mac-thm.sty

%
%%  THEOREM ENVIRONMENTS
%
%%  v2.0.0
%
\NeedsTeXFormat{LaTeX2e}
\ProvidesPackage{mac-thm}[2020/07/04 amsthm patch + defaults]

\RequirePackage{mac-util}

\makeatletter

\RequirePackage{amsthm} % Provide proof environment, QED stack.
\swapnumbers        % Theorem number precedes heading.

% The following resets \end of theorem and proof environments to LaTeX
% defaults, which suppress indentation on immediately following line.

\makeatletter
\patchcmd{\@endtheorem}{\@endpefalse }{}{}{} 
\patchcmd{\endproof}{\@endpefalse}{}{}{}
\makeatother

% Set theorem number prefix counter


\pgfkeys{counter/prefix/.initial={}}
\ProcessPGFOptions

% Initialise main theorem counter

\newtoggle{theorem@counter@initialized}

\newcommand{\InitializeTheoremCounter}{
  \iftoggle{theorem@counter@initialized}{
    \PackageWarning{mac-thm}{Theorems already initialized. Doing nothing.}
  }{
    \pgfkeys{counter/prefix/.get=\prefix}  % scoped to avoid redundant macros
    \ifdefvoid{\prefix}{
      \newtheorem{main@theorem}{}
    }{
      \newtheorem{main@theorem}{}[\prefix]
    }
    \toggletrue{theorem@counter@initialized}
  }
}

\InitializeTheoremCounter

% The prefix will be accessible as \p@main@theorem

% FUNCTION \DeclareTheorem[style = last_used]{name}{heading}
%
% Provides starred unnumbered version

\newcommand{\DeclareTheorem}[3][]{
  \ifstrempty{#1}{
    \newtheorem{#2}[main@theorem]{#3}
    \newtheorem*{#2*}{#3}
  }{
    \theoremstyle{#1}
    \newtheorem{#2}[main@theorem]{#3}
    \newtheorem*{#2*}{#3}
  }
}

% Some defaults

%
\DeclareTheorem[plain]{theorem}{Theorem}
\DeclareTheorem{thm}{Theorem}
\DeclareTheorem{proposition}{Proposition}
\DeclareTheorem{prop}{Proposition}
\DeclareTheorem{lemma}{Lemma}
\DeclareTheorem{corollary}{Corollary}
\DeclareTheorem{cor}{Corollary}
\DeclareTheorem{conjecture}{Conjecture}
\DeclareTheorem{conj}{Conjecture}
\DeclareTheorem{hypothesis}{Hypothesis}
%
\DeclareTheorem[definition]{para}{}
\DeclareTheorem{definition}{Definition}
\DeclareTheorem{defn}{Definition}
%
\DeclareTheorem[remark]{remark}{Remark}
\DeclareTheorem{rmk}{Remark}
\DeclareTheorem{example}{Example}
\DeclareTheorem{eg}{Example}