Description: Restate wff as conditional logic operator. (Contributed by RP, 20-Apr-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | ifpid2 | |- ( ph <-> if- ( ph , T. , F. ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | tru | |- T. |
|
| 2 | 1 | olci | |- ( -. ph \/ T. ) |
| 3 | 2 | biantrur | |- ( ( ph \/ F. ) <-> ( ( -. ph \/ T. ) /\ ( ph \/ F. ) ) ) |
| 4 | fal | |- -. F. |
|
| 5 | 4 | biorfri | |- ( ph <-> ( ph \/ F. ) ) |
| 6 | dfifp4 | |- ( if- ( ph , T. , F. ) <-> ( ( -. ph \/ T. ) /\ ( ph \/ F. ) ) ) |
|
| 7 | 3 5 6 | 3bitr4i | |- ( ph <-> if- ( ph , T. , F. ) ) |