%% 
%%  Ein Beispiel der DANTE-Edition
%%  Mathematiksatz mit LaTeX
%%  3. Auflage
%%  Beispiel 11-02-3 auf Seite 241.
%%  Copyright (C) 2018 Herbert Voss
%% 
%%  It 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.
%%  See http://www.latex-project.org/lppl.txt for details.
%% 
%% ==== 
% Show page(s) 1
%% 
%% 
\documentclass[10pt]{screxa}
\pagestyle{empty}
\setlength\textwidth{352.81416pt}
\setlength\parindent{0pt}
%StartShownPreambleCommands
\newcounter{mathctr}
\newcommand\showMathAlphabets{%
  \setcounter{mathctr}{0}
  \loop\ifnum\themathctr<16
    (\themathctr:~\fontname\textfont\arabic{mathctr})
    \stepcounter{mathctr}
  \repeat}
\DeclareMathVersion{foo} \SetMathAlphabet{\mathbf}{foo}{OMS}{cmsy}{m}{n}
\DeclareMathAlphabet{\mathxy}{OT1}{cmr}{bx}{n}
\SetMathAlphabet{\mathxy}{foo}{OT1}{}{}{}
%StopShownPreambleCommands
\begin{document}
\showMathAlphabets \[ y=f(x) \] \showMathAlphabets
\[ \mathfrak{A}: \mathsf{y}=\int\mathbf{f(x)\mathrm{d}\mathxy{x}} (\mathbf{\Gamma}) \]
\mathversion{foo}
\[ \mathscr{A}: \mathxy{a\cdot\prod}_{i=1}^{10} \mathrm{a}_i\Phi\mathit{a}\times b\]
\showMathAlphabets
\end{document}