_true:N \l_chemnum_cmpd_style_is_macro_bool }
-%           { \bool_set_false:N \l_chemnum_cmpd_style_is_macro_bool }
+%         \exp_args:No \token_if_cs:NTF \l__chemnum_style_tmp_tl
+%           { \bool_set_true:N \l__chemnum_cmpd_style_is_macro_bool }
+%           { \bool_set_false:N \l__chemnum_cmpd_style_is_macro_bool }
 %       }
-%     \bool_if:NTF \l_chemnum_cmpd_style_is_macro_bool
-      { \cs_set_nopar:Npn \chemnum_cmpd_style_value:n { #1 } }
+%     \bool_if:NTF \l__chemnum_cmpd_style_is_macro_bool
+      { \cs_set_nopar:Npn \__chemnum_cmpd_style_value:n { #1 } }
 %       { \msg_error:nnx { chemnum } { cmpd-style } { #1 } }
 %   }
 
 % use style
-\bool_new:N \l_chemnum_cmpd_bold_bool
-\bool_set_true:N \l_chemnum_cmpd_bold_bool
+\bool_new:N \l__chemnum_cmpd_bold_bool
+\bool_set_true:N \l__chemnum_cmpd_bold_bool
 
-\cs_new_nopar:Npn \chemnum_cmpd_use_style:n #1
+\cs_new_nopar:Npn \__chemnum_cmpd_use_style:n #1
   {
     \group_begin:
-      \bool_if:NT \l_chemnum_cmpd_bold_bool
+      \bool_if:NT \l__chemnum_cmpd_bold_bool
         { \bfseries }
-      \chemnum_cmpd_style_value:n { #1 }
+      \__chemnum_cmpd_style_value:n { #1 }
     \group_end:
   }
 
 %-----------------------------------------------------------------------------%
 % prefix, suffix, delimiters, format and separator of compound label
-\tl_new:N \l_chemnum_cmpd_prefix_tl
-\tl_new:N \l_chemnum_cmpd_suffix_tl
+\tl_new:N \l__chemnum_cmpd_prefix_tl
+\tl_new:N \l__chemnum_cmpd_suffix_tl
 
-\tl_new:N \l_chemnum_cmpd_space_tl
-\tl_set:Nn \l_chemnum_cmpd_space_tl { \penalty\@m\  }
+\tl_new:N \l__chemnum_cmpd_space_tl
+\tl_set:Nn \l__chemnum_cmpd_space_tl { \penalty\@m\  }
 
-\tl_new:N \l_chemnum_cmpd_separator_tl
+\tl_new:N \l__chemnum_cmpd_separator_tl
 
-\tl_new:N \l_chemnum_cmpd_odelim_tl
-\tl_new:N \l_chemnum_cmpd_cdelim_tl
+\tl_new:N \l__chemnum_cmpd_odelim_tl
+\tl_new:N \l__chemnum_cmpd_cdelim_tl
 
 % error message for wrong argument length of delim-keys
 \msg_set:nnn { chemnum } { delimiters }
@@ -363,74 +363,74 @@
   }
 
 % set compound delimiters
-\cs_new_nopar:Npn \chemnum_cmpd_delim:n #1
+\cs_new_nopar:Npn \__chemnum_cmpd_delim:n #1
   {
     \tl_if_blank:nTF { #1 }
       {
-        \tl_clear:N \l_chemnum_cmpd_odelim_tl
-        \tl_clear:N \l_chemnum_cmpd_cdelim_tl
+        \tl_clear:N \l__chemnum_cmpd_odelim_tl
+        \tl_clear:N \l__chemnum_cmpd_cdelim_tl
       }
       {
         \int_compare:nNnTF { \tl_length:n { #1 } } = 2
           {
-            \tl_set:Nx \l_chemnum_cmpd_odelim_tl { \tl_head:n { #1 } }
-            \tl_set:Nx \l_chemnum_cmpd_cdelim_tl { \tl_tail:n { #1 } }
+            \tl_set:Nx \l__chemnum_cmpd_odelim_tl { \tl_head:n { #1 } }
+            \tl_set:Nx \l__chemnum_cmpd_cdelim_tl { \tl_tail:n { #1 } }
           }
           { \msg_error:nnx { chemnum } { delimiters } { cmpd } }
       }
   } 
 
 % format of numbering
-\cs_new_nopar:Npn \chemnum_cmpd_kind:nn #1#2
+\cs_new_nopar:Npn \__chemnum_cmpd_kind:nn #1#2
   { \cs:w int_to_#1:n \cs_end: #2 }
 
 % default format
-\tl_new:N \l_chemnum_cmpd_kind_value_tl
-\tl_set:Nn \l_chemnum_cmpd_kind_value_tl { arabic }
+\tl_new:N  \l__chemnum_cmpd_kind_value_tl
+\tl_set:Nn \l__chemnum_cmpd_kind_value_tl { arabic }
 
 % format of sub-numbering
-\cs_new_nopar:Npn \chemnum_cmpd_sub_kind:nn #1#2
+\cs_new_nopar:Npn \__chemnum_cmpd_sub_kind:nn #1#2
   { \cs:w int_to_ #1 :n \cs_end: #2 }
-\cs_generate_variant:Nn \chemnum_cmpd_sub_kind:nn { Nc }
+\cs_generate_variant:Nn \__chemnum_cmpd_sub_kind:nn { Nc }
 
 % default format
-\tl_new:N \l_chemnum_cmpd_sub_kind_value_tl
-\tl_set:Nn \l_chemnum_cmpd_sub_kind_value_tl { alph }
+\tl_new:N  \l__chemnum_cmpd_sub_kind_value_tl
+\tl_set:Nn \l__chemnum_cmpd_sub_kind_value_tl { alph }
 
 %-----------------------------------------------------------------------------%
 % add greek letters and symbols as numbering format
 % define \int_to_greek function
 \cs_new:Npn \int_to_greek:n { }
-% \bool_if:NTF \l_chemnum_textgreek_bool
+% \bool_if:NTF \l__chemnum_textgreek_bool
 %   {
     \cs_set:Npn \int_to_greek:n #1
       {
         \int_to_symbols:nnn {#1} { 24 }
           {
-            {  1 } { \exp_not:o \chemnum_alpha: }
-            {  2 } { \exp_not:o \chemnum_beta: }
-            {  3 } { \exp_not:o \chemnum_gamma: }
-            {  4 } { \exp_not:o \chemnum_delta: }
-            {  5 } { \exp_not:o \chemnum_epsilon: }
-            {  6 } { \exp_not:o \chemnum_zeta: }
-            {  7 } { \exp_not:o \chemnum_eta: }
-            {  8 } { \exp_not:o \chemnum_theta: }
-            {  9 } { \exp_not:o \chemnum_iota: }
-            { 10 } { \exp_not:o \chemnum_kappa: }
-            { 11 } { \exp_not:o \chemnum_lambda: }
-            { 12 } { \exp_not:o \chemnum_mu: }
-            { 13 } { \exp_not:o \chemnum_nu: }
-            { 14 } { \exp_not:o \chemnum_xi: }
-            { 15 } { \exp_not:o \chemnum_omikron: }
-            { 16 } { \exp_not:o \chemnum_pi: }
-            { 17 } { \exp_not:o \chemnum_rho: }
-            { 18 } { \exp_not:o \chemnum_sigma: }
-            { 19 } { \exp_not:o \chemnum_tau: }
-            { 20 } { \exp_not:o \chemnum_upsilon: }
-            { 21 } { \exp_not:o \chemnum_phi: }
-            { 22 } { \exp_not:o \chemnum_chi: }
-            { 23 } { \exp_not:o \chemnum_psi: }
-            { 24 } { \exp_not:o \chemnum_omega: }
+            {  1 } { \exp_not:o \__chemnum_alpha: }
+            {  2 } { \exp_not:o \__chemnum_beta: }
+            {  3 } { \exp_not:o \__chemnum_gamma: }
+            {  4 } { \exp_not:o \__chemnum_delta: }
+            {  5 } { \exp_not:o \__chemnum_epsilon: }
+            {  6 } { \exp_not:o \__chemnum_zeta: }
+            {  7 } { \exp_not:o \__chemnum_eta: }
+            {  8 } { \exp_not:o \__chemnum_theta: }
+            {  9 } { \exp_not:o \__chemnum_iota: }
+            { 10 } { \exp_not:o \__chemnum_kappa: }
+            { 11 } { \exp_not:o \__chemnum_lambda: }
+            { 12 } { \exp_not:o \__chemnum_mu: }
+            { 13 } { \exp_not:o \__chemnum_nu: }
+            { 14 } { \exp_not:o \__chemnum_xi: }
+            { 15 } { \exp_not:o \__chemnum_omikron: }
+            { 16 } { \exp_not:o \__chemnum_pi: }
+            { 17 } { \exp_not:o \__chemnum_rho: }
+            { 18 } { \exp_not:o \__chemnum_sigma: }
+            { 19 } { \exp_not:o \__chemnum_tau: }
+            { 20 } { \exp_not:o \__chemnum_upsilon: }
+            { 21 } { \exp_not:o \__chemnum_phi: }
+            { 22 } { \exp_not:o \__chemnum_chi: }
+            { 23 } { \exp_not:o \__chemnum_psi: }
+            { 24 } { \exp_not:o \__chemnum_omega: }
           }
       }
 %   }
@@ -440,36 +440,36 @@
 
 % define \int_to_Greek function
 \cs_new:Npn \int_to_Greek:n { }
-\bool_if:NTF \l_chemnum_textgreek_bool
+\bool_if:NTF \l__chemnum_textgreek_bool
   {
     \cs_set:Npn \int_to_Greek:n #1
       {
         \int_to_symbols:nnn { #1 } { 24 }
           {
-            {  1 } { \exp_not:o \chemnum_Alpha: }
-            {  2 } { \exp_not:o \chemnum_Beta: }
-            {  3 } { \exp_not:o \chemnum_Gamma: }
-            {  4 } { \exp_not:o \chemnum_Delta: }
-            {  5 } { \exp_not:o \chemnum_Epsilon: }
-            {  6 } { \exp_not:o \chemnum_Zeta: }
-            {  7 } { \exp_not:o \chemnum_Eta: }
-            {  8 } { \exp_not:o \chemnum_Theta: }
-            {  9 } { \exp_not:o \chemnum_Iota: }
-            { 10 } { \exp_not:o \chemnum_Kappa: }
-            { 11 } { \exp_not:o \chemnum_Lambda: }
-            { 12 } { \exp_not:o \chemnum_Mu: }
-            { 13 } { \exp_not:o \chemnum_Nu: }
-            { 14 } { \exp_not:o \chemnum_Xi: }
-            { 15 } { \exp_not:o \chemnum_Omikron: }
-            { 16 } { \exp_not:o \chemnum_Pi: }
-            { 17 } { \exp_not:o \chemnum_Rho: }
-            { 18 } { \exp_not:o \chemnum_Sigma: }
-            { 19 } { \exp_not:o \chemnum_Tau: }
-            { 20 } { \exp_not:o \chemnum_Upsilon: }
-            { 21 } { \exp_not:o \chemnum_Phi: }
-            { 22 } { \exp_not:o \chemnum_Chi: }
-            { 23 } { \exp_not:o \chemnum_Psi: }
-            { 24 } { \exp_not:o \chemnum_Omega: }
+            {  1 } { \exp_not:o \__chemnum_Alpha: }
+            {  2 } { \exp_not:o \__chemnum_Beta: }
+            {  3 } { \exp_not:o \__chemnum_Gamma: }
+            {  4 } { \exp_not:o \__chemnum_Delta: }
+            {  5 } { \exp_not:o \__chemnum_Epsilon: }
+            {  6 } { \exp_not:o \__chemnum_Zeta: }
+            {  7 } { \exp_not:o \__chemnum_Eta: }
+            {  8 } { \exp_not:o \__chemnum_Theta: }
+            {  9 } { \exp_not:o \__chemnum_Iota: }
+            { 10 } { \exp_not:o \__chemnum_Kappa: }
+            { 11 } { \exp_not:o \__chemnum_Lambda: }
+            { 12 } { \exp_not:o \__chemnum_Mu: }
+            { 13 } { \exp_not:o \__chemnum_Nu: }
+            { 14 } { \exp_not:o \__chemnum_Xi: }
+            { 15 } { \exp_not:o \__chemnum_Omikron: }
+            { 16 } { \exp_not:o \__chemnum_Pi: }
+            { 17 } { \exp_not:o \__chemnum_Rho: }
+            { 18 } { \exp_not:o \__chemnum_Sigma: }
+            { 19 } { \exp_not:o \__chemnum_Tau: }
+            { 20 } { \exp_not:o \__chemnum_Upsilon: }
+            { 21 } { \exp_not:o \__chemnum_Phi: }
+            { 22 } { \exp_not:o \__chemnum_Chi: }
+            { 23 } { \exp_not:o \__chemnum_Psi: }
+            { 24 } { \exp_not:o \__chemnum_Omega: }
           }
       }
   }
@@ -496,111 +496,103 @@
 
 %-----------------------------------------------------------------------------%
 % lists of sublabels
-\clist_new:N \l_chemnum_sublabel_clist
-\tl_new:N \l_chemnum_sublabel_list_sep_tl
-\tl_set:Nn \l_chemnum_sublabel_list_sep_tl { , }
-\tl_new:N \l_chemnum_cmpd_sublabel_list_tl
-\int_new:N \l_chemnum_sublabel_list_current_int
-\int_new:N \l_chemnum_sublabel_list_length_int
-\bool_new:N \l_chemnum_sublabel_list_bool
-
-\cs_new_nopar:Npn \chemnum_cmpd_sublabel_list:nn #1#2
+\clist_new:N \l__chemnum_sublabel_clist
+\tl_new:N    \l__chemnum_sublabel_list_sep_tl
+\tl_set:Nn   \l__chemnum_sublabel_list_sep_tl { , }
+\tl_new:N    \l__chemnum_cmpd_sublabel_list_tl
+\int_new:N   \l__chemnum_sublabel_list_current_int
+\int_new:N   \l__chemnum_sublabel_list_length_int
+\bool_new:N  \l__chemnum_sublabel_list_bool
+
+\cs_new_nopar:Npn \__chemnum_cmpd_sublabel_list:nn #1#2
   {
-    \clist_clear:N \l_chemnum_sublabel_clist
-    \clist_set_eq:NN \l_chemnum_sublabel_clist #2
-    \int_set:Nn \l_chemnum_sublabel_list_length_int
-      { \clist_length:N \l_chemnum_sublabel_clist }
-    \clist_map_variable:NNn \l_chemnum_sublabel_clist \l_chemnum_tmpb_tl
+    \clist_clear:N \l__chemnum_sublabel_clist
+    \clist_set_eq:NN \l__chemnum_sublabel_clist #2
+    \int_set:Nn \l__chemnum_sublabel_list_length_int
+      { \clist_length:N \l__chemnum_sublabel_clist }
+    \clist_map_variable:NNn \l__chemnum_sublabel_clist \l__chemnum_tmpb_tl
       {
-        \int_incr:N \l_chemnum_sublabel_list_current_int
-        \exp_after:wN \chemnum_cmpd_sublabelsep:n \l_chemnum_tmpb_tl \q_stop
-        \use:c { chemnum_cmpd_#1_ \l_chemnum_cmpd_sub_one_label_tl _ref: }
-        \exp_args:No \tl_if_blank:nF { \l_chemnum_cmpd_sub_two_label_tl }
+        \int_incr:N \l__chemnum_sublabel_list_current_int
+        \exp_after:wN \__chemnum_cmpd_sublabelsep:n \l__chemnum_tmpb_tl \q_stop
+        \use:c { chemnum_cmpd_#1_ \l__chemnum_cmpd_sub_one_label_tl _ref: }
+        \exp_args:No \tl_if_blank:nF { \l__chemnum_cmpd_sub_two_label_tl }
           {
-            \tl_use:N \l_chemnum_sub_range_sep_tl
-            \use:c { chemnum_cmpd_#1_ \l_chemnum_cmpd_sub_two_label_tl _ref: }
+            \tl_use:N \l__chemnum_sub_range_sep_tl
+            \use:c { chemnum_cmpd_#1_ \l__chemnum_cmpd_sub_two_label_tl _ref: }
           }
         \int_compare:nT
           {
-            \l_chemnum_sublabel_list_current_int
+            \l__chemnum_sublabel_list_current_int
             <
-            \l_chemnum_sublabel_list_length_int
+            \l__chemnum_sublabel_list_length_int
           }
-          { \tl_use:N \l_chemnum_sublabel_list_sep_tl }
+          { \tl_use:N \l__chemnum_sublabel_list_sep_tl }
       }
   }
 
 %-----------------------------------------------------------------------------%
 % variables
-\tl_new:N \l_chemnum_cmpd_name_tl
-
-\bool_new:N \l_chemnum_cmpd_name_bool
-\bool_set_false:N \l_chemnum_cmpd_name_bool
-
-\bool_new:N \l_chemnum_cmpd_all_bool
-\bool_set_false:N \l_chemnum_cmpd_all_bool
-
-\bool_new:N \l_chemnum_cmpd_range_bool
-\bool_set_false:N \l_chemnum_cmpd_range_bool
-
-\tl_new:N \l_chemnum_cmpd_labelsep_tl
-\tl_set:Nn \l_chemnum_cmpd_labelsep_tl { . }
-
-\tl_new:N \l_chemnum_sublist_input_separator_tl
-\tl_set:Nn \l_chemnum_sublist_input_separator_tl { , }
-
-\tl_new:N \l_chemnum_sublist_output_separator_tl
-\tl_set:Nn \l_chemnum_sublist_output_separator_tl { , }
-
-\tl_new:N \l_chemnum_sublabel_range_marker_tl
-\tl_set:Nn \l_chemnum_sublabel_range_marker_tl { .. }
-
-\tl_new:N \l_chemnum_sub_range_sep_tl
-\tl_set:Nn \l_chemnum_sub_range_sep_tl { -- }
-
-\bool_new:N \l_chemnum_sub_label_only_bool
-\bool_set_false:N \l_chemnum_sub_label_only_bool
+\bool_new:N \l__chemnum_cmpd_name_bool
+\bool_set_false:N \l__chemnum_cmpd_name_bool
+\bool_new:N \l__chemnum_cmpd_all_bool
+\bool_set_false:N \l__chemnum_cmpd_all_bool
+\bool_new:N \l__chemnum_cmpd_range_bool
+\bool_set_false:N \l__chemnum_cmpd_range_bool
+\bool_new:N \l__chemnum_sub_label_only_bool
+\bool_set_false:N \l__chemnum_sub_label_only_bool
+
+\tl_new:N  \l__chemnum_cmpd_name_tl
+\tl_new:N  \l__chemnum_cmpd_labelsep_tl
+\tl_set:Nn \l__chemnum_cmpd_labelsep_tl { . }
+\tl_new:N  \l__chemnum_sublist_input_separator_tl
+\tl_set:Nn \l__chemnum_sublist_input_separator_tl { , }
+\tl_new:N  \l__chemnum_sublist_output_separator_tl
+\tl_set:Nn \l__chemnum_sublist_output_separator_tl { , }
+\tl_new:N  \l__chemnum_sublabel_range_marker_tl
+\tl_set:Nn \l__chemnum_sublabel_range_marker_tl { .. }
+\tl_new:N  \l__chemnum_sub_range_sep_tl
+\tl_set:Nn \l__chemnum_sub_range_sep_tl { -- }
 
 %-----------------------------------------------------------------------------%
 % hyperref support
-\tl_new:N \l_chemnum_cmpd_hyper_name_tl
+\tl_new:N \l__chemnum_cmpd_hyper_name_tl
 
-\bool_new:N \l_chemnum_use_hyperref_bool
-\bool_new:N \l_chemnum_hypertarget_bool
-\bool_new:N \l_chemnum_hyperlink_bool
+\bool_new:N \l__chemnum_use_hyperref_bool
+\bool_new:N \l__chemnum_hypertarget_bool
+\bool_new:N \l__chemnum_hyperlink_bool
 
-\cs_new_eq:NN \chemnum_make_hyper:nn \use_ii:nn
+\cs_new_eq:NN \__chemnum_make_hyper:nn \use_ii:nn
 
 % #1: main label, #2: sub labels, #3: invisible
-\cs_new_nopar:Npn \chemnum_hyperref:nnn #1#2#3
+\cs_new_nopar:Npn \__chemnum_hyperref:nnn #1#2#3
    {
-     \bool_if:nF { #3 || !\l_chemnum_use_hyperref_bool }
+     \bool_if:nF { #3 || !\l__chemnum_use_hyperref_bool }
        {
-         \bool_if:NT \l_chemnum_hypertarget_bool
+         \bool_if:NT \l__chemnum_hypertarget_bool
            {
-             \cs_set_nopar:Npn \chemnum_make_hyper:nn ##1##2
+             \cs_set_nopar:Npn \__chemnum_make_hyper:nn ##1##2
                {
                  \raisebox { 3ex } [ 0pt ]
                    { \hypertarget { ##1 } { } } ##2
                }
            }
-         \bool_if:NT \l_chemnum_hyperlink_bool
-           { \cs_set_eq:NN \chemnum_make_hyper:nn \hyperlink }
+         \bool_if:NT \l__chemnum_hyperlink_bool
+           { \cs_set_eq:NN \__chemnum_make_hyper:nn \hyperlink }
          \bool_if:nT
-           { !\l_chemnum_hypertarget_bool && !\l_chemnum_hyperlink_bool }
+           { !\l__chemnum_hypertarget_bool && !\l__chemnum_hyperlink_bool }
            {
              \tl_if_blank:nTF { #2 }
                { % no sublabel
-                 \tl_set:Nn \l_chemnum_cmpd_hyper_name_tl
+                 \tl_set:Nn \l__chemnum_cmpd_hyper_name_tl
                    { chemnum_cmpd_#1 }
                  \cs_if_exist:cTF { chemnum_cmpd_#1_hyper: }
                    {
-                     \bool_set_false:N \l_chemnum_hypertarget_bool
-                     \cs_set_eq:NN \chemnum_make_hyper:nn \hyperlink
+                     \bool_set_false:N \l__chemnum_hypertarget_bool
+                     \cs_set_eq:NN \__chemnum_make_hyper:nn \hyperlink
                    }
                    {
-                     \bool_set_true:N \l_chemnum_hypertarget_bool
-                     \cs_set_nopar:Npn \chemnum_make_hyper:nn ##1##2
+                     \bool_set_true:N \l__chemnum_hypertarget_bool
+                     \cs_set_nopar:Npn \__chemnum_make_hyper:nn ##1##2
                        {
                          \raisebox { 3ex } [ 0pt ]
                            { \hypertarget { ##1 } { } } ##2
@@ -609,23 +601,23 @@
                    }
                }
                {
-                 \chemnum_cmpd_sublist:n { #2 }
-                 \int_compare:nT { \l_chemnum_cmpd_sublist_length_int < 2 }
+                 \__chemnum_cmpd_sublist:n { #2 }
+                 \int_compare:nT { \l__chemnum_cmpd_sublist_length_int < 2 }
                    { % no sublabel list
-                     \chemnum_cmpd_subrange_separate:n { #2 }
+                     \__chemnum_cmpd_subrange_separate:n { #2 }
                      \tl_if_blank:VT \l_tmpb_tl
                        { % no sublabel range
-                         \tl_set:Nn \l_chemnum_cmpd_hyper_name_tl
+                         \tl_set:Nn \l__chemnum_cmpd_hyper_name_tl
                            { chemnum_cmpd_#1_\l_tmpa_tl }
                          \cs_if_exist:cTF
                            { chemnum_cmpd_#1_ \l_tmpa_tl _hyper: }
                            {
-                             \bool_set_false:N \l_chemnum_hypertarget_bool
-                             \cs_set_eq:NN \chemnum_make_hyper:nn \hyperlink
+                             \bool_set_false:N \l__chemnum_hypertarget_bool
+                             \cs_set_eq:NN \__chemnum_make_hyper:nn \hyperlink
                            }
                            {
-                             \bool_set_true:N \l_chemnum_hypertarget_bool
-                             \cs_set_nopar:Npn \chemnum_make_hyper:nn ##1##2
+                             \bool_set_true:N \l__chemnum_hypertarget_bool
+                             \cs_set_nopar:Npn \__chemnum_make_hyper:nn ##1##2
                                {
                                  \raisebox { 3ex } [ 0pt ]
                                    { \hypertarget { ##1 } { } } ##2
@@ -643,128 +635,121 @@
 %-----------------------------------------------------------------------------%
 % property keys for compounds
 \keys_define:nn { chemnum } {
-  cmpd-style           .code:n             = \chemnum_cmpd_set_style:n { #1 } ,
+  cmpd-style           .code:n             = \__chemnum_cmpd_set_style:n { #1 } ,
   cmpd-weight          .choice: ,
   cmpd-weight / bold   .code:n             =
-    \bool_set_true:N \l_chemnum_cmpd_bold_bool ,
+    \bool_set_true:N \l__chemnum_cmpd_bold_bool ,
   cmpd-weight / normal .code:n             =
-    \bool_set_false:N \l_chemnum_cmpd_bold_bool ,
+    \bool_set_false:N \l__chemnum_cmpd_bold_bool ,
   cmpd-label           .code:n             =
     {
-      \bool_set_true:N \l_chemnum_cmpd_name_bool
-      \tl_set:Nn \l_chemnum_cmpd_name_tl { #1 }
+      \bool_set_true:N \l__chemnum_cmpd_name_bool
+      \tl_set:Nn \l__chemnum_cmpd_name_tl { #1 }
     } ,
-  cmpd-prefix          .tl_set:N           = \l_chemnum_cmpd_prefix_tl ,
+  cmpd-prefix          .tl_set:N           = \l__chemnum_cmpd_prefix_tl ,
   cmpd-prefix          .default:n          = { } ,
-  cmpd-suffix          .tl_set:N           = \l_chemnum_cmpd_suffix_tl ,
+  cmpd-suffix          .tl_set:N           = \l__chemnum_cmpd_suffix_tl ,
   cmpd-suffix          .default:n          = { } ,
-  cmpd-space           .tl_set:N           = \l_chemnum_cmpd_space_tl ,
+  cmpd-space           .tl_set:N           = \l__chemnum_cmpd_space_tl ,
   cmpd-space           .default:n          = { \penalty\@m\  },
-  cmpd-delim           .code:n             = \chemnum_cmpd_delim:n { #1 },
+  cmpd-delim           .code:n             = \__chemnum_cmpd_delim:n { #1 },
   cmpd-delim           .default:n          = { ( } { ) } ,
-  cmpd-odelim          .tl_set:N           = \l_chemnum_cmpd_odelim_tl ,
+  cmpd-odelim          .tl_set:N           = \l__chemnum_cmpd_odelim_tl ,
   cmpd-odelim          .default:n          = { } ,
-  cmpd-cdelim          .tl_set:N           = \l_chemnum_cmpd_cdelim_tl ,
+  cmpd-cdelim          .tl_set:N           = \l__chemnum_cmpd_cdelim_tl ,
   cmpd-cdelim          .default:n          = { } ,
-  cmpd-all             .bool_set:N         = \l_chemnum_cmpd_all_bool ,
+  cmpd-all             .bool_set:N         = \l__chemnum_cmpd_all_bool ,
   cmpd-all             .default:n          = true ,
   cmpd-counter         .choice: ,
   cmpd-counter         .choice_code:n      =
-    \tl_set_eq:NN \l_chemnum_cmpd_kind_value_tl \l_keys_choice_tl ,
+    \tl_set_eq:NN \l__chemnum_cmpd_kind_value_tl \l_keys_choice_tl ,
   cmpd-counter         .generate_choices:n =
     { arabic , alph , Alph , greek, Greek , roman , Roman , Symbol } ,
   cmpd-counter         .default:n          = arabic ,
   hyper-use            .choice: ,
   hyper-use / true     .code:n             =
     {
-      \bool_set_true:N \l_chemnum_use_hyperref_bool
-      \bool_set_false:N \l_chemnum_hypertarget_bool
-      \bool_set_false:N \l_chemnum_hyperlink_bool
+      \bool_set_true:N \l__chemnum_use_hyperref_bool
+      \bool_set_false:N \l__chemnum_hypertarget_bool
+      \bool_set_false:N \l__chemnum_hyperlink_bool
     } ,
   hyper-use / false    .code:n             =
     {
-      \bool_set_false:N \l_chemnum_use_hyperref_bool
-      \bool_set_false:N \l_chemnum_hypertarget_bool
-      \bool_set_false:N \l_chemnum_hyperlink_bool
+      \bool_set_false:N \l__chemnum_use_hyperref_bool
+      \bool_set_false:N \l__chemnum_hypertarget_bool
+      \bool_set_false:N \l__chemnum_hyperlink_bool
     } ,
   hyper-use            .default:n          = true ,
   hyper-target         .code:n             =
     {
-      \tl_set:Nn \l_chemnum_cmpd_hyper_name_tl { #1 }
-      \bool_set_true:N \l_chemnum_use_hyperref_bool
-      \bool_set_true:N \l_chemnum_hypertarget_bool
-      \bool_set_false:N \l_chemnum_hyperlink_bool
+      \tl_set:Nn \l__chemnum_cmpd_hyper_name_tl { #1 }
+      \bool_set_true:N \l__chemnum_use_hyperref_bool
+      \bool_set_true:N \l__chemnum_hypertarget_bool
+      \bool_set_false:N \l__chemnum_hyperlink_bool
     } ,
   hyper-link           .code:n             =
     {
-      \tl_set:Nn \l_chemnum_cmpd_hyper_name_tl { #1 }
-      \bool_set_true:N \l_chemnum_use_hyperref_bool
-      \bool_set_false:N \l_chemnum_hypertarget_bool
-      \bool_set_true:N \l_chemnum_hyperlink_bool
+      \tl_set:Nn \l__chemnum_cmpd_hyper_name_tl { #1 }
+      \bool_set_true:N \l__chemnum_use_hyperref_bool
+      \bool_set_false:N \l__chemnum_hypertarget_bool
+      \bool_set_true:N \l__chemnum_hyperlink_bool
     } ,
   sub-counter          .choice: ,
   sub-counter          .choice_code:n      =
-    \tl_set_eq:NN \l_chemnum_cmpd_sub_kind_value_tl \l_keys_choice_tl ,
+    \tl_set_eq:NN \l__chemnum_cmpd_sub_kind_value_tl \l_keys_choice_tl ,
   sub-counter          .generate_choices:n =
     { arabic , alph , Alph , greek , Greek , roman , Roman , Symbol } ,
   sub-counter          .default:n          = alph ,
-  sub-input-sep        .code:n             = \chemnum_subcmpdsep:n { #1 } ,
+  sub-input-sep        .code:n             = \__chemnum_subcmpdsep:n { #1 } ,
   sub-input-sep        .default:n          = . ,
-  sub-output-sep       .tl_set:N           = \l_chemnum_cmpd_separator_tl ,
+  sub-output-sep       .tl_set:N           = \l__chemnum_cmpd_separator_tl ,
   sub-output-sep       .default:n          = { } ,
   sublist-input-sep    .tl_set:N           =
-    \l_chemnum_sublist_input_separator_tl ,
+    \l__chemnum_sublist_input_separator_tl ,
   sublist-input-sep    .default:n          = { , } ,
   sublist-output-sep   .tl_set:N           =
-    \l_chemnum_sublist_output_separator_tl ,
+    \l__chemnum_sublist_output_separator_tl ,
   sublist-output-sep   .default:n          = { , } ,
-  sub-only             .bool_set:N         = \l_chemnum_sub_label_only_bool ,
+  sub-only             .bool_set:N         = \l__chemnum_sub_label_only_bool ,
   sub-only             .default:n          = true ,
-  subrange-output-sep  .tl_set:N           = \l_chemnum_sub_range_sep_tl ,
+  subrange-output-sep  .tl_set:N           = \l__chemnum_sub_range_sep_tl ,
   subrange-output-sep  .default:n          = { -- } ,
   subrange-input-sep   .code:n             =
-    \chemnum_sublabel_range_marker:n { #1 } ,
+    \__chemnum_sublabel_range_marker:n { #1 } ,
   subrange-input-sep   .default:n          = { .. }
 }
 
 %-----------------------------------------------------------------------------%
 % list separators, delimiters, prefix and suffix
-\bool_new:N \l_chemnum_no_serial_comma_bool
-\bool_set_false:N \l_chemnum_no_serial_comma_bool
-
-\tl_new:N \l_chemnum_list_input_separator_tl
-\tl_set:Nn \l_chemnum_list_input_separator_tl { , }
-
-\tl_new:N \l_chemnum_list_separator_tl
-\tl_set:Nn \l_chemnum_list_separator_tl { , }
-
-\tl_new:N \l_chemunm_list_space_tl
-\tl_set:Nn \l_chemnum_list_space_tl { \penalty\@m\  }
-
-\tl_new:N \l_chemnum_list_last_separator_lang_tl
-\tl_set:Nn \l_chemnum_list_last_separator_lang_tl { and }
-
-\tl_new:N \l_chemnum_list_last_separator_tl
-\tl_set:Nn \l_chemnum_list_last_separator_tl
-  { \tl_use:N \l_chemnum_list_last_separator_lang_tl }
-
-\tl_new:N \l_chemnum_list_prefix_tl { }
-\tl_set:Nn \l_chemnum_list_prefix_tl { }
-
-\tl_new:N \l_chemnum_list_suffix_tl { }
-\tl_set:Nn \l_chemnum_list_suffix_tl { }
-
-\tl_new:N \l_chemnum_list_odelim_tl { }
-\tl_new:N \l_chemnum_list_cdelim_tl { }
-
-\cs_new_nopar:Npn \chemnum_list_delim:n #1 {
+\bool_new:N \l__chemnum_no_serial_comma_bool
+\bool_set_false:N \l__chemnum_no_serial_comma_bool
+
+\tl_new:N  \l__chemnum_list_input_separator_tl
+\tl_set:Nn \l__chemnum_list_input_separator_tl { , }
+\tl_new:N  \l__chemnum_list_separator_tl
+\tl_set:Nn \l__chemnum_list_separator_tl { , }
+\tl_new:N  \l__chemnum_list_space_tl
+\tl_set:Nn \l__chemnum_list_space_tl { \penalty\@m\  }
+\tl_new:N  \l__chemnum_list_last_separator_lang_tl
+\tl_set:Nn \l__chemnum_list_last_separator_lang_tl { and }
+\tl_new:N  \l__chemnum_list_last_separator_tl
+\tl_set:Nn \l__chemnum_list_last_separator_tl
+  { \tl_use:N \l__chemnum_list_last_separator_lang_tl }
+\tl_new:N  \l__chemnum_list_prefix_tl { }
+\tl_set:Nn \l__chemnum_list_prefix_tl { }
+\tl_new:N  \l__chemnum_list_suffix_tl { }
+\tl_set:Nn \l__chemnum_list_suffix_tl { }
+\tl_new:N  \l__chemnum_list_odelim_tl { }
+\tl_new:N  \l__chemnum_list_cdelim_tl { }
+
+\cs_new_nopar:Npn \__chemnum_list_delim:n #1 {
   \tl_if_blank:nTF { #1 } {
-    \tl_clear:N \l_chemnum_list_odelim_tl
-    \tl_clear:N \l_chemnum_list_cdelim_tl
+    \tl_clear:N \l__chemnum_list_odelim_tl
+    \tl_clear:N \l__chemnum_list_cdelim_tl
   }{
     \int_compare:nNnTF { \tl_length:n { #1 } } = 2 {
-      \tl_set:Nx \l_chemnum_list_odelim_tl { \tl_head:n { #1 } }
-      \tl_set:Nx \l_chemnum_list_cdelim_tl { \tl_tail:n { #1 } }
+      \tl_set:Nx \l__chemnum_list_odelim_tl { \tl_head:n { #1 } }
+      \tl_set:Nx \l__chemnum_list_cdelim_tl { \tl_tail:n { #1 } }
     }{ \msg_error:nnx { chemnum } { delimiters } { list } }
   }
 }
@@ -772,102 +757,102 @@
 %-----------------------------------------------------------------------------%
 % property keys for lists
 \keys_define:nn { chemnum } {
-  list-prefix        .tl_set:N   = \l_chemnum_list_prefix_tl ,
+  list-prefix        .tl_set:N   = \l__chemnum_list_prefix_tl ,
   list-prefix        .default:n  = { } ,
-  list-suffix        .tl_set:N   = \l_chemnum_list_suffix_tl ,
+  list-suffix        .tl_set:N   = \l__chemnum_list_suffix_tl ,
   list-suffix        .default:n  = { } ,
-  list-delim         .code:n     = \chemnum_list_delim:n { #1 } ,
+  list-delim         .code:n     = \__chemnum_list_delim:n { #1 } ,
   list-delim         .default:n  = { ( } { ) } ,
-  list-odelim        .tl_set:N   = \l_chemnum_list_odelim_tl ,
+  list-odelim        .tl_set:N   = \l__chemnum_list_odelim_tl ,
   list-odelim        .default:n  = { } ,
-  list-cdelim        .tl_set:N   = \l_chemnum_list_cdelim_tl ,
+  list-cdelim        .tl_set:N   = \l__chemnum_list_cdelim_tl ,
   list-cdelim        .default:n  = { } ,
-  list-space         .tl_set:N   = \l_chemnum_list_space_tl ,
+  list-space         .tl_set:N   = \l__chemnum_list_space_tl ,
   list-space         .default:n  = { \penalty\@m\  } ,
-  list-input-sep     .tl_set:N   = \l_chemnum_list_input_separator_tl ,
+  list-input-sep     .tl_set:N   = \l__chemnum_list_input_separator_tl ,
   list-input-sep     .default:n  = { , } ,
-  list-output-sep    .tl_set:N   = \l_chemnum_list_separator_tl ,
+  list-output-sep    .tl_set:N   = \l__chemnum_list_separator_tl ,
   list-output-sep    .default:n  = { , } ,
-  list-last-sep      .tl_set:N   = \l_chemnum_list_last_separator_tl ,
-  list-last-sep      .default:n  = \l_chemnum_list_last_separator_lang_tl ,
+  list-last-sep      .tl_set:N   = \l__chemnum_list_last_separator_tl ,
+  list-last-sep      .default:n  = \l__chemnum_list_last_separator_lang_tl ,
   list-serial-comma  .choice: ,
   list-serial-comma / true .code:n =
-    \bool_set_false:N \l_chemnum_no_serial_comma_bool ,
+    \bool_set_false:N \l__chemnum_no_serial_comma_bool ,
   list-serial-comma / false .code:n =
-    \bool_set_true:N \l_chemnum_no_serial_comma_bool ,
+    \bool_set_true:N \l__chemnum_no_serial_comma_bool ,
   list-serial-comma  .default:n  = true ,
   list-lang          .choice: ,
   list-lang / US     .code:n     =
     {
-      \bool_set_false:N \l_chemnum_no_serial_comma_bool
-      \tl_set:Nn \l_chemnum_list_last_separator_lang_tl { and }
+      \bool_set_false:N \l__chemnum_no_serial_comma_bool
+      \tl_set:Nn \l__chemnum_list_last_separator_lang_tl { and }
     } ,
   list-lang / GB     .code:n     =
     {
-      \bool_set_true:N \l_chemnum_no_serial_comma_bool
-      \tl_set:Nn \l_chemnum_list_last_separator_lang_tl { and }
+      \bool_set_true:N \l__chemnum_no_serial_comma_bool
+      \tl_set:Nn \l__chemnum_list_last_separator_lang_tl { and }
     } ,
   list-lang / DE     .code:n     =
     {
-      \bool_set_true:N \l_chemnum_no_serial_comma_bool
-      \tl_set:Nn \l_chemnum_list_last_separator_lang_tl { und }
+      \bool_set_true:N \l__chemnum_no_serial_comma_bool
+      \tl_set:Nn \l__chemnum_list_last_separator_lang_tl { und }
     } ,
   list-lang / FR     .code:n     =
     {
-      \bool_set_true:N \l_chemnum_no_serial_comma_bool
-      \tl_set:Nn \l_chemnum_list_last_separator_lang_tl { et }
+      \bool_set_true:N \l__chemnum_no_serial_comma_bool
+      \tl_set:Nn \l__chemnum_list_last_separator_lang_tl { et }
     } ,
   list-lang / IT     .code:n     =
     {
-      \bool_set_true:N \l_chemnum_no_serial_comma_bool
-      \tl_set:Nn \l_chemnum_list_last_separator_lang_tl { e }
+      \bool_set_true:N \l__chemnum_no_serial_comma_bool
+      \tl_set:Nn \l__chemnum_list_last_separator_lang_tl { e }
     } ,
   list-lang / ES     .code:n     =
     {
-      \bool_set_true:N \l_chemnum_no_serial_comma_bool
-      \tl_set:Nn \l_chemnum_list_last_separator_lang_tl { y }
+      \bool_set_true:N \l__chemnum_no_serial_comma_bool
+      \tl_set:Nn \l__chemnum_list_last_separator_lang_tl { y }
     } ,
   list-lang          .default:n  = US
 }
 
 %-----------------------------------------------------------------------------%
 % label and sublabel declaration
-\cs_new:Npn \chemnum_cmpd_declare:n #1
+\cs_new:Npn \__chemnum_cmpd_declare:n #1
   {
     \cs_if_exist:cF { chemnum_cmpd_#1: }
       {
-        \int_gincr:N \g_chemnum_cmpd_main_int
-        \prop_gput:Nnx \g_chemnum_label_prop
+        \int_gincr:N \g__chemnum_cmpd_main_int
+        \prop_gput:Nnx \g__chemnum_label_prop
           { #1 }
-          { \int_use:N \g_chemnum_cmpd_main_int }
-        \chemnum_cmpd_save:n { #1 }
-        \bool_if:NF \l_chemnum_cmpd_name_bool
-          { \int_gincr:N \g_chemnum_cmpd_int }
+          { \int_use:N \g__chemnum_cmpd_main_int }
+        \__chemnum_cmpd_save:n { #1 }
+        \bool_if:NF \l__chemnum_cmpd_name_bool
+          { \int_gincr:N \g__chemnum_cmpd_int }
         \cs_new_nopar:cpx { chemnum_cmpd_#1: } {
-          \bool_if:NTF \l_chemnum_cmpd_name_bool
-            { \l_chemnum_cmpd_name_tl }
+          \bool_if:NTF \l__chemnum_cmpd_name_bool
+            { \l__chemnum_cmpd_name_tl }
             {
-              \chemnum_cmpd_kind:nn
-                \l_chemnum_cmpd_kind_value_tl
-                \g_chemnum_cmpd_int
+              \__chemnum_cmpd_kind:nn
+                \l__chemnum_cmpd_kind_value_tl
+                \g__chemnum_cmpd_int
             }
         }
       }
   }
 
-\cs_new:Npn \chemnum_cmpd_sub_declare:nn #1#2
+\cs_new:Npn \__chemnum_cmpd_sub_declare:nn #1#2
   {
     \cs_if_exist:cF { chemnum_cmpd_#1_#2: }
       {
-        \chemnum_cmpd_save:n { #1 _ #2 }
+        \__chemnum_cmpd_save:n { #1 _ #2 }
         \cs_new_nopar:cpx { chemnum_cmpd_#1_#2: } { }
         \int_gincr:c { g_chemnum_cmpd_#1_int }
         % why is the next line working when \cs_gset_nopar:cpx doesn't?
         % (in case ":" is part of #1)
         \exp_after:wN \cs_gset_nopar:Npx \cs:w chemnum_cmpd_#1_#2: \cs_end:
           {
-            \chemnum_cmpd_sub_kind:Nc
-              \l_chemnum_cmpd_sub_kind_value_tl
+            \__chemnum_cmpd_sub_kind:Nc
+              \l__chemnum_cmpd_sub_kind_value_tl
               { g_chemnum_cmpd_#1_int }
           }
         \int_compare:nT { \int_use:c { g_chemnum_cmpd_#1_int } = 1 }
@@ -877,47 +862,47 @@
         \cs_gset_eq:cc { chemnum_cmpd_#1_max: } { chemnum_cmpd_#1_#2: }
       }
   }
-\cs_generate_variant:Nn \chemnum_cmpd_sub_declare:nn { no }
+\cs_generate_variant:Nn \__chemnum_cmpd_sub_declare:nn { no }
 
-\cs_new_nopar:Npn \chemnum_cmpd_sub_initiate:nn #1#2
+\cs_new_nopar:Npn \__chemnum_cmpd_sub_initiate:nn #1#2
   {
     \cs_if_exist:cF { chemnum_cmpd_ #1 _ #2 _init: }
       {
-        \bool_if:NTF \l_chemnum_cmpd_init_strict_bool
+        \bool_if:NTF \l__chemnum_cmpd_init_strict_bool
           {
             \msg_error:nnx   { chemnum } { cmpd-init-sub }
-              { #1 \l_chemnum_cmpd_labelsep_tl #2 }
+              { #1 \l__chemnum_cmpd_labelsep_tl #2 }
           }
           {
             \msg_warning:nnx { chemnum } { cmpd-init-sub }
-               { #1 \l_chemnum_cmpd_labelsep_tl #2 }
+               { #1 \l__chemnum_cmpd_labelsep_tl #2 }
           }
       }
   }
 
 %-----------------------------------------------------------------------------%
 % label and sublabel initiation
-\cs_new:Npn \chemnum_cmpd_initiate:nn #1#2
+\cs_new:Npn \__chemnum_cmpd_initiate:nn #1#2
   {
     \cs_if_exist:cTF { chemnum_cmpd_#1_init: }
       {
-        \bool_if:NT \l_chemnum_cmpd_sub_init_bool
+        \bool_if:NT \l__chemnum_cmpd_sub_init_bool
           {
             \tl_if_blank:nF { #2 }
               {
-                \chemnum_cmpd_sublist:n { #2 }
-                \exp_args:No \tl_map_inline:nn  { \l_chemnum_cmpd_sublist_tl }
+                \__chemnum_cmpd_sublist:n { #2 }
+                \exp_args:No \tl_map_inline:nn  { \l__chemnum_cmpd_sublist_tl }
                   {
-                    \chemnum_cmpd_subrange_separate:n { ##1 }
-                    \chemnum_cmpd_sub_initiate:nn { #1 } { \l_tmpa_tl }
+                    \__chemnum_cmpd_subrange_separate:n { ##1 }
+                    \__chemnum_cmpd_sub_initiate:nn { #1 } { \l_tmpa_tl }
                     \tl_if_blank:VF \l_tmpb_tl
-                      { \chemnum_cmpd_sub_initiate:nn { #1 } { \l_tmpb_tl } }
+                      { \__chemnum_cmpd_sub_initiate:nn { #1 } { \l_tmpb_tl } }
                   }
               }
           }
       }
       {
-        \bool_if:NTF \l_chemnum_cmpd_init_strict_bool
+        \bool_if:NTF \l__chemnum_cmpd_init_strict_bool
           { \msg_error:nnx { chemnum } { cmpd-init } { #1 } }
           { \msg_warning:nnx { chemnum } { cmpd-init } { #1 } }
       }
@@ -940,79 +925,78 @@
 %-----------------------------------------------------------------------------%
 % variables
 
-\tl_new:N \l_chemnum_cmpd_main_label_tl
-\tl_new:N \l_chemnum_cmpd_sub_label_tl
-
-\tl_new:N \l_chemnum_labelsep_tmp_tl
+\tl_new:N \l__chemnum_cmpd_main_label_tl
+\tl_new:N \l__chemnum_cmpd_sub_label_tl
+\tl_new:N \l__chemnum_labelsep_tmp_tl
 
 % set sublabel-separator
-\cs_new_nopar:Npn \chemnum_subcmpdsep:n #1 {
+\cs_new_nopar:Npn \__chemnum_subcmpdsep:n #1 {
   \tl_if_blank:nTF { #1 }
     { \msg_error:nn { chemnum } { sub-label-separator } }
-    { \tl_set:Nn \l_chemnum_cmpd_labelsep_tl { #1 } }
+    { \tl_set:Nn \l__chemnum_cmpd_labelsep_tl { #1 } }
 }
 
-\cs_new_nopar:Npn \chemnum_sublabel_range_marker:n #1 {
+\cs_new_nopar:Npn \__chemnum_sublabel_range_marker:n #1 {
   \tl_if_blank:nTF { #1 }
     { \msg_error:nn { chemnum } { sub-label-range_sep } }
-    { \tl_set:Nn \l_chemnum_sublabel_range_marker_tl { #1 } }
+    { \tl_set:Nn \l__chemnum_sublabel_range_marker_tl { #1 } }
 }
 
 % actual separating
-\cs_new_nopar:Npn \chemnum_cmpd_labelsep:n #1 \q_stop {
-  \tl_clear:N \l_chemnum_labelsep_tmp_tl
-  \exp_args:Noo \tl_if_in:nnTF { #1 } { \l_chemnum_cmpd_labelsep_tl }
+\cs_new_nopar:Npn \__chemnum_cmpd_labelsep:n #1 \q_stop {
+  \tl_clear:N \l__chemnum_labelsep_tmp_tl
+  \exp_args:Noo \tl_if_in:nnTF { #1 } { \l__chemnum_cmpd_labelsep_tl }
     { 
-      \tl_set:Nn \l_chemnum_labelsep_tmp_tl { #1 }
-      \exp_args:NNo \tl_replace_once:Nnn \l_chemnum_labelsep_tmp_tl
-        { \l_chemnum_cmpd_labelsep_tl }
+      \tl_set:Nn \l__chemnum_labelsep_tmp_tl { #1 }
+      \exp_args:NNo \tl_replace_once:Nnn \l__chemnum_labelsep_tmp_tl
+        { \l__chemnum_cmpd_labelsep_tl }
         { \q_nil }
-      \exp_after:wN \chemnum_cmpd_labelsep_aux_ii:n
-        \l_chemnum_labelsep_tmp_tl \q_stop
+      \exp_after:wN \__chemnum_cmpd_labelsep_aux_ii:n
+        \l__chemnum_labelsep_tmp_tl \q_stop
     }
-    { \chemnum_cmpd_labelsep_aux_i:n { #1 } }
+    { \__chemnum_cmpd_labelsep_aux_i:n { #1 } }
 }
 
-\cs_new_nopar:Npn \chemnum_cmpd_labelsep_aux_i:n #1
+\cs_new_nopar:Npn \__chemnum_cmpd_labelsep_aux_i:n #1
   {
-    \tl_set:Nn \l_chemnum_cmpd_main_label_tl { #1 }
-    \tl_clear:N \l_chemnum_cmpd_sub_label_tl
+    \tl_set:Nn \l__chemnum_cmpd_main_label_tl { #1 }
+    \tl_clear:N \l__chemnum_cmpd_sub_label_tl
   }
 
-\cs_new_nopar:Npn \chemnum_cmpd_labelsep_aux_ii:n #1 \q_nil #2 \q_stop
+\cs_new_nopar:Npn \__chemnum_cmpd_labelsep_aux_ii:n #1 \q_nil #2 \q_stop
   {
-    \tl_set:Nn \l_chemnum_cmpd_main_label_tl { #1 }
-    \tl_set:Nn \l_chemnum_cmpd_sub_label_tl { #2 }
+    \tl_set:Nn \l__chemnum_cmpd_main_label_tl { #1 }
+    \tl_set:Nn \l__chemnum_cmpd_sub_label_tl { #2 }
   }
 
 % sublabel separating to display a list and/or range
-\tl_new:N \l_chemnum_cmpd_sublist_tl
-\int_new:N \l_chemnum_cmpd_sublist_length_int
+\tl_new:N \l__chemnum_cmpd_sublist_tl
+\int_new:N \l__chemnum_cmpd_sublist_length_int
 
-\NewDocumentCommand \chemnum_cmpd_sublist:n
-  { > { \exp_args:No \SplitList { \l_chemnum_sublist_input_separator_tl } } m }
+\NewDocumentCommand \__chemnum_cmpd_sublist:n
+  { > { \exp_args:No \SplitList { \l__chemnum_sublist_input_separator_tl } } m }
   {
-    \tl_set:Nn \l_chemnum_cmpd_sublist_tl { #1 }
-    \int_zero:N \l_chemnum_cmpd_sublist_length_int
-    \exp_args:No \tl_map_inline:nn { \l_chemnum_cmpd_sublist_tl }
-      { \int_incr:N \l_chemnum_cmpd_sublist_length_int }
+    \tl_set:Nn \l__chemnum_cmpd_sublist_tl { #1 }
+    \int_zero:N \l__chemnum_cmpd_sublist_length_int
+    \exp_args:No \tl_map_inline:nn { \l__chemnum_cmpd_sublist_tl }
+      { \int_incr:N \l__chemnum_cmpd_sublist_length_int }
   }
 
-\cs_new_nopar:Npn \chemnum_cmpd_subrange_separate:n #1
+\cs_new_nopar:Npn \__chemnum_cmpd_subrange_separate:n #1
   {
     \tl_clear:N \l_tmpa_tl
     \tl_clear:N \l_tmpb_tl
-    \tl_if_in:noTF { #1 } { \l_chemnum_sublabel_range_marker_tl }
+    \tl_if_in:noTF { #1 } { \l__chemnum_sublabel_range_marker_tl }
       {
         \tl_set:Nn \l_tmpa_tl { #1 }
         \exp_args:NNo \tl_replace_once:Nnn \l_tmpa_tl
-          { \l_chemnum_sublabel_range_marker_tl } { \q_nil }
-        \exp_after:wN \chemnum_cmpd_subrange_separate_aux:n \l_tmpa_tl \q_stop
+          { \l__chemnum_sublabel_range_marker_tl } { \q_nil }
+        \exp_after:wN \__chemnum_cmpd_subrange_separate_aux:n \l_tmpa_tl \q_stop
       }
       { \tl_set:Nn \l_tmpa_tl { #1 } }
   }
 
-\cs_new_nopar:Npn \chemnum_cmpd_subrange_separate_aux:n
+\cs_new_nopar:Npn \__chemnum_cmpd_subrange_separate_aux:n
   #1 \q_nil #2 \q_stop
   {
     \tl_set:Nn \l_tmpa_tl { #1 }
@@ -1021,20 +1005,20 @@
 
 %-----------------------------------------------------------------------------%
 % print compound label
-\cs_new_nopar:Npn \chemnum_cmpd_print:n #1
+\cs_new_nopar:Npn \__chemnum_cmpd_print:n #1
   {
-    \tl_if_blank:VF \l_chemnum_cmpd_prefix_tl
+    \tl_if_blank:VF \l__chemnum_cmpd_prefix_tl
       {
-        \tl_use:N \l_chemnum_cmpd_prefix_tl
-        \tl_use:N \l_chemnum_cmpd_space_tl
+        \tl_use:N \l__chemnum_cmpd_prefix_tl
+        \tl_use:N \l__chemnum_cmpd_space_tl
       }
-    \tl_use:N \l_chemnum_cmpd_odelim_tl
-    \chemnum_cmpd_use_style:n { #1 }
-    \tl_use:N \l_chemnum_cmpd_cdelim_tl
-    \tl_if_blank:VF \l_chemnum_cmpd_suffix_tl
+    \tl_use:N \l__chemnum_cmpd_odelim_tl
+    \__chemnum_cmpd_use_style:n { #1 }
+    \tl_use:N \l__chemnum_cmpd_cdelim_tl
+    \tl_if_blank:VF \l__chemnum_cmpd_suffix_tl
       {
-        \tl_use:N \l_chemnum_cmpd_space_tl
-        \tl_use:N \l_chemnum_cmpd_suffix_tl
+        \tl_use:N \l__chemnum_cmpd_space_tl
+        \tl_use:N \l__chemnum_cmpd_suffix_tl
       }
   }
 
@@ -1042,26 +1026,26 @@
 % main internal compound label command
 % #1: <main label> #2: <sub label> #3: <invisible> #4: <no delim>
 % #2 may be a list of sublabels
-\cs_new_nopar:Npn \chemnum_cmpd_aux_i:nnnn #1#2#3#4
+\cs_new_nopar:Npn \__chemnum_cmpd_aux_i:nnnn #1#2#3#4
   {
-    \bool_if:NT \l_chemnum_cmpd_initiated_bool
-      { \chemnum_cmpd_initiate:nn { #1 } { #2 } }
-    \bool_if:NF \l_chemnum_cmpd_ref_bool
-      { \chemnum_cmpd_declare:n { #1 } }
-    \chemnum_hyperref:nnn { #1 } { #2 } { #3 }
+    \bool_if:NT \l__chemnum_cmpd_initiated_bool
+      { \__chemnum_cmpd_initiate:nn { #1 } { #2 } }
+    \bool_if:NF \l__chemnum_cmpd_ref_bool
+      { \__chemnum_cmpd_declare:n { #1 } }
+    \__chemnum_hyperref:nnn { #1 } { #2 } { #3 }
     \tl_if_blank:nF { #2 }
       {
         \cs_if_exist:cF { g_chemnum_cmpd_#1_int }
           { \int_new:c { g_chemnum_cmpd_#1_int } }
-        \chemnum_cmpd_sublist:n { #2 }
-        \bool_if:NF \l_chemnum_cmpd_ref_bool
+        \__chemnum_cmpd_sublist:n { #2 }
+        \bool_if:NF \l__chemnum_cmpd_ref_bool
           {
-            \exp_args:No \tl_map_inline:nn { \l_chemnum_cmpd_sublist_tl }
+            \exp_args:No \tl_map_inline:nn { \l__chemnum_cmpd_sublist_tl }
               {
-                \chemnum_cmpd_subrange_separate:n { ##1 }
-                \chemnum_cmpd_sub_declare:no { #1 } { \l_tmpa_tl }
+                \__chemnum_cmpd_subrange_separate:n { ##1 }
+                \__chemnum_cmpd_sub_declare:no { #1 } { \l_tmpa_tl }
                 \tl_if_blank:VF \l_tmpb_tl
-                  { \chemnum_cmpd_sub_declare:no { #1 } { \l_tmpb_tl } }
+                  { \__chemnum_cmpd_sub_declare:no { #1 } { \l_tmpb_tl } }
               }
           }
       }
@@ -1070,60 +1054,60 @@
       { 
         \bool_if:NT #4
           {
-            \tl_clear:N \l_chemnum_cmpd_odelim_tl
-            \tl_clear:N \l_chemnum_cmpd_cdelim_tl
+            \tl_clear:N \l__chemnum_cmpd_odelim_tl
+            \tl_clear:N \l__chemnum_cmpd_cdelim_tl
           }
-        \chemnum_make_hyper:nn { \l_chemnum_cmpd_hyper_name_tl }
+        \__chemnum_make_hyper:nn { \l__chemnum_cmpd_hyper_name_tl }
         {
-        \chemnum_cmpd_print:n
+        \__chemnum_cmpd_print:n
           {
-            \bool_if:NF \l_chemnum_sub_label_only_bool
+            \bool_if:NF \l__chemnum_sub_label_only_bool
               {
-                \bool_if:NTF \l_chemnum_cmpd_ref_bool
+                \bool_if:NTF \l__chemnum_cmpd_ref_bool
                   { \use:c { chemnum_cmpd_ #1 _ref: } }
                   { \use:c { chemnum_cmpd_ #1 : } }
               }
-            \bool_if:NTF \l_chemnum_cmpd_all_bool
+            \bool_if:NTF \l__chemnum_cmpd_all_bool
               {
-                \tl_use:N \l_chemnum_cmpd_separator_tl
+                \tl_use:N \l__chemnum_cmpd_separator_tl
                 \use:c { chemnum_cmpd_ #1 _min_ref: }
                 \cs_if_eq:ccF
                   { chemnum_cmpd_ #1 _min_ref: }
                   { chemnum_cmpd_ #1 _max_ref: }
                   {
-                    \tl_use:N \l_chemnum_sub_range_sep_tl
+                    \tl_use:N \l__chemnum_sub_range_sep_tl
                     \use:c { chemnum_cmpd_ #1 _max_ref: }
                   }
               }
               {
-                \bool_if:NTF \l_chemnum_sublabel_list_bool
+                \bool_if:NTF \l__chemnum_sublabel_list_bool
                   {
-                    \chemnum_cmpd_sublabel_list:nn { #1 }
-                      { \l_chemnum_cmpd_sublabel_list_tl }
+                    \__chemnum_cmpd_sublabel_list:nn { #1 }
+                      { \l__chemnum_cmpd_sublabel_list_tl }
                   }
                   {
                     \tl_if_blank:nF { #2 }
                       {
-                        \tl_use:N \l_chemnum_cmpd_separator_tl
+                        \tl_use:N \l__chemnum_cmpd_separator_tl
                         \int_zero:N \l_tmpa_int
                         \exp_args:No \tl_map_inline:nn
-                          { \l_chemnum_cmpd_sublist_tl }
+                          { \l__chemnum_cmpd_sublist_tl }
                           {
                             \int_incr:N \l_tmpa_int
-                            \chemnum_cmpd_subrange_separate:n { ##1 }
-                            \bool_if:NTF \l_chemnum_cmpd_ref_bool
+                            \__chemnum_cmpd_subrange_separate:n { ##1 }
+                            \bool_if:NTF \l__chemnum_cmpd_ref_bool
                               { \use:c { chemnum_cmpd_ #1 _ \l_tmpa_tl _ref: } }
                               { \use:c { chemnum_cmpd_ #1 _ \l_tmpa_tl : } }
                             \tl_if_blank:VF \l_tmpb_tl
                               {
-                                \tl_use:N \l_chemnum_sub_range_sep_tl
-                                \bool_if:NTF \l_chemnum_cmpd_ref_bool
+                                \tl_use:N \l__chemnum_sub_range_sep_tl
+                                \bool_if:NTF \l__chemnum_cmpd_ref_bool
                                   { \use:c { chemnum_cmpd_ #1 _ \l_tmpb_tl _ref: } }
                                   { \use:c { chemnum_cmpd_ #1 _ \l_tmpb_tl : } }
                               }
                             \int_compare:nF
-                              { \l_tmpa_int = \l_chemnum_cmpd_sublist_length_int }
-                              { \l_chemnum_sublist_output_separator_tl }
+                              { \l_tmpa_int = \l__chemnum_cmpd_sublist_length_int }
+                              { \l__chemnum_sublist_output_separator_tl }
                           }
                       }
                   }
@@ -1132,37 +1116,37 @@
       }
   }
 
-\cs_generate_variant:Nn \chemnum_cmpd_aux_i:nnnn { oonn }
+\cs_generate_variant:Nn \__chemnum_cmpd_aux_i:nnnn { oonn }
 
 %-----------------------------------------------------------------------------%
 % create compound label
 % #1: label name #2: star (invisible) #3: minus (no delimiters)
-\cs_new_nopar:Npn \chemnum_cmpd:nnn #1#2#3 {
+\cs_new_nopar:Npn \__chemnum_cmpd:nnn #1#2#3 {
   \group_begin:
-    \tl_clear:N \l_chemnum_cmpd_main_label_tl
-    \tl_clear:N \l_chemnum_cmpd_sub_label_tl
-    \chemnum_cmpd_labelsep:n #1 \q_stop
-    \tl_remove_all:Nn \l_chemnum_cmpd_sub_label_tl { ~ }
-    \chemnum_cmpd_aux_i:oonn
-      { \l_chemnum_cmpd_main_label_tl }
-      { \l_chemnum_cmpd_sub_label_tl }
+    \tl_clear:N \l__chemnum_cmpd_main_label_tl
+    \tl_clear:N \l__chemnum_cmpd_sub_label_tl
+    \__chemnum_cmpd_labelsep:n #1 \q_stop
+    \tl_remove_all:Nn \l__chemnum_cmpd_sub_label_tl { ~ }
+    \__chemnum_cmpd_aux_i:oonn
+      { \l__chemnum_cmpd_main_label_tl }
+      { \l__chemnum_cmpd_sub_label_tl }
       { #2 }
       { #3 }
   \group_end:
 }
 
-\cs_generate_variant:Nn \chemnum_cmpd:nnn { onn }
+\cs_generate_variant:Nn \__chemnum_cmpd:nnn { onn }
 
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % DOCUMENT COMMANDS
 % variables:
-\int_new:N \l_chemnum_list_items_int
-\int_new:N \l_chemnum_list_separate_int
+\int_new:N \l__chemnum_list_items_int
+\int_new:N \l__chemnum_list_separate_int
 
-\tl_new:N \l_chemnum_list_last_sep_empty_tl
-\tl_set:Nn \l_chemnum_list_last_sep_empty_tl { empty }
+\tl_new:N  \l__chemnum_list_last_sep_empty_tl
+\tl_set:Nn \l__chemnum_list_last_sep_empty_tl { empty }
 
-\bool_new:N \l_chemnum_cmpd_ref_bool
+\bool_new:N \l__chemnum_cmpd_ref_bool
 
 \msg_set:nnnn { chemnum } { fatal-combination }
   {
@@ -1179,52 +1163,55 @@
 % MAIN COMMAND
 % \cmpd*+-[<key-value-list>]{<(possibly comma separated list of) compound
 % label(s)>}
-\NewDocumentCommand \chemnum_input_separator:n
-  { > { \exp_args:No \SplitList { \l_chemnum_list_input_separator_tl } } m }
+\NewDocumentCommand \__chemnum_input_separator:n
+  { > { \exp_args:No \SplitList { \l__chemnum_list_input_separator_tl } } m }
   { \tl_set:Nn \l_tmpa_tl { #1 } }
 
-\NewDocumentCommand \cmpd_main_command:w { s t+ t- o m }
+\NewDocumentCommand \cmpd { s t+ t- o m }
+  { \cmpd_main:nnnnn { #1 } { #2 } { #3 } { #4 } { #5 } }
+
+\cs_new:Npn \cmpd_main:nnnnn #1#2#3#4#5
   {
     \IfBooleanT #2
       {
-        \bool_set_true:N \l_chemnum_cmpd_ref_bool
+        \bool_set_true:N \l__chemnum_cmpd_ref_bool
         \IfBooleanT #1
           { \msg_error:nnx { chemnum } { fatal-combination } { plus } }
       }
-    \tl_clear:N \l_chemnum_tmpa_tl
+    \tl_clear:N \l__chemnum_tmpa_tl
     \group_begin:
-      \int_zero:N \l_chemnum_list_items_int
-      \int_zero:N \l_chemnum_list_separate_int
+      \int_zero:N \l__chemnum_list_items_int
+      \int_zero:N \l__chemnum_list_separate_int
       \IfNoValueF { #4 }
         { \keys_set:nn { chemnum } { #4 } }
-      \chemnum_input_separator:n { #5 }
-      \tl_map_variable:NNn \l_tmpa_tl \l_chemnum_tmpa_tl
+      \__chemnum_input_separator:n { #5 }
+      \tl_map_variable:NNn \l_tmpa_tl \l__chemnum_tmpa_tl
         {
-          \tl_if_blank:VF \l_chemnum_tmpa_tl
-            { \int_incr:N \l_chemnum_list_items_int }
+          \tl_if_blank:VF \l__chemnum_tmpa_tl
+            { \int_incr:N \l__chemnum_list_items_int }
         }
-      \tl_map_variable:NNn \l_tmpa_tl \l_chemnum_tmpa_tl
+      \tl_map_variable:NNn \l_tmpa_tl \l__chemnum_tmpa_tl
         {
-          \tl_remove_all:Nn \l_chemnum_tmpa_tl { ~ }
-          \tl_if_blank:VF \l_chemnum_tmpa_tl
+          \tl_remove_all:Nn \l__chemnum_tmpa_tl { ~ }
+          \tl_if_blank:VF \l__chemnum_tmpa_tl
             {
-              \int_incr:N \l_chemnum_list_separate_int
+              \int_incr:N \l__chemnum_list_separate_int
               \IfBooleanF #1
                 {
-                  \if_int_compare:w \l_chemnum_list_separate_int = 1
-                    \if_int_compare:w \l_chemnum_list_items_int = 1
+                  \if_int_compare:w \l__chemnum_list_separate_int = 1
+                    \if_int_compare:w \l__chemnum_list_items_int = 1
                     \else:
-                      \tl_use:N \l_chemnum_list_prefix_tl
-                      \tl_if_blank:VF { \l_chemnum_list_prefix_tl }
-                        { \l_chemnum_list_space_tl }
-                      \tl_use:N \l_chemnum_list_odelim_tl
+                      \tl_use:N \l__chemnum_list_prefix_tl
+                      \tl_if_blank:VF { \l__chemnum_list_prefix_tl }
+                        { \l__chemnum_list_space_tl }
+                      \tl_use:N \l__chemnum_list_odelim_tl
                     \fi:
                   \fi:
                 }
               \IfBooleanTF #1
                 {
-                  \chemnum_cmpd:onn
-                    { \l_chemnum_tmpa_tl }
+                  \__chemnum_cmpd:onn
+                    { \l__chemnum_tmpa_tl }
                     { \BooleanTrue }
                     { \BooleanFalse }
                   \IfBooleanT #3
@@ -1236,89 +1223,87 @@
                 { 
                   \IfBooleanTF #3
                     {
-                      \chemnum_cmpd:onn
-                        { \l_chemnum_tmpa_tl }
+                      \__chemnum_cmpd:onn
+                        { \l__chemnum_tmpa_tl }
                         { \BooleanFalse }
                         { \BooleanTrue }
                     }
                     {
-                      \chemnum_cmpd:onn
-                        { \l_chemnum_tmpa_tl }
+                      \__chemnum_cmpd:onn
+                        { \l__chemnum_tmpa_tl }
                         { \BooleanFalse }
                         { \BooleanFalse }
                     }
                   \int_compare:nTF
-                    { \l_chemnum_list_separate_int = \l_chemnum_list_items_int }
+                    { \l__chemnum_list_separate_int = \l__chemnum_list_items_int }
                     {
-                      \int_compare:nNnF { \l_chemnum_list_items_int } = { 1 }
+                      \int_compare:nNnF { \l__chemnum_list_items_int } = { 1 }
                         {
-                          \tl_use:N \l_chemnum_list_cdelim_tl
+                          \tl_use:N \l__chemnum_list_cdelim_tl
                           \tl_if_blank:VF
-                            { \l_chemnum_list_suffix_tl }
-                            { \l_chemnum_list_space_tl }
-                          \tl_use:N \l_chemnum_list_suffix_tl
+                            { \l__chemnum_list_suffix_tl }
+                            { \l__chemnum_list_space_tl }
+                          \tl_use:N \l__chemnum_list_suffix_tl
                         }
                     }
                     {
                       \int_compare:nTF
                         {
-                          \l_chemnum_list_separate_int
+                          \l__chemnum_list_separate_int
                           =
-                          \int_eval:n { \l_chemnum_list_items_int - 1 }
+                          \int_eval:n { \l__chemnum_list_items_int - 1 }
                         }
                         {
                           \tl_if_eq:NNTF
-                            \l_chemnum_list_last_separator_tl
-                            \l_chemnum_list_last_sep_empty_tl
+                            \l__chemnum_list_last_separator_tl
+                            \l__chemnum_list_last_sep_empty_tl
                             {
-                              \tl_use:N \l_chemnum_list_separator_tl
-                              \l_chemnum_list_space_tl
+                              \tl_use:N \l__chemnum_list_separator_tl
+                              \l__chemnum_list_space_tl
                             }
                             {
                               \int_compare:nNnF
-                                { \l_chemnum_list_separate_int } = { 1 }
+                                { \l__chemnum_list_separate_int } = { 1 }
                                 {
-                                  \bool_if:NF \l_chemnum_no_serial_comma_bool
-                                    { \l_chemnum_list_separator_tl }
+                                  \bool_if:NF \l__chemnum_no_serial_comma_bool
+                                    { \l__chemnum_list_separator_tl }
                                 }
-                              \tl_if_blank:VF \l_chemnum_list_last_separator_tl
-                                { \l_chemnum_list_space_tl }
-                              \tl_use:N \l_chemnum_list_last_separator_tl
-                              \l_chemnum_list_space_tl
+                              \tl_if_blank:VF \l__chemnum_list_last_separator_tl
+                                { \l__chemnum_list_space_tl }
+                              \tl_use:N \l__chemnum_list_last_separator_tl
+                              \l__chemnum_list_space_tl
                             }
                         }
                         {
-                          \tl_use:N \l_chemnum_list_separator_tl
-                          \l_chemnum_list_space_tl
+                          \tl_use:N \l__chemnum_list_separator_tl
+                          \l__chemnum_list_space_tl
                         }
                   }
                 }
             }
         }
     \group_end:
-    \bool_set_false:N \l_chemnum_cmpd_ref_bool
+    \bool_set_false:N \l__chemnum_cmpd_ref_bool
   }
 
-\cs_set_eq:NN \cmpd \cmpd_main_command:w
-
 %-----------------------------------------------------------------------------%
 % INITIALISING LABELS
-\bool_new:N \l_chemnum_cmpd_initiated_bool
-\bool_new:N \l_chemnum_cmpd_init_strict_bool
-\bool_new:N \l_chemnum_cmpd_sub_init_bool
-\bool_new:N \l_chemnum_cmpd_init_declare_bool
+\bool_new:N \l__chemnum_cmpd_initiated_bool
+\bool_new:N \l__chemnum_cmpd_init_strict_bool
+\bool_new:N \l__chemnum_cmpd_sub_init_bool
+\bool_new:N \l__chemnum_cmpd_init_declare_bool
 
-\tl_new:N \l_chemnum_cmpd_init_separator_tl
-\tl_set:Nn \l_chemnum_cmpd_init_separator_tl { , }
+\tl_new:N  \l__chemnum_cmpd_init_separator_tl
+\tl_set:Nn \l__chemnum_cmpd_init_separator_tl { , }
 
 % property keys for \cmpdinit command
 % strict=true will produce an error instead of a warning
 \keys_define:nn { chemnum } {
-  init-strict    .bool_set:N = \l_chemnum_cmpd_init_strict_bool ,
+  init-strict    .bool_set:N = \l__chemnum_cmpd_init_strict_bool ,
   init-strict    .default:n  = true ,
-  init-sub       .bool_set:N = \l_chemnum_cmpd_sub_init_bool ,
+  init-sub       .bool_set:N = \l__chemnum_cmpd_sub_init_bool ,
   init-sub       .default:n  = true ,
-  init-input-sep .tl_set:N   = \l_chemnum_cmpd_init_separator_tl ,
+  init-input-sep .tl_set:N   = \l__chemnum_cmpd_init_separator_tl ,
   init-input-sep .default:n  = { , }
 }
 
@@ -1336,32 +1321,32 @@
   }
 
 % initialize (and maybe declare) labels
-\cs_new_nopar:Npn \chemnum_cmpd_init:n #1
+\cs_new_nopar:Npn \__chemnum_cmpd_init:n #1
   {
-    \tl_clear:N \l_chemnum_tmpa_tl
-    \tl_set:Nn \l_chemnum_tmpa_tl { #1 }
-    \tl_remove_all:Nn \l_chemnum_tmpa_tl { ~ }
-    \tl_clear:N \l_chemnum_cmpd_main_label_tl
-    \tl_clear:N \l_chemnum_cmpd_sub_label_tl
-    \exp_after:wN \chemnum_cmpd_labelsep:n \l_chemnum_tmpa_tl \q_stop
-    \cs_if_exist:cF { chemnum_cmpd_ \l_chemnum_cmpd_main_label_tl  _init: }
+    \tl_clear:N \l__chemnum_tmpa_tl
+    \tl_set:Nn \l__chemnum_tmpa_tl { #1 }
+    \tl_remove_all:Nn \l__chemnum_tmpa_tl { ~ }
+    \tl_clear:N \l__chemnum_cmpd_main_label_tl
+    \tl_clear:N \l__chemnum_cmpd_sub_label_tl
+    \exp_after:wN \__chemnum_cmpd_labelsep:n \l__chemnum_tmpa_tl \q_stop
+    \cs_if_exist:cF { chemnum_cmpd_ \l__chemnum_cmpd_main_label_tl  _init: }
       {
         \cs_new_nopar:cpn
-          { chemnum_cmpd_ \l_chemnum_cmpd_main_label_tl _init: }
+          { chemnum_cmpd_ \l__chemnum_cmpd_main_label_tl _init: }
           { }
       }
-    \bool_if:NT \l_chemnum_cmpd_sub_init_bool
+    \bool_if:NT \l__chemnum_cmpd_sub_init_bool
       {
-        \tl_if_blank:VF \l_chemnum_cmpd_sub_label_tl
+        \tl_if_blank:VF \l__chemnum_cmpd_sub_label_tl
           {
-            \exp_args:No \chemnum_cmpd_sublist:n
-              { \l_chemnum_cmpd_sub_label_tl }
-            \exp_args:No \tl_map_inline:nn { \l_chemnum_cmpd_sublist_tl }
+            \exp_args:No \__chemnum_cmpd_sublist:n
+              { \l__chemnum_cmpd_sub_label_tl }
+            \exp_args:No \tl_map_inline:nn { \l__chemnum_cmpd_sublist_tl }
               {
                 \cs_if_exist:cF
                   {
                     chemnum_cmpd_ 
-                    \l_chemnum_cmpd_main_label_tl
+                    \l__chemnum_cmpd_main_label_tl
                     _
                     ##1
                     _init:
@@ -1370,7 +1355,7 @@
                     \cs_new_nopar:cpn
                       {
                         chemnum_cmpd_
-                        \l_chemnum_cmpd_main_label_tl
+                        \l__chemnum_cmpd_main_label_tl
                         _
                         ##1
                         _init:
@@ -1380,10 +1365,10 @@
               }
           }
       }
-    \bool_if:NT \l_chemnum_cmpd_init_declare_bool
+    \bool_if:NT \l__chemnum_cmpd_init_declare_bool
       {
-        \chemnum_cmpd:onn
-          { \l_chemnum_tmpa_tl }
+        \__chemnum_cmpd:onn
+          { \l__chemnum_tmpa_tl }
           { \BooleanTrue }
           { \BooleanFalse }
       }
@@ -1392,13 +1377,13 @@
 % \cmpdinit*[strict=<bool>]{<comma separated list of label names>}
 \NewDocumentCommand \cmpdinit { s o m }
   {
-    \bool_set_true:N \l_chemnum_cmpd_initiated_bool
+    \bool_set_true:N \l__chemnum_cmpd_initiated_bool
     \IfBooleanTF #1
-      { \bool_set_false:N \l_chemnum_cmpd_init_declare_bool }
-      { \bool_set_true:N \l_chemnum_cmpd_init_declare_bool }
+      { \bool_set_false:N \l__chemnum_cmpd_init_declare_bool }
+      { \bool_set_true:N \l__chemnum_cmpd_init_declare_bool }
     \IfNoValueF { #2 } { \keys_set:nn { chemnum } { #2 } }
-    \chemnum_input_separator:n { #3 }
-    \tl_map_function:NN \l_tmpa_tl \chemnum_cmpd_init:n
+    \__chemnum_input_separator:n { #3 }
+    \tl_map_function:NN \l_tmpa_tl \__chemnum_cmpd_init:n
   }
 
 %-----------------------------------------------------------------------------%
@@ -1407,8 +1392,8 @@
 \NewDocumentCommand \cmpdreset { o }
   {
     \IfNoValueTF { #1 }
-      { \int_zero:N \g_chemnum_cmpd_int }
-      { \int_set:Nn \g_chemnum_cmpd_int { #1 - 1 } }
+      { \int_zero:N \g__chemnum_cmpd_int }
+      { \int_set:Nn \g__chemnum_cmpd_int { #1 - 1 } }
   }
 
 %-----------------------------------------------------------------------------%
@@ -1421,113 +1406,122 @@
 % REPLACE TAG IN EPS PICTURE WITH LABEL
 % works similar to \schemeref command of the chemscheme package
 % \cmpdref-[<keyval>][<tag>]{<label name>}
-\tl_new:N \l_chemnum_cmpdref_tl
-\tl_new:N \l_chemnum_cmpdref_style_tl
-\tl_set:Nn \l_chemnum_cmpdref_style_tl { \sffamily }
-\tl_new:N \l_chemnum_cmpdref_marker_tl
-\tl_set:Nn \l_chemnum_cmpdref_marker_tl { TMP }
-\tl_new:N \l_chemnum_psfrag_texpos_tl
-\tl_new:N \l_chemnum_psfrag_texpos_current_tl
-\tl_set:Nn \l_chemnum_psfrag_texpos_tl { b }
-\tl_new:N \l_chemnum_psfrag_pspos_tl
-\tl_new:N \l_chemnum_psfrag_pspos_current_tl
-\tl_set:Nn \l_chemnum_psfrag_pspos_tl { b }
-
-\int_new:N \l_chemnum_cmpdref_int
-
-\cs_new_nopar:Npn \chemnum_set_psfrag_pos:nn #1#2
+\tl_new:N  \l__chemnum_cmpdref_tl
+\tl_new:N  \l__chemnum_cmpdref_style_tl
+\tl_set:Nn \l__chemnum_cmpdref_style_tl { \sffamily }
+\tl_new:N  \l__chemnum_cmpdref_marker_tl
+\tl_set:Nn \l__chemnum_cmpdref_marker_tl { TMP }
+\tl_new:N  \l__chemnum_psfrag_texpos_tl
+\tl_new:N  \l__chemnum_psfrag_texpos_current_tl
+\tl_set:Nn \l__chemnum_psfrag_texpos_tl { b }
+\tl_new:N  \l__chemnum_psfrag_pspos_tl
+\tl_new:N  \l__chemnum_psfrag_pspos_current_tl
+\tl_set:Nn \l__chemnum_psfrag_pspos_tl { b }
+
+\int_new:N \l__chemnum_cmpdref_int
+
+\cs_new_nopar:Npn \__chemnum_set_psfrag_pos:nn #1#2
   {
-    \tl_set:Nn \l_chemnum_psfrag_texpos_tl { #1 }
-    \tl_set:Nn \l_chemnum_psfrag_pspos_tl { #2 }
+    \tl_set:Nn \l__chemnum_psfrag_texpos_tl { #1 }
+    \tl_set:Nn \l__chemnum_psfrag_pspos_tl { #2 }
   }
 
-\cs_new_nopar:Npn \chemnum_psfrag:nnnn #1#2#3#4
+\cs_new_nopar:Npn \__chemnum_psfrag:nnnn #1#2#3#4
   { \psfrag { #1 } [ #2 ] [ #3 ] { #4 } }
-\cs_generate_variant:Nn \chemnum_psfrag:nnnn { VVVn }
+\cs_generate_variant:Nn \__chemnum_psfrag:nnnn { VVVn }
 
-\cs_new:Npn \chemnum_set_psfrag_pos_local:w #1 ref-pos #2 = #3#4 , #5 \q_stop
+\cs_new:Npn \__chemnum_set_psfrag_pos_local:w #1 ref-pos #2 = #3#4 , #5 \q_stop
   {
-    \tl_set_eq:NN \l_chemnum_psfrag_texpos_current_tl \l_chemnum_psfrag_texpos_tl
-    \tl_set_eq:NN \l_chemnum_psfrag_pspos_current_tl \l_chemnum_psfrag_pspos_tl
-    \tl_set:Nn \l_chemnum_psfrag_texpos_tl { #3 }
-    \tl_set:Nn \l_chemnum_psfrag_pspos_tl { #4 }
+    \tl_set_eq:NN \l__chemnum_psfrag_texpos_current_tl \l__chemnum_psfrag_texpos_tl
+    \tl_set_eq:NN \l__chemnum_psfrag_pspos_current_tl  \l__chemnum_psfrag_pspos_tl
+    \tl_set:Nn \l__chemnum_psfrag_texpos_tl { #3 }
+    \tl_set:Nn \l__chemnum_psfrag_pspos_tl { #4 }
   }
 
 \keys_define:nn { chemnum }
   {
-    ref-tag   .tl_set:N  = \l_chemnum_cmpdref_marker_tl ,
+    ref-tag   .tl_set:N  = \l__chemnum_cmpdref_marker_tl ,
     ref-tag   .default:n = { TMP } ,
-    ref-style .tl_set:N  = \l_chemnum_cmpdref_style_tl ,
+    ref-style .tl_set:N  = \l__chemnum_cmpdref_style_tl ,
     ref-style .default:n = { } ,
-    ref-pos   .code:n    = \chemnum_set_psfrag_pos:nn #1 ,
+    ref-pos   .code:n    = \__chemnum_set_psfrag_pos:nn #1 ,
     ref-pos   .default:n = bb
   }
 
-\NewDocumentCommand \cmpdref { t- o o m }
+\NewDocumentCommand \cmpdref { t- t+ o o m }
+  { \cmpd_ref:nnnnn { #1 } { #2 } { #3 } { #4 } { #5 } }
+
+\cs_new:Npn \cmpd_ref:nnnnn #1#2#3#4#5
   {
       \IfBooleanT { #1 }
         { \keys_set:nn { chemnum } { cmpd-delim = } }
-      \IfNoValueTF { #2 }
+      \IfNoValueTF { #3 }
         {
-          \int_incr:N \l_chemnum_cmpdref_int
-          \tl_set:No \l_chemnum_cmpdref_tl
+          \int_incr:N \l__chemnum_cmpdref_int
+          \tl_set:No \l__chemnum_cmpdref_tl
             {
-              \tl_use:N \l_chemnum_cmpdref_marker_tl
-              \int_use:N \l_chemnum_cmpdref_int
+              \tl_use:N \l__chemnum_cmpdref_marker_tl
+              \int_use:N \l__chemnum_cmpdref_int
             }
         }
         {
-          \tl_if_blank:nTF { #2 }
+          \tl_if_blank:nTF { #3 }
             {
-              \int_incr:N \l_chemnum_cmpdref_int
-              \tl_set:No \l_chemnum_cmpdref_tl
+              \int_incr:N \l__chemnum_cmpdref_int
+              \tl_set:No \l__chemnum_cmpdref_tl
                 {
-                  \tl_use:N \l_chemnum_cmpdref_marker_tl
-                  \int_use:N \l_chemnum_cmpdref_int
+                  \tl_use:N \l__chemnum_cmpdref_marker_tl
+                  \int_use:N \l__chemnum_cmpdref_int
                 }
             }
-            { \tl_set:Nn \l_chemnum_cmpdref_tl { #2 } }
+            { \tl_set:Nn \l__chemnum_cmpdref_tl { #3 } }
         }
-    \IfNoValueTF { #3 }
+    \IfNoValueTF { #4 }
         {
           % need to call it once invisible in case it's the first time the label
           % is called. Somehow it otherwise “vanishes” inside \psfrag
-          \cmpd_main_command:w * { #4 }
-          \chemnum_psfrag:VVVn
-            \l_chemnum_cmpdref_tl
-            \l_chemnum_psfrag_texpos_tl
-            \l_chemnum_psfrag_pspos_tl
+          \IfBooleanF { #2 }
+            { \cmpd * { #5 } }
+          \__chemnum_psfrag:VVVn
+            \l__chemnum_cmpdref_tl
+            \l__chemnum_psfrag_texpos_tl
+            \l__chemnum_psfrag_pspos_tl
             {
               \group_begin:
                 \keys_set:nn { chemnum }
-                  { cmpd-style = \l_chemnum_cmpdref_style_tl }
-                \cmpd_main_command:w { #4 }
+                  { cmpd-style = \l__chemnum_cmpdref_style_tl }
+                \IfBooleanTF { #2 }
+                  { \cmpd + { #5 } }
+                  { \cmpd { #5 } }
               \group_end:
             }
         }
         {
-          % TODO: set psfrag positions before \chemnum_psfrag is called
+          % TODO: set psfrag positions before \__chemnum_psfrag is called
           % ?? hat sich erledigt, oder?
-          \cmpd_main_command:w * [ #3 ] { #4 }
-          \tl_if_in:nnT { #3 } { ref-pos }
-            { \chemnum_set_psfrag_pos_local:w #3 , \q_stop }
-          \chemnum_psfrag:VVVn
-            \l_chemnum_cmpdref_tl
-            \l_chemnum_psfrag_texpos_tl
-            \l_chemnum_psfrag_pspos_tl
+          \IfBooleanF { #2 }
+            { \cmpd * [ #4 ] { #5 } }
+          \tl_if_in:nnT { #4 } { ref-pos }
+            { \__chemnum_set_psfrag_pos_local:w #4 , \q_stop }
+          \__chemnum_psfrag:VVVn
+            \l__chemnum_cmpdref_tl
+            \l__chemnum_psfrag_texpos_tl
+            \l__chemnum_psfrag_pspos_tl
             {
               \group_begin:
                 \keys_set:nn { chemnum }
-                  { cmpd-style = \l_chemnum_cmpdref_style_tl }
-                \cmpd_main_command:w [ #3 ] { #4 }
+                  { cmpd-style = \l__chemnum_cmpdref_style_tl }
+                \IfBooleanTF { #2 }
+                  { \cmpd + [ #4 ] { #5 } }
+                  { \cmpd [ #4 ] { #5 } }
               \group_end:
             }
-          \tl_if_in:nnT { #3 } { ref-pos }
+          \tl_if_in:nnT { #4 } { ref-pos }
             {
               \tl_set_eq:NN
-                \l_chemnum_psfrag_texpos_tl \l_chemnum_psfrag_texpos_current_tl
+                \l__chemnum_psfrag_texpos_tl \l__chemnum_psfrag_texpos_current_tl
               \tl_set_eq:NN
-                \l_chemnum_psfrag_pspos_tl \l_chemnum_psfrag_pspos_current_tl
+                \l__chemnum_psfrag_pspos_tl \l__chemnum_psfrag_pspos_current_tl
             }
         }
   }
@@ -1551,7 +1545,7 @@
 \DeclareTranslation { German  } { and~(list~seperator) } { und }
 \DeclareTranslation { Italian } { and~(list~seperator) } { e }
 \DeclareTranslation { Spanish } { and~(list~seperator) } { y }
-\tl_set:Nn \l_chemnum_list_last_separator_lang_tl
+\tl_set:Nn \l__chemnum_list_last_separator_lang_tl
   { \GetTranslation { and~(list~seperator) } }
 
 \AtBeginDocument
@@ -1559,15 +1553,15 @@
     \@ifpackageloaded { babel }
       {
         \iflanguage { american }
-          { \bool_set_false:N \l_chemnum_no_serial_comma_bool }
-          { \bool_set_true:N \l_chemnum_no_serial_comma_bool }
-        \cs_new_eq:NN \chemnum_selectlanguage:n \selectlanguage
+          { \bool_set_false:N \l__chemnum_no_serial_comma_bool }
+          { \bool_set_true:N  \l__chemnum_no_serial_comma_bool }
+        \cs_new_eq:NN \__chemnum_selectlanguage:n \selectlanguage
         \cs_set_nopar:Npn \selectlanguage #1
           {
-            \chemnum_selectlanguage:n { #1 }
+            \__chemnum_selectlanguage:n { #1 }
             \iflanguage { american }
-              { \bool_set_false:N \l_chemnum_no_serial_comma_bool }
-              { \bool_set_true:N \l_chemnum_no_serial_comma_bool }
+              { \bool_set_false:N \l__chemnum_no_serial_comma_bool }
+              { \bool_set_true:N  \l__chemnum_no_serial_comma_bool }
           }
       }
       {}
@@ -1656,6 +1650,10 @@ HISTORY:
  2012/07/24 version 0.5c - adapted to changes in l3kernel
  2012/08/15 version 0.5d - fixed bug in \cmpdref
  2012/09/17 version 0.5e - fixed bug in \cmpdinit
+ 2012/12/29 version 0.5f - added Italian documentation, minor adjustment of `ref-pos'
+ 2013/01/20 version 0.6  - added + argument to \cmpdref
+                         - changed internal syntax
+
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 % TODO:
  - add a possibility to \ref{} the compounds