collectionCollection2007-01-18 11:42:552007-01-19 06:24:07DefinitionSet% this is the default PlanetMath preamble. as your knowledge
% of TeX increases, you will probably want to edit this, but
% it should be fine as is for beginners.
% almost certainly you want these
\usepackage{amssymb}
\usepackage{amsmath}
\usepackage{amsfonts}
% used for TeXing text within eps files
%\usepackage{psfrag}
% need this for including graphics (\includegraphics)
%\usepackage{graphicx}
% for neatly defining theorems and propositions
%\usepackage{amsthm}
% making logically defined graphics
%\usepackage{xypic}
% there are many more packages, add them here as you need them
% define commands here
\PMlinkescapeword{term}
The term \emph{collection} usually denotes a class of sets (as opposed to a set of \PMlinkescapetext{simple} elements).
The term ``\emph{collection} of sets'' is a synonym for ``class of sets''.