mtpscriptscale] mt2hrbds
  <9-> s*[\mtpscale] mt2hrbdt}{}
\fi
% \bBiggg support
% Example definitions:
%   \mtp@bBigg@\MTEXE@\thr@@, \mtp@bBigg@\MTEXE@{3.5},..., \mtp@bBigg@\MTEXE@{5.5};
%   \mtp@bBigg@\MTEXF@6,      \mtp@bBigg@\MTEXF@7,    ..., \mtp@bBigg@\MTEXF@{11};
%   \mtp@bBigg@\MTEXG@{12},   \mtp@bBigg@\MTEXG@{14}, ..., \mtp@bBigg@\MTEXG@{24}.
\ifcsname lbrace \endcsname
%   Since ltfssdcl.dtx 2019/08/27 v3.0s, the LaTeX2e kernel
% makes math delimiters robust (including \lbrace, \rbrace).
% Between 2019/08/27 v3.0s and 2020/01/20 v3.0t, the `curly'
% definition `\delimiter"4266308'is in the space-appended
% \csname lbrace\space\endcsname.
%   In this case, the mtpro2 package first lets \lcbrace to
% the robust \lbrace. Then, it redefines \lbrace to be non-
% robust (specifically, to be one of `\delimiter"4266308 ',
% `\delimiter"42B93AE'and `\delimiter"42663B6 ').
%   So, to test if \curlybraces is in force, we compare the
% definitions of \csname lbrace\space\endcsname and \lbrace.
\newcommand*\@ifcurlybraces{%
  \expandafter\ifx\csname lbrace \endcsname\lbrace
    \expandafter\@firstoftwo
  \else
    \expandafter\@secondoftwo
  \fi
}
\else
%   Prior to ltfssdcl.dtx 2019/08/27 v3.0s, \lcbrace pointed
% to the non-robust \lbrace (\let\lcbrace=\lbrace by mtpro2).
% So it suffices to use the test \ifx\lcbrace\lbrace.
%   But after ltfssdcl.dtx 2020/01/20 v3.0t, \lcbrace points
% to the `protected' \lbrace (and there is no space-appended
% \csname lbrace\space\endcsname defined). In this case, the
% test \ifx\lcbrace\lbrace will always be false.
%   To resolve this awkward situation, we can define our own
% left curly brace.
\begingroup
  \curlybraces % redefines \lbrace to `\delimiter"4266308 '
  \ifx\lcbrace\lbrace\else % \lcbrace is `protected' \lbrace
    \expandafter\gdef\csname mtp2@lcbrace\endcsname
      {\delimiter"4266308 }% define our own left curly brace
  \fi
\endgroup
\ifcsname mtp2@lcbrace\endcsname
% For ltfssdcl.dtx 2020/01/20 v3.0t, or later.
\newcommand*\@ifcurlybraces{%
  \expandafter\ifx\csname mtp2@lcbrace\endcsname\lbrace
    \expandafter\@firstoftwo
  \else
    \expandafter\@secondoftwo
  \fi
}
\else
% For ltfssdcl.dtx before 2019/08/27 v3.0s.
\newcommand*\@ifcurlybraces{%
  \ifx\lcbrace\lbrace
    \expandafter\@firstoftwo
  \else
    \expandafter\@secondoftwo
  \fi
}
\fi
\fi
\newcommand*\mtp@bBigg@[3]{%
  {\hbox{%
    \specdelim@#3%
    \ifspecdelim@
      \textfont\thr@@=#1%
      \ifnum
        \ifx#3\{1\else\ifx#3\}1\else
        \ifx#3\lbrace 1\else\ifx#3\rbrace 1\else 0\fi\fi\fi\fi
          =1 %
        \@ifcurlybraces{}{\textfont\thr@@=\MTEXA@}%
      \fi
    \fi
    $\left#3\vcenter to#2\big@size{}\right.\n@space$%
  }}%
}
% Fix \undercbrace and \overcbrace
\def\undercbrace#1{\setbox\z@\hbox{$\displaystyle#1$}%
 \dimen@\wd\z@
 \pointcount@\numexpr(\dimen@-\tMTPscalesize/2)/\tMTPscalesize\relax
 \ifnum\pointcount@<4
  \ifdim\wd\z@<1.35\tMTPscalesize
   \def\thebrace@{\hbox{\MTEXE@\char144}}%
  \else\ifdim\wd\z@<1.65\tMTPscalesize
   \def\thebrace@{\hbox{\MTEXE@\char145}}%
  \else\ifdim\wd\z@<1.95\tMTPscalesize
   \def\thebrace@{\hbox{\MTEXE@\char146}}%
  \else\ifdim\wd\z@<2.25\tMTPscalesize
   \def\thebrace@{\hbox{\MTEXE@\char147}}%
  \else\ifdim\wd\z@<2.55\tMTPscalesize
   \def\thebrace@{\hbox{\MTEXE@\char148}}%
  \else\ifdim\wd\z@<2.85\tMTPscalesize
   \def\thebrace@{\hbox{\MTEXE@\char149}}%
  \else\ifdim\wd\z@<3.15\tMTPscalesize
   \def\thebrace@{\hbox{\MTEXE@\char150}}%
  \else\ifdim\wd\z@<3.45\tMTPscalesize
   \def\thebrace@{\hbox{\MTEXE@\char151}}%
  \else
   \def\thebrace@{\hbox{\MTEXE@\char152}}%
  \fi\fi\fi\fi\fi\fi\fi\fi
 \else
  \ifnum\pointcount@<12
    \advance\pointcount@149
    \def\thebrace@{\hbox{\MTEXE@\char\pointcount@}}%
  \else
   \ifnum\pointcount@<24
    \advance\pointcount@132
    \def\thebrace@{\hbox{\MTEXF@\char\pointcount@}}%
   \else
    \advance\pointcount@120
    \ifnum\pointcount@>149 \pointcount@149 \fi
    \def\thebrace@{\hbox{\MTEXG@\char\pointcount@}}%
   \fi
  \fi
 \fi
 \mathop{\vtop{\ialign{\hfil##\hfil\cr$\displaystyle#1$\crcr\noalign
  {\vskip3pt\nointerlineskip}\thebrace@\cr\noalign{\kern3pt}}}}\limits}%
\def\overcbrace#1{\setbox\z@\hbox{$\displaystyle#1$}%
 \dimen@\wd\z@
 \pointcount@\numexpr(\dimen@-\tMTPscalesize/2)/\tMTPscalesize\relax
 \ifnum\pointcount@<4
  \ifdim\wd\z@<1.35\tMTPscalesize
   \def\thebrace@{\hbox{\MTEXE@\char176}}%
  \else\ifdim\wd\z@<1.65\tMTPscalesize
   \def\thebrace@{\hbox{\MTEXE@\char177}}%
  \else\ifdim\wd\z@<1.95\tMTPscalesize
   \def\thebrace@{\hbox{\MTEXE@\char178}}%
  \else\ifdim\wd\z@<2.25\tMTPscalesize
   \def\thebrace@{\hbox{\MTEXE@\char179}}%
  \else\ifdim\wd\z@<2.55\tMTPscalesize
   \def\thebrace@{\hbox{\MTEXE@\char180}}%
  \else\