Metamath Proof Explorer


Theorem anabsi7

Description: Absorption of antecedent into conjunction. (Contributed by NM, 20-Jul-1996) (Proof shortened by Wolf Lammen, 18-Nov-2013)

Ref Expression
Hypothesis anabsi7.1 ⊢ ψ → φ ∧ ψ → χ
Assertion anabsi7 ⊢ φ ∧ ψ → χ

Proof

Step Hyp Ref Expression
1 anabsi7.1 ⊢ ψ → φ ∧ ψ → χ
2 1 anabsi6 ⊢ ψ ∧ φ → χ
3 2 ancoms ⊢ φ ∧ ψ → χ