Description: A mapping is a function, forward direction only with superfluous antecedent removed. (Contributed by Stefan O'Rear, 10-Oct-2014)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | elmapi | |- ( A e. ( B ^m C ) -> A : C --> B ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | elmapex | |- ( A e. ( B ^m C ) -> ( B e. _V /\ C e. _V ) ) |
|
| 2 | elmapg | |- ( ( B e. _V /\ C e. _V ) -> ( A e. ( B ^m C ) <-> A : C --> B ) ) |
|
| 3 | 1 2 | syl | |- ( A e. ( B ^m C ) -> ( A e. ( B ^m C ) <-> A : C --> B ) ) |
| 4 | 3 | ibi | |- ( A e. ( B ^m C ) -> A : C --> B ) |