Metamath Proof Explorer


Theorem tposres2

Description: The transposition restricted to a set. (Contributed by Zhi Wang, 6-Oct-2025)

Ref Expression
Hypothesis tposres2.1
|- ( ph -> -. (/) e. ( dom F i^i R ) )
Assertion tposres2
|- ( ph -> ( tpos F |` R ) = ( tpos F |` `' `' R ) )

Proof

Step Hyp Ref Expression
1 tposres2.1
 |-  ( ph -> -. (/) e. ( dom F i^i R ) )
2 tposresg
 |-  ( tpos F |` R ) = ( ( tpos F |` `' `' R ) u. ( F |` ( R i^i { (/) } ) ) )
3 resinsn
 |-  ( ( F |` ( R i^i { (/) } ) ) = (/) <-> -. (/) e. ( dom F i^i R ) )
4 1 3 sylibr
 |-  ( ph -> ( F |` ( R i^i { (/) } ) ) = (/) )
5 4 uneq2d
 |-  ( ph -> ( ( tpos F |` `' `' R ) u. ( F |` ( R i^i { (/) } ) ) ) = ( ( tpos F |` `' `' R ) u. (/) ) )
6 2 5 eqtrid
 |-  ( ph -> ( tpos F |` R ) = ( ( tpos F |` `' `' R ) u. (/) ) )
7 un0
 |-  ( ( tpos F |` `' `' R ) u. (/) ) = ( tpos F |` `' `' R )
8 6 7 eqtrdi
 |-  ( ph -> ( tpos F |` R ) = ( tpos F |` `' `' R ) )