\documentclass[12pt,reqno,a4paper]{amsart}
%\usepackage[utf8]{inputenc} % not needed with up-to-date TeX systems
\usepackage[english]{babel}
\usepackage{amsmath,amsthm,amsfonts,amssymb}
\usepackage{mathtools}
\usepackage{color}
\usepackage{mathrsfs}
\usepackage[all]{xy}
\usepackage{tikz-cd}
\usepackage[normalem]{ulem} % do you *really* need it?
\usepackage{datetime}
\usepackage{hyperref}
\theoremstyle{definition}
\newtheorem{theorem}{Theorem}[section]
\newtheorem{construction}{Construction}
[section]
\newtheorem{observation}{Observation}
\newtheorem{corollary}{Corollary}[section]
\newtheorem{lemma}{Lemma}[section]
\newtheorem{definition}{Definition}[section]
\newtheorem{remark}{Remark}[section]
\newtheorem{proposition}{Proposition}[subsection]
\renewcommand{\qedsymbol}{$\blacksquare$}
\newtheorem{example}{Example}
\newtheorem*{question}{Question}
\newtheorem*{solution}{Solution}
\newtheorem{exercise}{Exercise}
\newcommand{\mc}{\mathcal}
\newcommand{\mf}{\mathfrak}
\newcommand{\mb}{\mathbb}
\newcommand{\xra}{\xrightarrow}
\newcommand{\ra}{\rightarrow}
\newcommand{\rra}{\rightrightarrows}
\pagestyle{myheadings}
\textheight 9.3in
\textwidth 6.5in
\calclayout
% metadata
%\date{\today}
\title{something}
\author{someone}
\address{somewhere}
\begin{document}
%\today
\begin{abstract}
\end{abstract}
\maketitle
\end{document}
I want to use \chapter in above document class. It is showing error saying "undefined control sequence".
I tried using report document class. On \usepackage[english]{babel} it is saying "TeX capacity exceeded, sorry [parameter stack size=10000]. \usepackage[english]". How can I change above document class so that I can use \chapter, \section and all that? Did I add \usepakage that does not work in some documentclasses?
\chapter
Where does\calclayout
come from? And never set margins by hand. Usegeometry
or similar.\calclayout
is the method to be used with AMS classes when you want to change the default page parameters.