The IsEntity(expr) command returns true if the expression expr is an XML entity reference data structure; otherwise, it returns false.

$\mathrm{with}\left(\mathrm{XMLTools}\right)\:$

$\mathrm{IsEntity}\left(\mathrm{XMLEntity}\left(''foo''\right)\right)$

$\mathrm{true}$

$\mathrm{IsEntity}\left(\mathrm{XMLEntity}\left(''\#A06BF''\right)\right)$

$\mathrm{true}$

$\mathrm{IsEntity}\left(\mathrm{XMLElement}\left(''a''\,\left[\right]\,''some\; content''\right)\right)$

$\mathrm{false}$