Metamath Proof Explorer


Theorem exp4c

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

Ref Expression
Hypothesis exp4c.1 φ ψ χ θ τ
Assertion exp4c φ ψ χ θ τ

Proof

Step Hyp Ref Expression
1 exp4c.1 φ ψ χ θ τ
2 1 expd φ ψ χ θ τ
3 2 expd φ ψ χ θ τ