% LaTeX \documentclass[leqno]{article} \usepackage[utf8]{inputenc} \usepackage{url} \usepackage{graphicx} \usepackage{amsmath} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{bm} \usepackage{gellmu} \usepackage[margin=100bp,nohead]{geometry} \setlength{\parskip}{6bp} \setlength{\parindent}{0bp} \pagestyle{plain} \thispagestyle{empty} \title{A Simple Sum} \newlength{\centerskip} \setlength{\centerskip}{\topsep} \newcommand{\hsf}{\hspace*{\fill}} \newcommand{\tdbc}[1]{\hsf\textbf{#1}\hsf} \newenvironment{menulist}{ \begin{list}{}{ \setlength{\topsep}{0bp} \setlength{\labelwidth}{0.03\linewidth} \setlength{\leftmargin}{0.06\linewidth} \setlength{\itemindent}{0bp} \setlength{\itemsep}{-6bp} \setlength{\parsep}{6bp}} }{\end{list}} \newenvironment{Menulist}{ \begin{list}{}{ \setlength{\topsep}{0bp} \setlength{\labelwidth}{0.03\linewidth} \setlength{\leftmargin}{0.06\linewidth} \setlength{\itemindent}{0bp} \setlength{\itemsep}{3bp} \setlength{\parsep}{6bp}} }{\end{list}} \newenvironment{toclist}{\normalsize \begin{list}{}{ }}{\end{list}} \newenvironment{Toclist}{\large \begin{list}{}{ }}{\end{list}} \newenvironment{citations}{ \begin{list}{}{ \setlength{\topsep}{0bp} \setlength{\labelwidth}{0bp} \setlength{\leftmargin}{0.04\linewidth} \setlength{\labelsep}{0bp} \setlength{\itemindent}{-0.2\leftmargin} \setlength{\itemsep}{3bp} \setlength{\parsep}{0bp}} }{\end{list}} \begin{document} \begin{center}\LARGE\bfseries{} A Simple Sum \end{center} \medskip \par{This is a simple summation formula: \[ \sum_{k=1}^{n} {k } \ = \ \frac{n(n+1)}{2} \ \ \ . \] It may be proved easily using mathematical induction. \ } \par{Mathematical induction is part of deductive, not inductive, logic. \ } \end{document}