Metamath Proof Explorer


Theorem e20an

Description: Conjunction form of e20 . (Contributed by Alan Sare, 15-Jun-2011) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypotheses e20an.1 ⊢ φ , ψ → χ
e20an.2 ⊢ θ
e20an.3 ⊢ χ ∧ θ → τ
Assertion e20an ⊢ φ , ψ → τ

Proof

Step Hyp Ref Expression
1 e20an.1 ⊢ φ , ψ → χ
2 e20an.2 ⊢ θ
3 e20an.3 ⊢ χ ∧ θ → τ
4 3 ex ⊢ χ → θ → τ
5 1 2 4 e20 ⊢ φ , ψ → τ