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%%  Ein Beispiel der DANTE-Edition
%%  Mathematiksatz mit LaTeX
%%  3. Auflage
%%  Beispiel 10-01-4 auf Seite 213.
%%  Copyright (C) 2018 Herbert Voss
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%%  of the LaTeX Project Public License, either version 1.3
%%  of this license or (at your option) any later version.
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\documentclass[10pt]{screxa}
\pagestyle{empty}
\setlength\textwidth{352.81416pt}
\usepackage[utf8]{inputenc}
\AtBeginDocument{\setlength\parindent{0pt}}
%StartShownPreambleCommands
\usepackage{amsmath,amssymb,pst-node} \DeclareMathOperator{\Hom}{Hom}
\DeclareMathOperator{\Mod}{Mod} \DeclareMathOperator{\obj}{obj}
%StopShownPreambleCommands
\begin{document}
Seien $\mathcal{C}:=\mathcal{D}:=\Mod_A$, $M\in \obj(\Mod_A)$ fixiert,
\begin{align*}
     F:=\square\otimes_A M : \Mod_A &\rightarrow \Mod_A, \\
     G:=\Hom_A(M,\square)  : \Mod_A &\rightarrow \Mod_A.
\end{align*}
Diese beiden Funktoren sind adjungiert, mittels
$h(X,Y)(\phi)(x)(m)\rightarrow\phi(x\otimes m)$:\\[10pt]
$\begin{psmatrix}[colsep=-0.3cm, rowsep=0pt]
  \quad\phi{\;} & & {\;} h(X,Y)(\phi)\quad\\
  \Hom_A(M \otimes_A X, Y) & & \Hom_A(X, \Hom_A(M, Y)) \\[1.5cm]
      & L_A^2(M, X; Y)
\end{psmatrix}$
\ncline{|->}{1,1}{1,3}
\ncline[doubleline=true]{2,1}{2,3}\nbput{h(X,Y)}
\naput[nrot=:U,labelsep=0pt]{$\sim$}
\ncline[doubleline=true]{2,1}{3,2}\naput[nrot=:U,labelsep=0pt]{$\sim$}
\ncline[doubleline=true]{3,2}{2,3}\naput[nrot=:U,labelsep=0pt]{$\sim$}
\end{document}