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 | biorfi | |- ( ph <-> ( ph \/ F. ) ) |
6 | dfifp4 | |- ( if- ( ph , T. , F. ) <-> ( ( -. ph \/ T. ) /\ ( ph \/ F. ) ) ) |
|
7 | 3 5 6 | 3bitr4i | |- ( ph <-> if- ( ph , T. , F. ) ) |