Metamath Proof Explorer


Theorem impl

Description: Export a wff from a left conjunct. (Contributed by Mario Carneiro, 9-Jul-2014)

Ref Expression
Hypothesis impl.1 φ ψ χ θ
Assertion impl φ ψ χ θ

Proof

Step Hyp Ref Expression
1 impl.1 φ ψ χ θ
2 1 expd φ ψ χ θ
3 2 imp31 φ ψ χ θ