Description: A syllogism inference. (Contributed by NM, 21-Apr-1994)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | sylan2br.1 | ⊢ ( 𝜒 ↔ 𝜑 ) | |
| sylan2br.2 | ⊢ ( ( 𝜓 ∧ 𝜒 ) → 𝜃 ) | ||
| Assertion | sylan2br | ⊢ ( ( 𝜓 ∧ 𝜑 ) → 𝜃 ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | sylan2br.1 | ⊢ ( 𝜒 ↔ 𝜑 ) | |
| 2 | sylan2br.2 | ⊢ ( ( 𝜓 ∧ 𝜒 ) → 𝜃 ) | |
| 3 | 1 | biimpri | ⊢ ( 𝜑 → 𝜒 ) |
| 4 | 3 2 | sylan2 | ⊢ ( ( 𝜓 ∧ 𝜑 ) → 𝜃 ) |