Metamath Proof Explorer


Theorem fvpr2OLD

Description: Obsolete version of fvpr2 as of 26-Sep-2024. (Contributed by Jeff Madsen, 20-Jun-2010) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypotheses fvpr2.1
|- B e. _V
fvpr2.2
|- D e. _V
Assertion fvpr2OLD
|- ( A =/= B -> ( { <. A , C >. , <. B , D >. } ` B ) = D )

Proof

Step Hyp Ref Expression
1 fvpr2.1
 |-  B e. _V
2 fvpr2.2
 |-  D e. _V
3 prcom
 |-  { <. A , C >. , <. B , D >. } = { <. B , D >. , <. A , C >. }
4 3 fveq1i
 |-  ( { <. A , C >. , <. B , D >. } ` B ) = ( { <. B , D >. , <. A , C >. } ` B )
5 necom
 |-  ( A =/= B <-> B =/= A )
6 1 2 fvpr1
 |-  ( B =/= A -> ( { <. B , D >. , <. A , C >. } ` B ) = D )
7 5 6 sylbi
 |-  ( A =/= B -> ( { <. B , D >. , <. A , C >. } ` B ) = D )
8 4 7 syl5eq
 |-  ( A =/= B -> ( { <. A , C >. , <. B , D >. } ` B ) = D )