Metamath Proof Explorer


Theorem opabid2ss

Description: One direction of opabid2 which holds without a Rel A requirement. (Contributed by Thierry Arnoux, 18-Feb-2022)

Ref Expression
Assertion opabid2ss xy|xyAA

Proof

Step Hyp Ref Expression
1 id xyAxyA
2 1 opabssi xy|xyAA