This is an inofficial mirror of http://metamath.tirix.org for personal testing of a visualizer extension only.

Metamath Proof Explorer


Theorem trut

Description: A proposition is equivalent to it being implied by T. . Closed form of mptru . Dual of dfnot . It is to tbtru what a1bi is to tbt . (Contributed by BJ, 26-Oct-2019)

Ref Expression
Assertion trut
|- ( ph <-> ( T. -> ph ) )

Proof

Step Hyp Ref Expression
1 tru
 |-  T.
2 1 a1bi
 |-  ( ph <-> ( T. -> ph ) )