Metamath Proof Explorer


Theorem ofcfval3

Description: General value of ( F oFC R C ) with no assumptions on functionality of F . (Contributed by Thierry Arnoux, 31-Jan-2017)

Ref Expression
Assertion ofcfval3
|- ( ( F e. V /\ C e. W ) -> ( F oFC R C ) = ( x e. dom F |-> ( ( F ` x ) R C ) ) )

Proof

Step Hyp Ref Expression
1 elex
 |-  ( F e. V -> F e. _V )
2 1 adantr
 |-  ( ( F e. V /\ C e. W ) -> F e. _V )
3 elex
 |-  ( C e. W -> C e. _V )
4 3 adantl
 |-  ( ( F e. V /\ C e. W ) -> C e. _V )
5 dmexg
 |-  ( F e. V -> dom F e. _V )
6 mptexg
 |-  ( dom F e. _V -> ( x e. dom F |-> ( ( F ` x ) R C ) ) e. _V )
7 5 6 syl
 |-  ( F e. V -> ( x e. dom F |-> ( ( F ` x ) R C ) ) e. _V )
8 7 adantr
 |-  ( ( F e. V /\ C e. W ) -> ( x e. dom F |-> ( ( F ` x ) R C ) ) e. _V )
9 simpl
 |-  ( ( f = F /\ c = C ) -> f = F )
10 9 dmeqd
 |-  ( ( f = F /\ c = C ) -> dom f = dom F )
11 9 fveq1d
 |-  ( ( f = F /\ c = C ) -> ( f ` x ) = ( F ` x ) )
12 simpr
 |-  ( ( f = F /\ c = C ) -> c = C )
13 11 12 oveq12d
 |-  ( ( f = F /\ c = C ) -> ( ( f ` x ) R c ) = ( ( F ` x ) R C ) )
14 10 13 mpteq12dv
 |-  ( ( f = F /\ c = C ) -> ( x e. dom f |-> ( ( f ` x ) R c ) ) = ( x e. dom F |-> ( ( F ` x ) R C ) ) )
15 df-ofc
 |-  oFC R = ( f e. _V , c e. _V |-> ( x e. dom f |-> ( ( f ` x ) R c ) ) )
16 14 15 ovmpoga
 |-  ( ( F e. _V /\ C e. _V /\ ( x e. dom F |-> ( ( F ` x ) R C ) ) e. _V ) -> ( F oFC R C ) = ( x e. dom F |-> ( ( F ` x ) R C ) ) )
17 2 4 8 16 syl3anc
 |-  ( ( F e. V /\ C e. W ) -> ( F oFC R C ) = ( x e. dom F |-> ( ( F ` x ) R C ) ) )