Description: Existence of an operation class abstraction (special case). (Contributed by FL, 17-May-2010) (Revised by Mario Carneiro, 1-Sep-2015)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | mpoexg.1 | |- F = ( x e. A , y e. B |-> C ) | |
| Assertion | mpoexg | |- ( ( A e. R /\ B e. S ) -> F e. _V ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | mpoexg.1 | |- F = ( x e. A , y e. B |-> C ) | |
| 2 | elex | |- ( B e. S -> B e. _V ) | |
| 3 | elex | |- ( B e. _V -> B e. _V ) | |
| 4 | 3 | ralrimivw | |- ( B e. _V -> A. x e. A B e. _V ) | 
| 5 | 2 4 | syl | |- ( B e. S -> A. x e. A B e. _V ) | 
| 6 | 1 | mpoexxg | |- ( ( A e. R /\ A. x e. A B e. _V ) -> F e. _V ) | 
| 7 | 5 6 | sylan2 | |- ( ( A e. R /\ B e. S ) -> F e. _V ) |