%
% ***************** THE SPBMARK PACKAGE *****************
%
% Copyright (C) 2021-2024 by Qu Yi <toquyi@163.com>
%
% This work may be distributed and/or modified under the
% conditions of the CC-BY 4.0 License.
% The latest version of this license is in
%   https://creativecommons.org/licenses/by/4.0/legalcode
\NeedsTeXFormat{LaTeX2e}[2018/12/31]
\RequirePackage{xparse}
\ProvidesExplPackage{spbmark}{2024/10/31}{1.46t}
  {Customize superscripts and subscripts}

\cs_generate_variant:Nn \box_set_ht:Nn { cv }
\cs_generate_variant:Nn \box_set_dp:Nn { cv }
\cs_generate_variant:Nn \dim_max:nn { VV }
\cs_generate_variant:Nn \dim_gset:Nn { Nv }
\cs_generate_variant:Nn \dim_abs:n { V,v }
\cs_generate_variant:Nn \dim_compare:nNnTF { V,v }
\cs_generate_variant:Nn \str_case:nn { x }
\cs_generate_variant:Nn \tl_if_novalue:nF { V }
\cs_generate_variant:Nn \tl_if_blank:nF { v }

\providecommand{\AfterPreamble}{\AtBeginDocument}
\AtBeginDocument{\cs_set_eq:NN \AfterPreamble \use:n}
\cs_set_eq:NN \spb@textsuperscript@save \textsuperscript
\cs_set_eq:NN \spb@textsubscript@save \textsubscript
\cs_set_eq:NN \spb@math@super@save \sp
\cs_set_eq:NN \spb@math@sub@save \sb
\cs_set_eq:NN \spb@@makefnmark@save \@makefnmark
\cs_new_protected:Npn \spb_define:n { \keys_define:nn { ctex/tools } }
\cs_new_protected:Npn \spb_set:n { \keys_set:nn { ctex/tools } }
\cs_set_eq:NN \spbset \spb_set:n
\cs_new_protected:Npn \spb_mark_core_set_trad:n #1
  {
    \cs_set_eq:cc { spb@text#1script@core } { spb@text#1script@save }
    \cs_set_eq:cc { spb@math@#1@core } { spb@math@#1@save }
  }
\cs_new_protected:Npn \spb_mark_core_set_none:n #1
  {
    \cs_set_eq:cN { spb@text#1script@core } \use:n
    \cs_set_eq:cN { spb@math@#1@core } \use:n
  }

\keys_define:nn { spbmark/option }
  {
    text .choice:,
    text/true .code:n   =
      {
        \cs_set:Npn \textsuperscript { \super[textsp] }
        \cs_set:Npn \textsubscript { \sub[textsb] }
      },
    text/false .code:n  =
      {
        \cs_set:Npn \textsuperscript { \spb@textsuperscript@core }
        \cs_set:Npn \textsubscript { \spb@textsubscript@core }
      },
    text .default:n     = true,
    math .choice:,
    math/true .code:n   =
      {
        \cs_set:Npn \sp { \super[mathsp] }
        \cs_set:Npn \sb { \sub[mathsb] }
      },
    math/false .code:n  =
      {
        \cs_set:Npn \sp { \spb@math@super@core }
        \cs_set:Npn \sb { \spb@math@sub@core }
      },
    math .default:n     = true,
    foot .choice:,
    foot/true .code:n   =
      {
        \cs_set:Npn \@makefnmark
          { \hbox:n { \fnmarkfont{\super[fnmark]{\@thefnmark}} } }
      },
    foot/false .code:n  =
      { \cs_set:Npn \@makefnmark { \spb@@makefnmark@save } },
    foot .default:n     = true,
    both .meta:n        = { text = #1,math = #1 },
    both .default:n     = true,
    all .meta:n         = { text = #1,math = #1,foot = #1 },
    all .default:n      = true,
    spcore .choice:,
    spcore .value_required:n = true,
    spcore/trad .code:n = \spb_mark_core_set_trad:n { super },
    spcore/none .code:n = \spb_mark_core_set_none:n { super },
    spcore .initial:n   = trad,
    sbcore .choice:,
    sbcore .value_required:n = true,
    sbcore/trad .code:n = \spb_mark_core_set_trad:n { sub },
    sbcore/none .code:n = \spb_mark_core_set_none:n { sub },
    sbcore .initial:n   = trad
  }
\char_set_catcode_active:N \~
\keys_define:nn { spbmark/option }
  {
    math* .choice:,
    math*/true .code:n  =
      {
        \AfterPreamble
          {
            \group_begin:
            \char_set_lccode:nn { `\~ } { `\^ }
            \lowercase{\group_end:\cs_set:Npn ~} { \super[mathsp*] }
            \group_begin:
            \char_set_lccode:nn { `\~ } { `\_ }
            \lowercase{\group_end:\cs_set:Npn ~} { \sub[mathsb*] }
            \char_set_mathcode:nn { `\^ } { "8000 }
            \char_set_catcode_other:N \^
            \char_set_catcode_other:N \_
          }
      },
    math*/false .code:n =
      {
        \AfterPreamble
          {
            \char_set_catcode_math_superscript:N \^
            \char_set_catcode_math_subscript:N \_
            \char_set_mathcode:nn { `\^ } { "005E }
          }
      },
    math* .default:n    = true
  }
\char_set_catcode_space:N \~
\tl_if_exist:NTF \ftntm@font
  { \tl_set_eq:NN \fnmarkfont \ftntm@font }
  { \tl_set_eq:NN \fnmarkfont \normalfont }

\cs_if_exist:NTF \ProcessKeyOptions
  { \ProcessKeyOptions[spbmark/option] }
  {
    \RequirePackage{l3keys2e}
    \ProcessKeysOptions{spbmark/option}
  }

\tl_new:N \g__spb_mark_case_init_tl
\cs_new_protected:Npn \spb_local_case_init:nnn #1#2#3
  {
    \str_case:Vn \g__spb_mark_case_init_tl
      {
        { super } {#1}
        { sub } {#2}
        { supersub } {#3}
      }
  }
\NewDocumentCommand{\spb@both@vsep@assign}
  {>{\SplitArgument{1}{,}}m}
  {\spb_supersub_both_vsep:nn #1}
\cs_new_protected:Npn \spb_supersub_both_vsep:nn #1#2
  {
    \tl_if_novalue:nTF {#2}
      {
        \tl_set:Nn \l__spb_super_vsep_ii_tl { #1/2 }
        \tl_set:Nn \l__spb_sub_vsep_ii_tl { #1/2 }
      }
      {
        \tl_set:Nn \l__spb_super_vsep_ii_tl {#1}
        \tl_set:Nn \l__spb_sub_vsep_ii_tl {#2}
      }
  }
\cs_new_protected:Npn \defspbstyle #1#2
  {
    \spb_define:n
      {
        style/#1 .undefine:,
        style/#1 .code:n = \spb_set:n {#2}
      }
  }
\cs_new_protected:Npn \spbshortkv #1#2
  { \spb_define:n { #1 .meta:n = {#2} } }
\clist_map_inline:nn
  { textsp,textsb,mathsp,mathsb,mathsp*,mathsb*,fnmark }
  {
    \defspbstyle{#1}{}
    \spbshortkv{#1}{style = #1}
  }
\spb_define:n
  {
    mode .tl_set:N      = \l__spb_mode_value_tl,
    mode .initial:n     = match,
    style .choice:,
    style .value_required:n = true,
    vsep .code:n        = \spb@both@vsep@assign{#1},
    vsep .initial:n     = 0.6ex,
    halign .tl_set:N    = \l__spb_supersub_halign_tl,
    halign .initial:n   = l,
    spvmove .tl_set:N   = \l__spb_super_vmove_tl,
    spvmove .initial:n  = 0pt,
    sphmove .tl_set:N   = \l__spb_super_hmove_tl,
    sphmove .initial:n  = 0pt,
    sbvmove .tl_set:N   = \l__spb_sub_vmove_tl,
    sbvmove .initial:n  = 0pt,
    sbhmove .tl_set:N   = \l__spb_sub_hmove_tl,
    sbhmove .initial:n  = 0pt,
    spbhmove .tl_set:N  = \l__spb_supersub_hmove_tl,
    spbhmove .initial:n = 0pt,
    vmove .code:n       =
      {
        \spb_local_case_init:nnn
          { \tl_set:Nn \l__spb_super_vmove_tl {#1} }
          { \tl_set:Nn \l__spb_sub_vmove_tl {#1} }
          { \spb@both@vsep@assign{#1} }
      },
    hmove .code:n       =
      {
        \spb_local_case_init:nnn
          { \tl_set:Nn \l__spb_super_hmove_tl {#1} }
          { \tl_set:Nn \l__spb_sub_hmove_tl {#1} }
          { \tl_set:Nn \l__spb_supersub_hmove_tl {#1} }
      },
    nohmove .meta:n     = { sphmove = 0pt,sbhmove = 0pt },
    novmove .meta:n     = { spvmove = 0pt,sbvmove = 0pt }
  }

\cs_new:Npn \spb_box_super_move_up_i:n #1
  { \box_move_up:nn {#1} { \box_use:N \g__super_i_inner_box } }
\cs_new:Npn \spb_box_sub_move_down_i:n #1
  { \box_move_down:nn {#1} { \box_use:N \g__sub_i_inner_box } }
\cs_new:Npn \spb_box_super_move_up_ii:n #1
  { \box_move_up:nn {#1} { \box_use:N \g__super_ii_box } }
\cs_new:Npn \spb_box_sub_move_down_ii:n #1
  { \box_move_down:nn {#1} { \box_use:N \g__sub_ii_box } }
\cs_new:Npn \spb_box_vmove_i:nn #1
  {
    \str_case:nn {#1}
      {
        { super } { \spb_box_super_move_up_i:n }
        { sub } { \spb_box_sub_move_down_i:n }
      }
  }
\cs_generate_variant:Nn \spb_box_super_move_up_ii:n { V }
\cs_generate_variant:Nn \spb_box_sub_move_down_ii:n { V }
\providecommand{\hbox_overlap_center:n}[1]
  {\hbox_to_zero:n { \hss #1\hss }}
\cs_new:Npn \spb_hbox_overlap_vmove_ii:n #1
  {
    \use:c { hbox_overlap_#1:n }
      { \spb_box_super_move_up_ii:V \l__spb_super_vsep_ii_tl }
    \use:c { hbox_overlap_#1:n }
      { \spb_box_sub_move_down_ii:V \l__spb_sub_vsep_ii_tl }
  }

\tl_new:N \l__spb_super_cmd_ii_tl
\tl_new:N \l__spb_sub_cmd_ii_tl

\spb_define:n
  {
    spcmd .tl_set:N = \l__spb_super_cmd_i_tl,
    sbcmd .tl_set:N = \l__spb_sub_cmd_i_tl,
    spbcmd .code:n  = \spb@both@cmd@assign{#1},
    cmd .code:n     =
      {
        \spb_local_case_init:nnn
          { \tl_set:Nn \l__spb_super_cmd_i_tl {#1} }
          { \tl_set:Nn \l__spb_sub_cmd_i_tl {#1} }
          { \spb@both@cmd@assign{#1} }
      },
    spcmd+ .code:n  = \tl_put_right:Nn \l__spb_super_cmd_i_tl {#1},
    sbcmd+ .code:n  = \tl_put_right:Nn \l__spb_sub_cmd_i_tl {#1},
    spbcmd+ .code:n = \spb@both@cmd@assign+{#1},
    cmd+ .code:n    =
      {
        \spb_local_case_init:nnn
          { \tl_put_right:Nn \l__spb_super_cmd_i_tl {#1} }
          { \tl_put_right:Nn \l__spb_sub_cmd_i_tl {#1} }
          { \spb@both@cmd@assign+{#1} }
      }
  }
\NewDocumentCommand{\spb@both@cmd@assign}
  {t+>{\SplitArgument{1}{,}}m}
  {
    \IfBooleanTF{#1}
      {\spb_supersub_both_addto_cmd:nn #2}
      {\spb_supersub_both_cmd:nn #2}
  }
\cs_new_protected:Npn \spb_supersub_both_cmd:nn #1#2
  {
    \tl_set:Nn \l__spb_super_cmd_ii_tl {#1}
    \tl_if_novalue:nTF {#2}
      { \tl_clear:N \l__spb_sub_cmd_ii_tl }
      { \tl_set:Nn \l__spb_sub_cmd_ii_tl {#2} }
  }
\cs_new_protected:Npn \spb_supersub_both_addto_cmd:nn #1#2
  {
    \tl_put_right:Nn \l__spb_super_cmd_ii_tl {#1}
    \tl_if_novalue:nF {#2} { \tl_put_right:Nn \l__spb_sub_cmd_ii_tl {#2} }
  }

\spb_define:n
  {
    spheight .tl_set:N  = \l__super_height_i_tl,
    sbheight .tl_set:N  = \l__sub_height_i_tl,
    spbheight .tl_set:N = \l__super_height_ii_tl,
    height .code:n      =
      {
        \spb_local_case_init:nnn
          { \tl_set:Nn \l__super_height_i_tl {#1} }
          { \tl_set:Nn \l__sub_height_i_tl {#1} }
          { \tl_set:Nn \l__super_height_ii_tl {#1} }
      },
    spdepth .tl_set:N   = \l__super_depth_i_tl,
    sbdepth .tl_set:N   = \l__sub_depth_i_tl,
    spbdepth .tl_set:N  = \l__sub_depth_ii_tl,
    depth .code:n       =
      {
        \spb_local_case_init:nnn
          { \tl_set:Nn \l__super_depth_i_tl {#1} }
          { \tl_set:Nn \l__sub_depth_i_tl {#1} }
          { \tl_set:Nn \l__sub_depth_ii_tl {#1} }
      }
  }
\cs_new_protected:Npn \spb_ht_dp_assign:nnnn #1#2#3#4
  {
    \tl_if_blank:vF { l__#1_height_#3_tl }
      { \box_set_ht:cv { g__#1_#3#4_box } { l__#1_height_#3_tl } }
    \tl_if_blank:vF { l__#1_depth_i_tl }
      { \box_set_dp:cv { g__#2_#3#4_box } { l__#2_depth_#3_tl } }
  }

\box_new:N \g__super_i_outer_box
\box_new:N \g__super_i_inner_box
\box_new:N \g__sub_i_outer_box
\box_new:N \g__sub_i_inner_box
\box_new:N \g__super_ii_box
\box_new:N \g__sub_ii_box
\dim_new:N \llastwd
\dim_new:N \clastwd
\dim_new:N \rlastwd
\tl_set:Nn \superwd { \box_wd:N \g__super_ii_box }
\tl_set:Nn \subwd { \box_wd:N \g__sub_ii_box }
\tl_set:Nn \maxwd { \dim_max:VV \superwd \subwd }
\tl_set:Nn \l__spb_box_super_wd_i_tl { \box_wd:N \g__super_i_inner_box }
\tl_set:Nn \l__spb_box_sub_wd_i_tl { \box_wd:N \g__sub_i_inner_box }
\providecommand{\NewHookWithArguments}[2]{}
\providecommand{\UseHookWithArguments}[4]{}
\NewHookWithArguments{spb/super/before}{2}
\NewHookWithArguments{spb/super/after}{2}
\NewHookWithArguments{spb/sub/before}{2}
\NewHookWithArguments{spb/sub/after}{2}
\NewHookWithArguments{spb/super*/before}{2}
\NewHookWithArguments{spb/super*/after}{2}
\NewHookWithArguments{spb/sub*/before}{2}
\NewHookWithArguments{spb/sub*/after}{2}
\NewHookWithArguments{cmd+/super/after}{2}
\NewHookWithArguments{cmd+/sub/after}{2}
\cs_new:Npn \spb_math_print_store_i:nnnn #1#2#3#4
  {
    \hbox_gset:cn { g__#1_i_inner_box }
      {
        #3{
            \UseHookWithArguments{spb/#1/before}{2}{#1}{#2}
            \use:c {#4} { \tl_use:c { l__spb_#1_cmd_i_tl }{#2} }
            \UseHookWithArguments{spb/#1/after}{2}{#1}{#2}
          }
      }
    \dim_gset:Nv \rlastwd { l__spb_box_#1_wd_i_tl }
  }
\cs_new:Npn \spb_math_print_store_i:nn #1#2
  {
    \spb_math_print_store_i:nnnn
      {#1} {#2} { \ensuremath } { spb@math@#1@core }
  }
\cs_new:Npn \spb_text_print_store_i:nn #1#2
  {
    \spb_math_print_store_i:nnnn
      {#1} {#2} { \use:n } { spb@text#1script@core }
  }
\cs_new:Npn \spb_math_print_store_ii:nnnnn #1#2#3#4#5
  {
    \hbox_gset:Nn \g__super_ii_box
      {
        #3{
            \UseHookWithArguments{spb/super*/before}{2}{super}{#1}
            #4{\l__spb_super_cmd_ii_tl{#1}}
            \UseHookWithArguments{spb/super*/after}{2}{super}{#1}
          }
      }
    \hbox_gset:Nn \g__sub_ii_box
      {
        #3{
            \UseHookWithArguments{spb/sub*/before}{2}{sub}{#2}
            #5{\l__spb_sub_cmd_ii_tl{#2}}
            \UseHookWithArguments{spb/sub*/after}{2}{sub}{#2}
          }
      }
  }
\cs_new:Npn \spb_math_print_store_ii:nn #1#2
  {
    \spb_math_print_store_ii:nnnnn {#1} {#2}
      { \ensuremath } { \spb@math@super@core } { \spb@math@sub@core }
  }
\cs_new:Npn \spb_text_print_store_ii:nn #1#2
  {
    \spb_math_print_store_ii:nnnnn {#1} {#2}
      { \use:n } { \spb@textsuperscript@core } { \spb@textsubscript@core }
  }
\cs_set_eq:NN \spbifmath \use_ii:nn
\cs_new:Npn \spb@ifmathtrue { \cs_set_eq:NN \spbifmath \use_i:nn }
\cs_new:Npn \spb@ifmathfalse { \cs_set_eq:NN \spbifmath \use_ii:nn }
\cs_new_protected:Npn \spb_mode_switch:nnn #1#2#3
  {
    \str_case:Vn \l__spb_mode_value_tl
      {
        { math }
        {
          \spb@ifmathtrue
          \use:c { spb_math_print_store_#3:nn } {#1} {#2}
        }
        { text }
        {
          \spb@ifmathfalse
          \use:c { spb_text_print_store_#3:nn } {#1} {#2}
        }
        { match }
        {
          \mode_if_math:TF
            {
              \spb@ifmathtrue
              \use:c { spb_math_print_store_#3:nn } {#1} {#2}
            }
            {
              \spb@ifmathfalse
              \use:c { spb_text_print_store_#3:nn } {#1} {#2}
            }
        }
      }
    }
\spb_define:n
  {
    thiswd .code:n      =
      {
        \spb_local_case_init:nnn
          { \tl_set:Nn \l__spb_super_thiswd_mode_tl {#1} }
          { \tl_set:Nn \l__spb_sub_thiswd_mode_tl {#1} } { }
      },
    regex .code:n       =
      {
        \spb_local_case_init:nnn
          { \tl_set:Nn \l__spb_super_regex_next_tl {#1} }
          { \tl_set:Nn \l__spb_sub_regex_next_tl {#1} } { }
      },
    spthiswd .tl_set:N  = \l__spb_super_thiswd_mode_tl,
    spthiswd .initial:n = keep,
    sbthiswd .tl_set:N  = \l__spb_sub_thiswd_mode_tl,
    sbthiswd .initial:n = keep,
    spregex .tl_set:N   = \l__spb_super_regex_next_tl,
    spregex .initial:n  = \c{sub}|\c{textsubscript}|\c{sb}|\_,
    sbregex .tl_set:N   = \l__spb_sub_regex_next_tl,
    sbregex .initial:n  = \c{super}|\c{textsuperscript}|\c{sp}|\^
  }
\cs_new:Npn \spb_clear_thiswd:n #1
  {
    \str_case:nn {#1}
      {
        { super }
        {
          \peek_regex:nF
            { \exp_not:o { \l__spb_super_regex_next_tl } }
            {
              \exp_not:n
                {
                  \dim_zero:N \llastwd
                  \dim_zero:N \clastwd
                  \dim_zero:N \rlastwd
                }
            }
        }
        { sub }
        {
          \peek_regex:nF
            { \exp_not:o { \l__spb_sub_regex_next_tl } }
            {
              \exp_not:n
                {
                  \dim_zero:N \llastwd
                  \dim_zero:N \clastwd
                  \dim_zero:N \rlastwd
                }
            }
        }
      }
  }

\cs_new_protected:Npn \spb_both_newcmd_map:n #1
  {
    \exp_args:Nc \NewDocumentCommand {#1}{sO{}O{}mO{}}
      {
        \group_begin:
        \mode_leave_vertical:
        \tl_gset:Nn \g__spb_mark_case_init_tl {#1}
        \spb_set:n { ##2,##3,##5 }
        \spb_mode_switch:nnn {#1} {##4} { i }
        \spb_content_hbox_set:nn {#1} {##1}
        \spb_ht_dp_assign:nnnn {#1} {#1} { i } { _outer }
        \box_use:c { g__#1_i_outer_box }
        \exp_last_unbraced:Nx
        \group_end:
          {
            \UseHookWithArguments{cmd+/#1/after}{2}{#1}{##4}
            \exp_args:Nv \str_if_eq:nnT
              { l__spb_#1_thiswd_mode_tl } { auto }
              { \spb_clear_thiswd:n {#1} }
          }
      }
  }
\cs_new_protected:Npn \spb_content_hbox_set:nn #1#2
  {
    \dim_gset:Nn \clastwd { (\llastwd + \rlastwd)/2 }
    \tl_set:Nn \abs@hmove@i { \dim_abs:v { l__spb_#1_hmove_tl } }
    \hbox_gset:cn { g__#1_i_outer_box }
      {
        \dim_compare:vNnTF { l__spb_#1_hmove_tl } < { 0pt }
          {
            \hbox_overlap_left:n
              {
                \hbox_overlap_right:n
                  { \spb_box_vmove_i:nn {#1} { \tl_use:c { l__spb_#1_vmove_tl } } }
                \skip_horizontal:n { \abs@hmove@i }
              }
            \IfBooleanT{#2}
              {
                \dim_compare:nNnT { \abs@hmove@i } < { \rlastwd }
                  { \skip_horizontal:n { \rlastwd - \abs@hmove@i } }
              }
          }
          {
            \hbox_to_wd:nn
              { \tl_use:c { l__spb_box_#1_wd_i_tl } + \tl_use:c { l__spb_#1_hmove_tl } }
              { \hss\spb_box_vmove_i:nn {#1} { \tl_use:c { l__spb_#1_vmove_tl } } }
          }
      }
    \dim_gset:Nv \llastwd { l__spb_box_#1_wd_i_tl }
  }
\clist_map_inline:nn { super,sub } { \spb_both_newcmd_map:n {#1} }

\cs_new:Npn \spb_supersub_hmove_if_negative:TF #1#2
  { \dim_compare:VNnTF \l__spb_supersub_hmove_tl < { 0pt } {#1} {#2} }
\tl_set:Nn \abs@hmove@ii { \dim_abs:V \l__spb_supersub_hmove_tl }
\cs_new:Npn \spb_supersub_avoid_overlap:n #1
  {
    \IfBooleanT{#1}
      {
        \dim_compare:nNnT { \abs@hmove@ii } < { \maxwd }
          { \skip_horizontal:n { \maxwd - \abs@hmove@ii } }
      }
  }
\NewDocumentCommand{\supersub}{sO{}mmO{}}
  {
    \group_begin:
    \mode_leave_vertical:
    \tl_gset:Nn \g__spb_mark_case_init_tl { supersub }
    \spb_set:n {#2,#5}
    \spb_mode_switch:nnn {#3} {#4} { ii }
    \spb_ht_dp_assign:nnnn { super } { sub } { ii } { }
    \str_case:VnF \l__spb_supersub_halign_tl
      {
        { l } { \use_i:nnn }
        { c } { \use_ii:nnn }
        { r } { \use_iii:nnn }
      }
      {
        \msg_warning:nn { spbmark } { unsupported-align }
        \use_i:nnn
      }
      {
        \spb_supersub_hmove_if_negative:TF
          {
            \hbox_overlap_left:n
              {
                \spb_hbox_overlap_vmove_ii:n { right }
                \skip_horizontal:n { \abs@hmove@ii }
              }
            \spb_supersub_avoid_overlap:n {#1}
          }
          {
            \hbox:n
              {
                \skip_horizontal:n { \l__spb_supersub_hmove_tl }
                \spb_hbox_overlap_vmove_ii:n { right } 
                \skip_horizontal:n { \maxwd }
              }
          }
      }
      {
        \spb_supersub_hmove_if_negative:TF
          {
            \hbox_overlap_left:n
              {
                \spb_hbox_overlap_vmove_ii:n { center }
                \skip_horizontal:n { \abs@hmove@ii - \maxwd/2 }
              }
            \spb_supersub_avoid_overlap:n {#1}
          }
          {
            \hbox:n
              {
                \skip_horizontal:n { \maxwd/2 + \l__spb_supersub_hmove_tl }
                \spb_hbox_overlap_vmove_ii:n { center } 
                \skip_horizontal:n { \maxwd/2 }
              }
          }
      }
      {
        \spb_supersub_hmove_if_negative:TF
          {
            \hbox_overlap_left:n
              {
                \spb_hbox_overlap_vmove_ii:n { left }
                \skip_horizontal:n { \abs@hmove@ii - \maxwd }
              }
            \spb_supersub_avoid_overlap:n {#1}
          }
          {
            \hbox:n
              {
                \skip_horizontal:n { \maxwd + \l__spb_supersub_hmove_tl }
                \spb_hbox_overlap_vmove_ii:n { left } 
              }
          }
      }
    \group_end:
  }
\msg_new:nnn { spbmark } { unsupported-align }
  {
    Alignment~only~supports~l,~c,~and~r. \\
    The~l~parameter~will~be~used~by~default.
  }
\providecommand{\IfPackageLoadedTF}{\@ifpackageloaded}
\providecommand{\IfFormatAtLeastTF}{\@ifl@t@r\fmtversion}
\IfPackageLoadedTF{easybase}
  {\AddToHook{package/easybase/after}}
  {\use:n}
  { \keys_define:nn { } { ctex/tools .inherit:n = spbmark/option } }
\IfFormatAtLeastTF{2021/11/15}
  {
    \AddToHook{package/altsubsup/after}
      {
        \ifaltsbsp@spbmark
          \SetAltSubSupCommands{\relax}
        \fi
      }
  }{}
\cs_set_eq:NN \spb \supersub
\endinput
%
% End of file `spbmark.sty'.