Metamath Proof Explorer


Theorem sylan2d

Description: A syllogism deduction. (Contributed by NM, 15-Dec-2004)

Ref Expression
Hypotheses sylan2d.1 ⊢ φ → ψ → χ
sylan2d.2 ⊢ φ → θ ∧ χ → τ
Assertion sylan2d ⊢ φ → θ ∧ ψ → τ

Proof

Step Hyp Ref Expression
1 sylan2d.1 ⊢ φ → ψ → χ
2 sylan2d.2 ⊢ φ → θ ∧ χ → τ
3 2 ancomsd ⊢ φ → χ ∧ θ → τ
4 1 3 syland ⊢ φ → ψ ∧ θ → τ
5 4 ancomsd ⊢ φ → θ ∧ ψ → τ