Step |
Hyp |
Ref |
Expression |
1 |
|
fcomptf.1 |
|- F/_ x B |
2 |
|
nfcv |
|- F/_ x A |
3 |
|
nfcv |
|- F/_ x D |
4 |
|
nfcv |
|- F/_ x E |
5 |
2 3 4
|
nff |
|- F/ x A : D --> E |
6 |
|
nfcv |
|- F/_ x C |
7 |
1 6 3
|
nff |
|- F/ x B : C --> D |
8 |
5 7
|
nfan |
|- F/ x ( A : D --> E /\ B : C --> D ) |
9 |
|
ffvelrn |
|- ( ( B : C --> D /\ x e. C ) -> ( B ` x ) e. D ) |
10 |
9
|
adantll |
|- ( ( ( A : D --> E /\ B : C --> D ) /\ x e. C ) -> ( B ` x ) e. D ) |
11 |
10
|
ex |
|- ( ( A : D --> E /\ B : C --> D ) -> ( x e. C -> ( B ` x ) e. D ) ) |
12 |
8 11
|
ralrimi |
|- ( ( A : D --> E /\ B : C --> D ) -> A. x e. C ( B ` x ) e. D ) |
13 |
|
ffn |
|- ( B : C --> D -> B Fn C ) |
14 |
13
|
adantl |
|- ( ( A : D --> E /\ B : C --> D ) -> B Fn C ) |
15 |
1
|
dffn5f |
|- ( B Fn C <-> B = ( x e. C |-> ( B ` x ) ) ) |
16 |
14 15
|
sylib |
|- ( ( A : D --> E /\ B : C --> D ) -> B = ( x e. C |-> ( B ` x ) ) ) |
17 |
|
ffn |
|- ( A : D --> E -> A Fn D ) |
18 |
17
|
adantr |
|- ( ( A : D --> E /\ B : C --> D ) -> A Fn D ) |
19 |
|
dffn5 |
|- ( A Fn D <-> A = ( y e. D |-> ( A ` y ) ) ) |
20 |
18 19
|
sylib |
|- ( ( A : D --> E /\ B : C --> D ) -> A = ( y e. D |-> ( A ` y ) ) ) |
21 |
|
fveq2 |
|- ( y = ( B ` x ) -> ( A ` y ) = ( A ` ( B ` x ) ) ) |
22 |
12 16 20 21
|
fmptcof |
|- ( ( A : D --> E /\ B : C --> D ) -> ( A o. B ) = ( x e. C |-> ( A ` ( B ` x ) ) ) ) |