Description: Given (((a and b) and c) and d), there exists a proof for b. (Contributed by Jarvin Udandy, 3-Sep-2016)
Ref | Expression | ||
---|---|---|---|
Hypothesis | abcdtb.1 | |- ( ( ( ph /\ ps ) /\ ch ) /\ th ) |
|
Assertion | abcdtb | |- ps |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | abcdtb.1 | |- ( ( ( ph /\ ps ) /\ ch ) /\ th ) |
|
2 | 1 | simpli | |- ( ( ph /\ ps ) /\ ch ) |
3 | 2 | simpli | |- ( ph /\ ps ) |
4 | 3 | simpri | |- ps |