Metamath Proof Explorer


Theorem cnveqd

Description: Equality deduction for converse relation. (Contributed by NM, 6-Dec-2013)

Ref Expression
Hypothesis cnveqd.1 φ A = B
Assertion cnveqd φ A -1 = B -1

Proof

Step Hyp Ref Expression
1 cnveqd.1 φ A = B
2 cnveq A = B A -1 = B -1
3 1 2 syl φ A -1 = B -1