Theorem truan 1348

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

Assertion

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

Proof of Theorem truan

Step	Hyp	Ref	Expression
1		tru 1335	. . 3 |- T.
2	1	biantrur 301	. 2 |- ( ph <-> ( T. /\ ph ) )
3	2	bicomi 131	1 |- ( ( T. /\ ph ) <-> ph )

Syntax hints:   /\ wa 103   <-> wb 104   T. wtru 1332

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

This theorem depends on definitions:  df-bi 116  df-tru 1334

This theorem is referenced by:  truanfal  1380  truxortru  1397  truxorfal  1398