Metamath Proof Explorer


Theorem trcleq12lem

Description: Equality implies bijection. (Contributed by RP, 9-May-2020)

Ref Expression
Assertion trcleq12lem
|- ( ( R = S /\ A = B ) -> ( ( R C_ A /\ ( A o. A ) C_ A ) <-> ( S C_ B /\ ( B o. B ) C_ B ) ) )

Proof

Step Hyp Ref Expression
1 cleq1lem
 |-  ( R = S -> ( ( R C_ A /\ ( A o. A ) C_ A ) <-> ( S C_ A /\ ( A o. A ) C_ A ) ) )
2 trcleq2lem
 |-  ( A = B -> ( ( S C_ A /\ ( A o. A ) C_ A ) <-> ( S C_ B /\ ( B o. B ) C_ B ) ) )
3 1 2 sylan9bb
 |-  ( ( R = S /\ A = B ) -> ( ( R C_ A /\ ( A o. A ) C_ A ) <-> ( S C_ B /\ ( B o. B ) C_ B ) ) )