axiom of comprehension | axiom of separation

The axiom of Zermelo-Fraenkel set theory which asserts the existence for any set a and a formula A(y) of a set x consisting of all elements of a satisfying A(y), exists x for all y(y element x congruent y element a⋀A(y)), where exists denotes exists, for all means for all, element denotes "is an element of, " congruent means equivalent, and ⋀ denotes logical AND. This axiom is called the subset axiom by Enderton, while Kunen calls it the comprehension axiom. Itô terms it the axiom of separation, but this name appears to not be used widely in the literature and to have the additional drawback that it is potentially confusing with the separation axioms of Hausdorff arising in topology.