Theorem isseti

Description: A way to say " A is a set" (inference form). (Contributed by NM, 24-Jun-1993) Remove dependencies on axioms. (Revised by BJ, 13-Jul-2019)

	Ref	Expression
Hypothesis	isseti.1	|- A e. _V
Assertion	isseti	|- E. x x = A

Proof

Step	Hyp	Ref	Expression
1		isseti.1	|- A e. _V
2		elisset	|- ( A e. _V -> E. x x = A )
3	1 2	ax-mp	|- E. x x = A