Description: Syllogism inference. (Contributed by Peter Mazsa, 18-Sep-2022)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | syl21anbrc.1 | |- ( ph -> ps ) |
|
| syl21anbrc.2 | |- ( ph -> ch ) |
||
| syl21anbrc.3 | |- ( ph -> th ) |
||
| syl21anbrc.4 | |- ( ta <-> ( ( ps /\ ch ) /\ th ) ) |
||
| Assertion | syl21anbrc | |- ( ph -> ta ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | syl21anbrc.1 | |- ( ph -> ps ) |
|
| 2 | syl21anbrc.2 | |- ( ph -> ch ) |
|
| 3 | syl21anbrc.3 | |- ( ph -> th ) |
|
| 4 | syl21anbrc.4 | |- ( ta <-> ( ( ps /\ ch ) /\ th ) ) |
|
| 5 | 1 2 3 | jca31 | |- ( ph -> ( ( ps /\ ch ) /\ th ) ) |
| 6 | 5 4 | sylibr | |- ( ph -> ta ) |