Metamath Proof Explorer


Theorem cic1st2ndbr

Description: Rewrite the predicate of isomorphic objects with separated parts. (Contributed by Zhi Wang, 27-Oct-2025)

Ref Expression
Assertion cic1st2ndbr
|- ( P e. ( ~=c ` C ) -> ( 1st ` P ) ( ~=c ` C ) ( 2nd ` P ) )

Proof

Step Hyp Ref Expression
1 cic1st2nd
 |-  ( P e. ( ~=c ` C ) -> P = <. ( 1st ` P ) , ( 2nd ` P ) >. )
2 id
 |-  ( P e. ( ~=c ` C ) -> P e. ( ~=c ` C ) )
3 1 2 eqeltrrd
 |-  ( P e. ( ~=c ` C ) -> <. ( 1st ` P ) , ( 2nd ` P ) >. e. ( ~=c ` C ) )
4 df-br
 |-  ( ( 1st ` P ) ( ~=c ` C ) ( 2nd ` P ) <-> <. ( 1st ` P ) , ( 2nd ` P ) >. e. ( ~=c ` C ) )
5 3 4 sylibr
 |-  ( P e. ( ~=c ` C ) -> ( 1st ` P ) ( ~=c ` C ) ( 2nd ` P ) )