Theorem simp21 979

Description: Simplification of doubly triple conjunction. (Contributed by NM, 17-Nov-2011.)

Assertion

Ref	Expression
simp21	|- ( ( ph /\ ( ps /\ ch /\ th ) /\ ta ) -> ps )

Proof of Theorem simp21

Step	Hyp	Ref	Expression
1		simp1 946	. 2 |- ( ( ps /\ ch /\ th ) -> ps )
2	1	3ad2ant2 968	1 |- ( ( ph /\ ( ps /\ ch /\ th ) /\ ta ) -> ps )

Syntax hints:   -> wi 4   /\ w3a 927

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 105  ax-ia2 106  ax-ia3 107

This theorem depends on definitions:  df-bi 116  df-3an 929

This theorem is referenced by:  simpl21  1024  simpr21  1033  simp121  1078  simp221  1087  simp321  1096