Description: If an operation value is element of a class for all operands of two classes, then the operation value is an element of the class for specific operands of the two classes. (Contributed by Mario Carneiro, 6-Dec-2014)
Ref | Expression | ||
---|---|---|---|
Assertion | ovrspc2v | |- ( ( ( X e. A /\ Y e. B ) /\ A. x e. A A. y e. B ( x F y ) e. C ) -> ( X F Y ) e. C ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | oveq1 | |- ( x = X -> ( x F y ) = ( X F y ) ) |
|
2 | 1 | eleq1d | |- ( x = X -> ( ( x F y ) e. C <-> ( X F y ) e. C ) ) |
3 | oveq2 | |- ( y = Y -> ( X F y ) = ( X F Y ) ) |
|
4 | 3 | eleq1d | |- ( y = Y -> ( ( X F y ) e. C <-> ( X F Y ) e. C ) ) |
5 | 2 4 | rspc2va | |- ( ( ( X e. A /\ Y e. B ) /\ A. x e. A A. y e. B ( x F y ) e. C ) -> ( X F Y ) e. C ) |