% CLS en formato .TEX para libros Generado por David Pacios Izquierdo
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% Version 1.0.1
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\newenvironment{dedicatoria}{
\thispagestyle{empty}
\vspace*{13\baselineskip}
\large\itshape}{\clearpage}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Genera dedicatorias

\newenvironment{prefacio}{
\thispagestyle{empty}
\setlength{\parindent}{8mm}
\vspace*{6\baselineskip}
}{\clearpage}

\definecolor{codegreen}{rgb}{0,0.6,0}
\definecolor{codegray}{rgb}{0.5,0.5,0.5}
\definecolor{codepurple}{rgb}{0.58,0,0.82}
\definecolor{backcolour}{rgb}{0.95,0.95,0.92}
\definecolor{light-gray}{gray}{0.95}

\newmdenv[linecolor=black,backgroundcolor=light-gray]{myframe}


\newenvironment{exercise}[2][Ejercicio]{\begin{myframe}\begin{trivlist}
\item[\hskip \labelsep {\bfseries #1}\hskip \labelsep {\bfseries #2.}]}{\end{trivlist}\end{myframe}}

\newtcolorbox{tcbdoublebox}[1][]{%
  enhanced jigsaw,
  sharp corners,
  colback=white,
  borderline={1pt}{-2pt}{black},
  fontupper={\setlength{\parindent}{20pt}},
  #1
}