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% Copyright © 2022 Maximilian Keßler
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% SOFTWARE.
% 
% This package has been generated by PyTeX, available at
%    https://github.com/kesslermaximilian/PyTeX
% and built from source file 'proof.pysty'.
% It is STRONGLY DISCOURAGED to edit this source file directly, since local
% changes will not be versioned by Git and overwritten by the next build. Always
% edit the source file and build the package again.
% 
% Build details:
%   PyTeX version: v1.0.0-18 (commit 126d420)
%   Source code version: v2.4.0-beta-8 (commit c592a7f)
% 
% This LaTeX package is free software and distributed under the MIT License. You
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\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{mkessler-proof}[2022/01/08 - Automatic references to theorems in proofs. Claim counters within proofs]



\RequirePackage{xkeyval}
\RequirePackage{refcount}

\newif\ifmkessler@proof@english\mkessler@proof@englishtrue
\DeclareOptionX{german}{\mkessler@proof@englishfalse}
\DeclareOptionX{ngerman}{\mkessler@proof@englishfalse}
\DeclareOptionX{english}{\mkessler@proof@englishtrue}

\DeclareOptionX*{\PackageWarning{mkessler-proof}{Unknown '\CurrentOption'}}
\ProcessOptionsX*\relax


\RequirePackage{amssymb}
\RequirePackage{amsthm}
\RequirePackage{etoolbox}
\RequirePackage{xparse}

%%Give claim an own counter and let it reset at each proof
%See also at:
%https://tex.stackexchange.com/questions/283502/reset-counter-at-beginning-of-proof
\newtheorem{claim}{\ifmkessler@proof@english Claim\else Behauptung\fi}
\newtheorem*{claim*}{\ifmkessler@proof@english Claim\else Behauptung\fi}
\AtBeginDocument{\def\claimautorefname{\ifmkessler@proof@english Claim\else Behauptung\fi}}

\newif\ifmkessler@proof@hyperref\mkessler@proof@hyperreffalse
\AtBeginDocument{
    \@ifpackageloaded{hyperref}{
        \mkessler@proof@hyperreftrue
        \let\mkessler@proof@autoref\autoref
    }{
        \mkessler@proof@hyperreftrue
        \let\mkessler@proof@autoref\ref
    }
}

\let\mkessler@proof@saved@proof\proof
\let\mkessler@proof@saved@endproof\endproof

\NewDocumentEnvironment{refproof}{s m o}
{
    % Restore correct counter for claim
    \ifcsdef{themkessler@proof@#2@save@claim}{
        \setcounter{claim}{\value{mkessler@proof@#2@save@claim}}
        \def\mkessler@proof@proofprefix{\ifmkessler@proof@english Continuation of proof\IfBooleanT{#1}{*}\space of\else Fortsetzung des Beweises\IfBooleanT{#1}{*}\space zu\fi}
    }{
        \newcounter{mkessler@proof@#2@save@claim}
        \setcounter{claim}{0}
        \def\mkessler@proof@proofprefix{\ifmkessler@proof@english Proof\ifBooleanT{#1}{*}\space of\else Beweis\IfBooleanT{#1}{*}\space von\fi}
    }
    % Set up counter number printing as subindexed by numbering of the reference
    \let\mkessler@proof@theoldclaim\theclaim
    \def\theclaim{\getrefnumber{#2}.\mkessler@proof@theoldclaim}
    % Now, start the actual proof
    \mkessler@proof@saved@proof[\mkessler@proof@proofprefix\space\mkessler@proof@autoref{#2}\IfValueT{#3}{\space(#3)}]
}
{
    \mkessler@proof@saved@endproof % End proof
    % Save current claim counter for later restoration
    \setcounter{mkessler@proof@#2@save@claim}{\value{claim}}
}

% Proof (with asterisk)
\AtBeginDocument{
    \RenewDocumentEnvironment{proof}{s o}
    {
        \IfNoValueTF{#2}{
            \mkessler@proof@saved@proof[
                \ifmkessler@proof@english
                    Proof\IfBooleanT{#1}{\emph{*}}
                \else
                    Beweis\IfBooleanT{#1}{\emph{*}}
                \fi
            ]
        }{
            \mkessler@proof@saved@proof[\ifmkessler@proof@english Proof\else Beweis\fi\IfBooleanT{#1}{\emph{*}}\space(#2)]
        }
    }
    {
        \mkessler@proof@saved@endproof
    }
}

%%subproof environment - essentially copied proof environment from amsthm and modified its name + symbol
\DeclareRobustCommand{\blackqed}{%
  \ifmmode \mathqed
  \else
    \leavevmode\unskip\penalty9999 \hbox{}\nobreak\hfill
    \quad\hbox{$\blacksquare$}%
  \fi
}

\newenvironment{subproof}[1][\ifmkessler@proof@english Subproof\else Unterbeweis\fi]{\par
  \pushQED{\blackqed}%
  \normalfont \topsep6\p@\@plus6\p@\relax
  \trivlist
  \item[\hskip\labelsep
        \itshape
    #1\@addpunct{.}]\ignorespaces
}{%
  \popQED\endtrivlist\@endpefalse
}


%%%% This might be dropped, but for now is collected here

%%Solution (for exercises)
\newenvironment{solution}[1][]{\begin{proof}[\ifmkessler@proof@english{}Solution\else{}Lösung\fi{}#1]}{\end{proof}}