Range 2001-11-19 18:59:41 2002-12-12 21:07:18 Definition \usepackage{amssymb} \usepackage{amsmath} \usepackage{amsfonts} \usepackage{graphicx} \usepackage{xypic} Let $R$ be a binary relation. Then the set of all $y$ such that $x R y$ for some $x$ is called the \emph{range} of $R$. That is, the range of $R$ is the set of all second coordinates in the ordered pairs of $R$. In \PMlinkescapetext{terms} of functions, this means that the range of a function is the full set of values it can take on (the outputs), given the full set of parameters (the inputs). Note that the range is a subset of the codomain.