Description: Existence of the conditional operator (closed form). (Contributed by NM, 21-Mar-2011) (Proof shortened by BJ, 1-Sep-2022)
Ref | Expression | ||
---|---|---|---|
Assertion | ifexg | |- ( ( A e. V /\ B e. W ) -> if ( ph , A , B ) e. _V ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simpl | |- ( ( A e. V /\ B e. W ) -> A e. V ) |
|
2 | simpr | |- ( ( A e. V /\ B e. W ) -> B e. W ) |
|
3 | 1 2 | ifexd | |- ( ( A e. V /\ B e. W ) -> if ( ph , A , B ) e. _V ) |