schoolthm.sty

\NeedsTeXFormat{LaTeX2e}

\ProvidesPackage{schoolthm}[2020/08/09 v0.1 (G Sokolov)]
\PackageInfo{schoolthm}{Additional theorem-like styles.}

\RequirePackage{amsmath}
\RequirePackage{amsthm}

% Theorems.
\newtheorem{lemma}{Lemma}
\newtheorem*{lemma*}{Lemma}
\newtheorem{theorem}{Theorem}
\newtheorem*{theorem*}{Theorem}
\newtheorem{corollary}{Corollary}
\newtheorem*{corollary*}{Corollary}
\newtheorem{proposition}{Proposition}
\newtheorem*{proposition*}{Proposition}
\newtheorem{assumption}{Assumption}
\newtheorem*{assumption*}{Assumption}
\newtheorem{definition}{Definition}
\newtheorem*{definition*}{Definition}
% More.
\newtheorem*{remark*}{Remark}
\newtheorem*{terminology*}{Terminology}
\newtheorem*{notation*}{Notation}
\newtheorem*{convention*}{Convention}

\newenvironment{example*}
  {\paragraph*{Example.}\begin{itemize}\item[]}
  {\end{itemize}}

\newenvironment{exercise*}
  {\paragraph*{Exercise.}\begin{itemize}\item[]}
  {\end{itemize}}

\newenvironment{algorithm*}
  {\paragraph*{Algorithm.}\begin{itemize}\item[]}
  {\end{itemize}}

% https://tex.stackexchange.com/questions/53978/custom-theorem-numbering
\newtheorem{innercustomgeneric}{\customgenericname}
\providecommand{\customgenericname}{}
\newcommand{\newcustomtheorem}[2]{%
  \newenvironment{#1}[1]
  {%
   \renewcommand\customgenericname{#2}%
   \renewcommand\theinnercustomgeneric{##1}%
   \innercustomgeneric
  }
  {\endinnercustomgeneric}
}