Know this: I do not know what I am doing...
Caveat emptor...
This uses the bm package to manage bold fonts for Times and the varbm package to manage bold fonts for Garamond. varbm.sty is just like bm.sty except that it works with the varbold maths version rather than the bold version. It does not, however, include anything corresponding to the support for heavy maths in bm.sty.
First, an example:
\documentclass{article}
%% text fonts
\renewcommand\rmdefault{txr}
\newcommand\gmfamily{\fontfamily{mdugm}\selectfont}
%% New math versions
\DeclareMathVersion{varnormal}
\DeclareMathVersion{varbold}
\makeatletter
\newif\iftx@math
\newif\ifmd@math
\newcommand\txmath{%
\mathversion{normal}%
\ifmd@math
\global\let\bm\oldbm
\fi
\tx@mathtrue
\md@mathfalse
\global\let\oldvarbm\varbm
\global\let\varbm\bm}
\newcommand\mdmath{%
\mathversion{varnormal}%
\iftx@math
\global\let\varbm\oldvarbm
\fi
\md@mathtrue
\tx@mathfalse
\global\let\oldbm\bm
\global\let\bm\varbm}
\AtBeginDocument{\txmath}
\makeatother
\newcommand\varboldmath{\mathversion{varbold}}
% these commands should not be needed and are here just for comparison
\newcommand\txboldmath{\mathversion{bold}}
\newcommand\mdboldmath{\mathversion{varbold}}
%% Math symbol fonts
%% some examples only
%% Math letters from txfonts and mdugm
\SetSymbolFont{letters}{normal}{OML}{txmi}{m}{it}
\SetSymbolFont{letters}{bold}{OML}{txmi}{bx}{it}
\SetSymbolFont{letters}{varnormal}{OML}{mdugm}{m}{it}
\SetSymbolFont{letters}{varbold}{OML}{mdugm}{b}{it}
%% Math operators
\SetSymbolFont{operators}{normal}{OT1}{txr}{m}{n}
\SetSymbolFont{operators}{bold}{OT1}{txr}{bx}{n}
\SetSymbolFont{operators}{varnormal}{OT1}{mdugm}{m}{n}
\SetSymbolFont{operators}{varbold}{OT1}{mdugm}{b}{n}
%% Math symbols
\SetSymbolFont{symbols}{normal}{OMS}{txsy}{m}{n}
\SetSymbolFont{symbols}{bold}{OMS}{txsy}{bx}{n}
\SetSymbolFont{symbols}{varnormal}{OMS}{mdugm}{m}{n}
\SetSymbolFont{symbols}{varbold}{OMS}{mdugm}{b}{n}
%% Large symbols
\SetSymbolFont{largesymbols}{normal}{OMX}{txex}{m}{n}
\SetSymbolFont{largesymbols}{bold}{OMX}{txex}{bx}{n}
\SetSymbolFont{largesymbols}{varnormal}{OMX}{mdugm}{m}{n}
\SetSymbolFont{largesymbols}{varbold}{OMX}{mdugm}{b}{n}
%% Math alphabets, at most 16 families
%% some examples only
\SetMathAlphabet{\mathrm}{normal}{OT1}{txr}{m}{n}
\SetMathAlphabet{\mathrm}{bold}{OT1}{txr}{bx}{n}
\SetMathAlphabet{\mathrm}{varnormal}{OT1}{mdugm}{m}{n}
\SetMathAlphabet{\mathrm}{varbold}{OT1}{mdugm}{b}{n}
\SetMathAlphabet{\mathit}{normal}{OT1}{txr}{m}{it}
\SetMathAlphabet{\mathit}{bold}{OT1}{txr}{bx}{it}
\SetMathAlphabet{\mathit}{varnormal}{OT1}{mdugm}{m}{it}
\SetMathAlphabet{\mathit}{varbold}{OT1}{mdugm}{b}{it}
\usepackage{bm,varbm}
\begin{document}
This is Times font. $a^2 + b^2 = c^2$. Math font
\[
\sum_i \int_a^b \left( \frac1{K+1} \oplus\alpha_i \right) \,\mathrm{d}x = 0
\]
and bold math font
{\txboldmath\[
\sum_i \int_a^b \left( \frac1{K+1} \oplus\alpha_i \right) \,\mathrm{d}x = 0
\]}
\[
\bm{\sum_i \int_a^b \left( \frac1{K+1} \oplus\alpha_i \right) \,\mathrm{d}x = 0}
\]
\[
\varbm{\sum_i \int_a^b \left( \frac1{K+1} \oplus\alpha_i \right) \,\mathrm{d}x = 0}
\]
\gmfamily\mdmath
This is Garamond font. $a^2 + b^2 = c^2$. Math font
\[
\sum_i \int_a^b \left( \frac1{K+1} \oplus\alpha_i \right) \,\mathrm{d}x = 0
\]
and bold math font
{\mdboldmath\[
\sum_i \int_a^b \left( \frac1{K+1} \oplus\alpha_i \right) \,\mathrm{d}x = 0
\]}
\[
\bm{\sum_i \int_a^b \left( \frac1{K+1} \oplus\alpha_i \right) \,\mathrm{d}x = 0}
\]
\[
\varbm{\sum_i \int_a^b \left( \frac1{K+1} \oplus\alpha_i \right) \,\mathrm{d}x = 0}
\]
\end{document}
When Times maths is enabled either by default or using \txmath, the following happens:
- maths version
normal is used;
\bm uses Times bold maths; \varbm uses Times bold maths.
When Garamond maths is activated using \mdmath, the following happens:
- maths version
varnormal is used;
\bm uses Garamond varbold maths; \varbm uses Garamond varbold maths.
Package code (all the legal stuff is just because I copied the bm.sty file and just did a few find-and-replace, deleted a few lines and tested it - hence, it is a derived work under the licensing terms and has to be designated as such):
%%
%% This is file `varbm.sty',
%%
%% Additions and changes (mostly find and replace)
%% are copyright 2015 Clea F. Rees
%%
%% Code from bm.sty (see below)
%% bm.sty is copyright 1993-2015
%% The LaTeX3 Project and any individual authors listed elsewhere
%% in this file
%% Copyright 1996 1997 1998 1999 2002 2003 2004 David Carlisle Frank Mittelbach
%% Development of the bm package was commissioned by Y&Y Inc.
%% http://www.yandy.com
%
% This work may be distributed and/or modified under the
% conditions of the LaTeX Project Public License, either version 1.3
% of this license or (at your option) any later version.
% The latest version of this license is in
% http://www.latex-project.org/lppl.txt
% and version 1.3c or later is part of all distributions of LaTeX
% version 2005/12/01 or later.
%
% This work has the LPPL maintenance status `maintained'.
%
% The Current Maintainer of this work is Clea F. Rees.
%
% This work consists of the file varbm.sty.
%
% The file varbm.sty is a derived work under the terms of the
% LPPL. It is based on bm.sty dated 2014/10/28 v1.1c which is part of The
% Standard LaTeX `Tools Bundle'. A copy of that work, including the
% unmodified version of bm.sty is available from http://ctan.org/pkg/bm.
%
%%
\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{varbm}
[2015/08/02 v0.00001 Variable Bold Symbol Support]
\def\varbm#1#2{%
\let\varbm@pmb\install@mathalphabet
\let\varbm@pmb@\getanddefine@fonts
\let\varbm@pmb@@\or
\edef\varbm@general{\f@encoding/\f@family/\f@series/\f@shape/\f@size}%
\@tempcnta#2%
\count@-\count18%
\advance\count@-\@tempcnta
\advance\count@15\relax
\ifnum\count@<\z@
\advance\@tempcnta\count@
\fi
\let\or\relax
\expandafter\let\csname varbm@#1table\endcsname\@gobble
\def\varbm@define##1{%
\expandafter\xdef\csname varbm@#1table\endcsname{%
\csname varbm@#1table\endcsname\or##1}}%
\def\getanddefine@fonts##1##2{%
\def\@tempa{##2}%
\def\@tempb####1##1####2####3\@nil{\def\@tempb{####2}}%
\expandafter\expandafter\expandafter
\@tempb\csname mv@#1\endcsname\@nil
\ifx\@tempa\@tempb
\varbm@define\m@ne
\else
\edef\@tempa{sym#1\expandafter\@gobblefour\string##1}%
\ifnum\@tempcnta<%
\expandafter\ifx\csname\@tempa\endcsname\relax
\@ne
\else
\m@ne
\fi
\varbm@define\z@
\else
\expandafter\ifx\csname\@tempa\endcsname\relax
\begingroup
\escapechar\m@ne
\edef\@tempb{\endgroup
\noexpand\split@name
\expandafter\string\@tempb}%
\@tempb/\@nil
\expandafter\ifx
\csname symvarbold\expandafter\@gobblefour\string##1\endcsname
\relax
\expandafter\new@mathgroup\csname\@tempa\endcsname
\expandafter\new@symbolfont\csname\@tempa\endcsname
\f@encoding\f@family\f@series\f@shape
\advance\@tempcnta\m@ne
\else
\def\varbm@expand####1##1####2####3\@nil{\def\varbm@expand{####2}}%
\expandafter\expandafter\expandafter
\varbm@expand\csname mv@varbold\endcsname\@nil
\ifx\varbm@expand\@tempb
\expandafter\let\csname\@tempa\expandafter\endcsname
\csname symvarbold\expandafter
\@gobblefour\string##1\endcsname
\else
\expandafter\new@mathgroup\csname\@tempa\endcsname
\expandafter\new@symbolfont\csname\@tempa\endcsname
\f@encoding\f@family\f@series\f@shape
\advance\@tempcnta\m@ne
\fi
\fi
\else
\PackageInfo{varbm}%
{Symbol font \@tempa\space already defined.\MessageBreak
Not overwriting it}%
\fi
\count@\csname\@tempa\endcsname
\advance\count@-##1%
\varbm@define{\the\count@\relax}%
\fi
\fi}%
\let\install@mathalphabet\@gobbletwo
\mv@normal
\expandafter\xdef\csname varbm@#1table\endcsname{%
\noexpand\ifcase\@tempcnta
\csname varbm@#1table\endcsname
\noexpand\else
\z@
\noexpand\fi}%
\expandafter\split@name\varbm@general\@nil
\let\install@mathalphabet\varbm@pmb
\let\getanddefine@fonts\varbm@pmb@
\let\or\varbm@pmb@@}
\ifx\varbmmax\@undefined
\chardef\varbmmax=4
\fi
\ifx\mv@varbold\@undefined
\def\varbm@varboldtable{\m@ne}
\AtEndOfPackage{%
\def\varbm@gr@up#1#2{%
\varbm@pmb{#2}}}
\else
\varbm{varbold}\varbmmax
\@ifundefined{symvarboldoperators}
{}
{\DeclareSymbolFontAlphabet\mathbf{varboldoperators}}
\fi
\begingroup
\catcode`\'=\active
\@firstofone{\endgroup
\def\varbm@general#1#2#3#4#5{%
\begingroup
\let\varbm\@firstofone
\global\let\varbm@command\@empty
\let\@let@token\@empty
\let\protect\@empty
\let\@typeset@protect\@empty
\def\varbm@mathchoice{\varbm@m@thchoice#1}%
\def\varbm@group{\varbm@gr@up#1}%
\let\varbm@table#2%
\let\left\holdinginserts
\let\right\left
\let\mskip\mkern
\let\hskip\kern
\let\varbm@prime\copy
\def'{\varbm@prime\prime\relax}%
\def\@ifnextchar##1##2##3##4{%
\if##1##4%
\expandafter\@firstoftwo
\else
\expandafter\@secondoftwo
\fi
{##2##4}{##3{##4}}}%
\def\GenericWarning##1##2{%
\unvcopy{\GenericWarning{##1}{##2}}}%
\def\GenericError##1##2##3##4{%
\unvcopy{\GenericError{##1}{##2}{##3}{##4}}}%
\let\DN@\copy
\let\FN@\copy
\let\next@\copy
\global\let\varbm@first\@empty
\ifx\uproot@\undefined\else
\def\root##1\of##2{{\root##1\of{##2}}}%
\fi
\def\mathaccentV##1{\mathaccent"\accentclass@}%
\let\@ifnext\@ifnextchar
\let\measure@lhs\copy
\let \rel@break\copy
\let \bin@break\copy
\let \after@open\copy
\let \after@close\copy
\let\ifmmode\iftrue
\let\install@mathalphabet\def
\let\getanddefine@fonts\@gobbletwo
#3%
\def\select@group##1##2##3##4{{%
\protect##1{##4}}}%
\def\use@mathgroup##1##2##3{{%
\protect\use@mathgroup##1{##2}{##3}}}%
\varbm@expand#5\varbm@end
\endgroup
#4}
}
\DeclareRobustCommand\varbm{%
\varbm@general\varboldmath\varbm@varboldtable\mv@varbold\varbm@command}
\protected@edef\varbm#1{\varbm{#1}}
\def\DeclareBoldMathCommand{\@testopt\varbm@declare{varbold}}
\def\varbm@declare[#1]#2{%
\expandafter\varbm@general
\csname #1math\expandafter\endcsname
\csname varbm@#1table\expandafter\endcsname
\csname mv@#1\endcsname
{\varbm@define#2}}
\def\varbmdefine{\DeclareBoldMathCommand[varbold]}
\outer\def\varbm@end{\@@end}
\def\varbm@expand{\afterassignment\varbm@exp@nd\count@`\a}
\def\varbm@exp@nd{\afterassignment\varbm@test\count@`\a}
\def\varbm@test{%
\let\varbm@previous\@let@token
\futurelet\@let@token\varbm@test@}
\def\varbm@test@{%
\ifx\@let@token\bgroup
\expandafter\varbm@group
\else
\expandafter\varbm@test@token
\fi}
\def\varbm@gr@up#1#2{%
\varbm@add{{\varbm@gr@@p#1{{#2}}}}}
\def\varbm@gr@@p#1#2{%
\ifmmode
\varbm@mchoice#1{#2}{#2}{#2}{#2}%
\else
\bfseries#1#2%
\fi}
\def\varbm@test@token#1{%
\let\varbm@next\@empty
\ifx#1\@@end
\else\ifx#1\mathchoice
\let\varbm@next\varbm@mathchoice
\else\ifx#1\mathchar
\afterassignment\varbm@mathchar\count@
\else\ifx#1\mathaccent
\afterassignment\varbm@mathaccent\count@
\else\ifx#1\delimiter
\afterassignment\varbm@delimiter\count@
\else\ifx#1\radical
\afterassignment\varbm@radical\count@
\else\ifx#1\mkern
\varbm@register#1{\muskip\z@}%
\else\ifx#1\kern
\varbm@register#1\skip@
\else\ifx#1\penalty
\varbm@register#1\count@
\else\ifx#1\unvcopy
\let\varbm@next\varbm@add
\else\ifcat\noexpand#1\relax
\xdef\meaning@{\meaning#1}%
\expandafter\varbm@mchar@test\meaning@""\@nil#1%
\else\ifcat.\ifcat a#1.\else#1\fi
\count@\mathcode`#1\relax
\ifnum\count@=\mathcode`\'%
\begingroup\uccode`\~`#1\uppercase{\endgroup
\def\varbm@next{\varbm@expand~}}%
\else
\ifx\varbm@previous\left
\count@\delcode`#1\relax
\varbm@delimiter
\else
\varbm@mathchar
\fi
\fi
\else
\varbm@add{#1}%
\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi\fi
\varbm@next}
\def\varbm@define#1{%
\begingroup
\ifx\varbm@command\@gtempa
\def\mathchar{\global\mathchardef#1}%
\varbm@command
\else
\toks@\expandafter{\varbm@command}%
\xdef#1{\varbm@first\noexpand\varbm@protect\noexpand#1{\the\toks@}}%
\fi
\endgroup}
\def\varbm@protect#1{%
\ifx\protect\@typeset@protect
\expandafter\@firstofone
\else
\protect#1\expandafter\@gobble
\fi}
\def\varbm@mchoice#1#2#3#4#5{%
\mathchoice{\hbox{#1$\displaystyle\m@th#2$}}%
{\hbox{#1$\textstyle\m@th#3$}}%
{\hbox{#1$\scriptstyle\m@th#4$}}%
{\hbox{#1$\scriptscriptstyle\m@th#5$}}}
\def\varbm@m@thchoice#1#2#3#4#5{%
\varbm@add{\varbm@mchoice#1{#2}{#3}{#4}{#5}}}
\def\varbm@register#1#2{%
\def\@tempa{#1\the#2}%
\afterassignment\varbm@r@gister#2}
\def\varbm@r@gister{%
\varbm@xadd{\@tempa\space}}
\def\varbm@mathchar{%
\@tempcntb\count@
\let\@tempa\varbm@group
\varbm@changefam{}%
\ifnum\count@>\@tempcntb
\ifx\varbm@command\@empty
\xdef\@gtempa{\mathchar\the\count@\space}%
\fi
\varbm@xadd{\mathchar\the\count@\space}%
\else
\begingroup
\divide\count@"1000
\let\varbm@expand\relax
\varbm@xadd\varbm@class
\endgroup
\edef\@tempb{%
\noexpand\@tempa{\mathchar\the\count@\space}}%
\@tempb
\fi}
\def\varbm@pmb#1{%
\varbm@add{\varbm@pmb@{#1}}}
\def\varbm@pmb@#1{{%
\setbox\tw@\hbox{$\m@th\mkern.4mu$}%
\mathchoice
\varbm@pmb@@\displaystyle\@empty{#1}%
\varbm@pmb@@\textstyle\@empty{#1}%
\varbm@pmb@@\scriptstyle\defaultscriptratio{#1}%
\varbm@pmb@@\scriptscriptstyle\defaultscriptscriptratio{#1}}}
\def\varbm@pmb@@#1#2#3{{%
\setbox\z@\hbox{$\m@th#1#3$}%
\dimen@#2\wd\tw@
\rlap{\copy\z@}%
\kern\dimen@
\raise1.5\dimen@\rlap{\copy\z@}%
\kern\dimen@
\box\z@}}%
\def\varbm@class{%
\ifcase\count@
\or
\mathop\or
\mathbin\or
\mathrel\or
\mathopen\or
\mathclose\or
\mathpunct\or
\fi}
\def\varbm@add#1{%
\begingroup
\toks@\expandafter{\varbm@command#1}%
\xdef\varbm@command{\the\toks@}%
\endgroup
\varbm@expand}
\def\varbm@xadd#1{%
\begingroup
\toks@\expandafter{\varbm@command}%
\xdef\varbm@command{\the\toks@#1}%
\endgroup
\varbm@expand}
\def\varbm@mathaccent{%
\varbm@changefam{}%
\begingroup
\def\varbm@group##1{\endgroup\varbm@xadd{\bgroup}##1\egroup}%
\def\varbm@test@token{\endgroup\varbm@test@token}%
\let\relax\@empty
\varbm@xadd{\mathaccent\the\count@\space}}
\def\varbm@delimiter{%
\ifnum\count@>\z@
\varbm@changefam{}%
\varbm@changefam{000}%
\fi
\varbm@xadd{\delimiter\the\count@\space}}%
\def\varbm@radical{%
\varbm@changefam{}%
\varbm@changefam{000}%
\varbm@xadd{\radical\the\count@\space}}%
\edef\varbm@mchar@{\meaning\mathchar}
\def\varbm@mchar@test#1"#2"#3\@nil#4{%
\xdef\meaning@{#1}%
\ifx\meaning@\varbm@mchar@
\count@"#2\relax
\varbm@mathchar
\else
\ifx\varbm@previous\@empty
\ifx\relax#4%
\gdef\varbm@first{#4}%
\fi
\fi
\varbm@add{#4}%
\fi}
\def\varbm@changefam#1{%
\@tempcnta\count@
\divide\@tempcnta"1000#1 %
\multiply\@tempcnta"1000#1 %
\advance\@tempcnta-\count@
\divide\@tempcnta-"100#1 %
\@tempcnta\varbm@table
\ifnum\@tempcnta=\m@ne
\let\@tempa\varbm@pmb
\else
\multiply\@tempcnta"100#1 %
\advance\count@\@tempcnta
\fi}
\def\varbm@prime{^\bgroup
\let\varbm@prime'%
\def\prim@s##1\relax{##1\futurelet\@let@token\pr@m@s}%
\prim@s}
\let\varboldsymbol\varbm
\endinput
%%
%% End of file `varbm.sty'.
heavy, then you could use the built-in support for this. (Unless you also needheavy, of course.)