Metamath Proof Explorer


Theorem simp222

Description: Simplification of conjunction. (Contributed by NM, 9-Mar-2012)

Ref Expression
Assertion simp222 ηθφψχτζψ

Proof

Step Hyp Ref Expression
1 simp22 θφψχτψ
2 1 3ad2ant2 ηθφψχτζψ