Metamath Proof Explorer


Theorem exp43

Description: An exportation inference. (Contributed by NM, 26-Apr-1994)

Ref Expression
Hypothesis exp43.1 ⊢ φ ∧ ψ ∧ χ ∧ θ → τ
Assertion exp43 ⊢ φ → ψ → χ → θ → τ

Proof

Step Hyp Ref Expression
1 exp43.1 ⊢ φ ∧ ψ ∧ χ ∧ θ → τ
2 1 ex ⊢ φ ∧ ψ → χ ∧ θ → τ
3 2 exp4b ⊢ φ → ψ → χ → θ → τ