Description: The value of a function that maps from B to A . (Contributed by AV, 2-Feb-2023)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | mapfvd.m | |- M = ( A ^m B ) |
|
| mapfvd.f | |- ( ph -> F e. M ) |
||
| mapfvd.x | |- ( ph -> X e. B ) |
||
| Assertion | mapfvd | |- ( ph -> ( F ` X ) e. A ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | mapfvd.m | |- M = ( A ^m B ) |
|
| 2 | mapfvd.f | |- ( ph -> F e. M ) |
|
| 3 | mapfvd.x | |- ( ph -> X e. B ) |
|
| 4 | elmapi | |- ( F e. ( A ^m B ) -> F : B --> A ) |
|
| 5 | ffvelcdm | |- ( ( F : B --> A /\ X e. B ) -> ( F ` X ) e. A ) |
|
| 6 | 5 | expcom | |- ( X e. B -> ( F : B --> A -> ( F ` X ) e. A ) ) |
| 7 | 3 4 6 | syl2imc | |- ( F e. ( A ^m B ) -> ( ph -> ( F ` X ) e. A ) ) |
| 8 | 7 1 | eleq2s | |- ( F e. M -> ( ph -> ( F ` X ) e. A ) ) |
| 9 | 2 8 | mpcom | |- ( ph -> ( F ` X ) e. A ) |