Theorem eqeq2i

Description: Inference from equality to equivalence of equalities. (Contributed by NM, 26-May-1993)

	Ref	Expression
Hypothesis	eqeq2i.1	|- A = B
Assertion	eqeq2i	|- ( C = A <-> C = B )

Proof

Step	Hyp	Ref	Expression
1		eqeq2i.1	|- A = B
2		eqeq2	|- ( A = B -> ( C = A <-> C = B ) )
3	1 2	ax-mp	|- ( C = A <-> C = B )