Description: The domain of the mapping operation, deduction form. (Contributed by Glauco Siliprandi, 21-Dec-2024)
Ref | Expression | ||
---|---|---|---|
Hypotheses | dmmptdff.x | |- F/ x ph |
|
dmmptdff.1 | |- F/_ x B |
||
dmmptdff.a | |- A = ( x e. B |-> C ) |
||
dmmptdff.c | |- ( ( ph /\ x e. B ) -> C e. V ) |
||
Assertion | dmmptdff | |- ( ph -> dom A = B ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dmmptdff.x | |- F/ x ph |
|
2 | dmmptdff.1 | |- F/_ x B |
|
3 | dmmptdff.a | |- A = ( x e. B |-> C ) |
|
4 | dmmptdff.c | |- ( ( ph /\ x e. B ) -> C e. V ) |
|
5 | 3 | dmmpt | |- dom A = { x e. B | C e. _V } |
6 | 4 | elexd | |- ( ( ph /\ x e. B ) -> C e. _V ) |
7 | 1 6 | ralrimia | |- ( ph -> A. x e. B C e. _V ) |
8 | 2 | rabid2f | |- ( B = { x e. B | C e. _V } <-> A. x e. B C e. _V ) |
9 | 7 8 | sylibr | |- ( ph -> B = { x e. B | C e. _V } ) |
10 | 5 9 | eqtr4id | |- ( ph -> dom A = B ) |