Theorem exp31

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

	Ref	Expression
Hypothesis	exp31.1	|- ( ( ( ph /\ ps ) /\ ch ) -> th )
Assertion	exp31	|- ( ph -> ( ps -> ( ch -> th ) ) )

Proof

Step	Hyp	Ref	Expression
1		exp31.1	|- ( ( ( ph /\ ps ) /\ ch ) -> th )
2	1	ex	|- ( ( ph /\ ps ) -> ( ch -> th ) )
3	2	ex	|- ( ph -> ( ps -> ( ch -> th ) ) )