Metamath Proof Explorer


Theorem caofid2

Description: Transfer a right absorption law to the function operation. (Contributed by Mario Carneiro, 28-Jul-2014)

Ref Expression
Hypotheses caofref.1
|- ( ph -> A e. V )
caofref.2
|- ( ph -> F : A --> S )
caofid0.3
|- ( ph -> B e. W )
caofid1.4
|- ( ph -> C e. X )
caofid2.5
|- ( ( ph /\ x e. S ) -> ( B R x ) = C )
Assertion caofid2
|- ( ph -> ( ( A X. { B } ) oF R F ) = ( A X. { C } ) )

Proof

Step Hyp Ref Expression
1 caofref.1
 |-  ( ph -> A e. V )
2 caofref.2
 |-  ( ph -> F : A --> S )
3 caofid0.3
 |-  ( ph -> B e. W )
4 caofid1.4
 |-  ( ph -> C e. X )
5 caofid2.5
 |-  ( ( ph /\ x e. S ) -> ( B R x ) = C )
6 fnconstg
 |-  ( B e. W -> ( A X. { B } ) Fn A )
7 3 6 syl
 |-  ( ph -> ( A X. { B } ) Fn A )
8 2 ffnd
 |-  ( ph -> F Fn A )
9 fnconstg
 |-  ( C e. X -> ( A X. { C } ) Fn A )
10 4 9 syl
 |-  ( ph -> ( A X. { C } ) Fn A )
11 fvconst2g
 |-  ( ( B e. W /\ w e. A ) -> ( ( A X. { B } ) ` w ) = B )
12 3 11 sylan
 |-  ( ( ph /\ w e. A ) -> ( ( A X. { B } ) ` w ) = B )
13 eqidd
 |-  ( ( ph /\ w e. A ) -> ( F ` w ) = ( F ` w ) )
14 5 ralrimiva
 |-  ( ph -> A. x e. S ( B R x ) = C )
15 2 ffvelrnda
 |-  ( ( ph /\ w e. A ) -> ( F ` w ) e. S )
16 oveq2
 |-  ( x = ( F ` w ) -> ( B R x ) = ( B R ( F ` w ) ) )
17 16 eqeq1d
 |-  ( x = ( F ` w ) -> ( ( B R x ) = C <-> ( B R ( F ` w ) ) = C ) )
18 17 rspccva
 |-  ( ( A. x e. S ( B R x ) = C /\ ( F ` w ) e. S ) -> ( B R ( F ` w ) ) = C )
19 14 15 18 syl2an2r
 |-  ( ( ph /\ w e. A ) -> ( B R ( F ` w ) ) = C )
20 fvconst2g
 |-  ( ( C e. X /\ w e. A ) -> ( ( A X. { C } ) ` w ) = C )
21 4 20 sylan
 |-  ( ( ph /\ w e. A ) -> ( ( A X. { C } ) ` w ) = C )
22 19 21 eqtr4d
 |-  ( ( ph /\ w e. A ) -> ( B R ( F ` w ) ) = ( ( A X. { C } ) ` w ) )
23 1 7 8 10 12 13 22 offveq
 |-  ( ph -> ( ( A X. { B } ) oF R F ) = ( A X. { C } ) )