Theorem 3impa

Description: Importation from double to triple conjunction. (Contributed by NM, 20-Aug-1995) (Revised to shorten 3imp by Wolf Lammen, 20-Jun-2022.)

	Ref	Expression
Hypothesis	3impa.1	|- ( ( ( ph /\ ps ) /\ ch ) -> th )
Assertion	3impa	|- ( ( ph /\ ps /\ ch ) -> th )

Proof

Step	Hyp	Ref	Expression
1		3impa.1	|- ( ( ( ph /\ ps ) /\ ch ) -> th )
2		df-3an	|- ( ( ph /\ ps /\ ch ) <-> ( ( ph /\ ps ) /\ ch ) )
3	2 1	sylbi	|- ( ( ph /\ ps /\ ch ) -> th )