Metamath Proof Explorer


Theorem simp231

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

Ref Expression
Assertion simp231 ηθτφψχζφ

Proof

Step Hyp Ref Expression
1 simp31 θτφψχφ
2 1 3ad2ant2 ηθτφψχζφ