Metamath Proof Explorer

Theorem truan

Description: True can be removed from a conjunction. (Contributed by FL, 20-Mar-2011) (Proof shortened by Wolf Lammen, 21-Jul-2019)

Ref Expression
Assertion truan 
|- ( ( T. /\ ph ) <-> ph )

Proof

Step Hyp Ref Expression
1 tru 
 |-  T.
2 1 biantrur 
 |-  ( ph <-> ( T. /\ ph ) )
3 2 bicomi 
 |-  ( ( T. /\ ph ) <-> ph )