Description: Syllogism inference combined with a biconditional. (Contributed by BJ, 25-Apr-2019)
Ref | Expression | ||
---|---|---|---|
Hypotheses | sylanblrc.1 | |- ( ph -> ps ) |
|
sylanblrc.2 | |- ch |
||
sylanblrc.3 | |- ( th <-> ( ps /\ ch ) ) |
||
Assertion | sylanblrc | |- ( ph -> th ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | sylanblrc.1 | |- ( ph -> ps ) |
|
2 | sylanblrc.2 | |- ch |
|
3 | sylanblrc.3 | |- ( th <-> ( ps /\ ch ) ) |
|
4 | 2 | a1i | |- ( ph -> ch ) |
5 | 1 4 3 | sylanbrc | |- ( ph -> th ) |