\documentclass[a4paper]{scrartcl} \usepackage[utf8]{inputenc} \usepackage{lmodern} \usepackage{amsmath, amsthm, amssymb, amsfonts} \usepackage[mathscr]{euscript} \usepackage{mathtools} \usepackage{physics} \usepackage{cleveref} \newcommand{\ptrans}{\delta} \DeclarePairedDelimiter{\parens}{\lparen}{\rparen} \DeclarePairedDelimiter{\parensc}{\{}{\}} \DeclareMathOperator{\affinehull}{\text{aff}} \DeclareMathOperator{\R}{\mathbb{R}} \DeclareMathOperator{\spanspace}{\text{span}} \DeclareMathOperator{\Hom}{\text{hom}} \theoremstyle{plain} \newtheorem{theorem}{Theorem} \newtheorem{lemma}{Lemma} \theoremstyle{definition} \newtheorem{definition}{Definition} \theoremstyle{remark} \newtheorem{remark}{Remark} \begin{document} \title{A Brief Introduction to Quantum Computation} \author{Tom Krüger} \maketitle \input{content} \end{document}