Metamath Proof Explorer


Theorem cnveqi

Description: Equality inference for converse relation. (Contributed by NM, 23-Dec-2008)

Ref Expression
Hypothesis cnveqi.1 ⊢ A = B
Assertion cnveqi ⊢ A -1 = B -1

Proof

Step Hyp Ref Expression
1 cnveqi.1 ⊢ A = B
2 cnveq ⊢ A = B → A -1 = B -1
3 1 2 ax-mp ⊢ A -1 = B -1