Metamath Proof Explorer


Theorem elisset

Description: An element of a class exists. (Contributed by NM, 1-May-1995) Reduce dependencies on axioms. (Revised by BJ, 29-Apr-2019)

Ref Expression
Assertion elisset A V x x = A

Proof

Step Hyp Ref Expression
1 exsimpl y y = A y V y y = A
2 dfclel A V y y = A y V
3 eqeq1 x = y x = A y = A
4 3 cbvexvw x x = A y y = A
5 1 2 4 3imtr4i A V x x = A