Theorem cnvex

Description: The converse of a set is a set. Corollary 6.8(1) of TakeutiZaring p. 26. (Contributed by NM, 19-Dec-2003)

	Ref	Expression
Hypothesis	cnvex.1	$$⊢A\in \mathrm{V}$$
Assertion	cnvex	$$⊢A^{-1}\in \mathrm{V}$$

Proof

Step	Hyp	Ref	Expression
1		cnvex.1	$$⊢A\in \mathrm{V}$$
2		cnvexg	$$⊢A\in \mathrm{V}\to A^{-1}\in \mathrm{V}$$
3	1 2	ax-mp	$$⊢A^{-1}\in \mathrm{V}$$