Description: Restate implication as conditional logic operator. (Contributed by RP, 25-Apr-2020)
Ref | Expression | ||
---|---|---|---|
Assertion | ifpim4 | |- ( ( ph -> ps ) <-> if- ( ps , ps , -. ph ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simpr | |- ( ( ph /\ ps ) -> ps ) |
|
2 | olc | |- ( ps -> ( ph \/ ps ) ) |
|
3 | ifpim23g | |- ( ( ( ph -> ps ) <-> if- ( ps , ps , -. ph ) ) <-> ( ( ( ph /\ ps ) -> ps ) /\ ( ps -> ( ph \/ ps ) ) ) ) |
|
4 | 1 2 3 | mpbir2an | |- ( ( ph -> ps ) <-> if- ( ps , ps , -. ph ) ) |