Metamath Proof Explorer


Theorem simpr21

Description: Simplification of conjunction. (Contributed by NM, 9-Mar-2012) (Proof shortened by Wolf Lammen, 24-Jun-2022)

Ref Expression
Assertion simpr21 ηθφψχτφ

Proof

Step Hyp Ref Expression
1 simpr1 ηφψχφ
2 1 3ad2antr2 ηθφψχτφ