Description: Add top ad a conjunct. (Contributed by Giovanni Mascellani, 24-May-2019)
Ref | Expression | ||
---|---|---|---|
Hypothesis | tradd.1 | |- ( ph <-> ps ) |
|
Assertion | tradd | |- ( ph <-> ( T. /\ ps ) ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | tradd.1 | |- ( ph <-> ps ) |
|
2 | truan | |- ( ( T. /\ ps ) <-> ps ) |
|
3 | 1 2 | bitr4i | |- ( ph <-> ( T. /\ ps ) ) |