The call type(expr, equation) checks to see if expr is of type equation, that is, if it is an equality. It returns true if expr is of type equation, and false otherwise.  The calling sequence type(expr, `=`) is a synonym for type(expr, equation).

type/relation

$\mathrm{type}\left(x^2=4\,\mathrm{equation}\right)$

$\mathrm{true}$

$\mathrm{type}\left(5<x^2\&comma;\mathrm{equation}\right)$

$\mathrm{false}$