Description: Condition for an operation to be a set. (Contributed by Thierry Arnoux, 25-Jun-2019)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | opabex2.1 | |- ( ph -> A e. V ) |
|
| opabex2.2 | |- ( ph -> B e. W ) |
||
| opabex2.3 | |- ( ( ph /\ ps ) -> x e. A ) |
||
| opabex2.4 | |- ( ( ph /\ ps ) -> y e. B ) |
||
| Assertion | opabex2 | |- ( ph -> { <. x , y >. | ps } e. _V ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | opabex2.1 | |- ( ph -> A e. V ) |
|
| 2 | opabex2.2 | |- ( ph -> B e. W ) |
|
| 3 | opabex2.3 | |- ( ( ph /\ ps ) -> x e. A ) |
|
| 4 | opabex2.4 | |- ( ( ph /\ ps ) -> y e. B ) |
|
| 5 | 1 2 | xpexd | |- ( ph -> ( A X. B ) e. _V ) |
| 6 | 3 4 | opabssxpd | |- ( ph -> { <. x , y >. | ps } C_ ( A X. B ) ) |
| 7 | 5 6 | ssexd | |- ( ph -> { <. x , y >. | ps } e. _V ) |