Description: Existence of the conditional operator (deduction form). (Contributed by SN, 26-Jul-2024)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | ifexd.1 | |- ( ph -> A e. V ) |
|
| ifexd.2 | |- ( ph -> B e. W ) |
||
| Assertion | ifexd | |- ( ph -> if ( ps , A , B ) e. _V ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ifexd.1 | |- ( ph -> A e. V ) |
|
| 2 | ifexd.2 | |- ( ph -> B e. W ) |
|
| 3 | 1 | elexd | |- ( ph -> A e. _V ) |
| 4 | 2 | elexd | |- ( ph -> B e. _V ) |
| 5 | 3 4 | ifcld | |- ( ph -> if ( ps , A , B ) e. _V ) |