MPE Home Metamath Proof Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  MPE Home  >  Th. List  >  trubitru Structured version   Visualization version   GIF version

Theorem trubitru 1668
Description: A identity. (Contributed by Anthony Hart, 22-Oct-2010.) (Proof shortened by Andrew Salmon, 13-May-2011.)
Assertion
Ref Expression
trubitru ((⊤ ↔ ⊤) ↔ ⊤)

Proof of Theorem trubitru
StepHypRef Expression
1 biid 251 . 2 (⊤ ↔ ⊤)
21bitru 1644 1 ((⊤ ↔ ⊤) ↔ ⊤)
Colors of variables: wff setvar class
Syntax hints:  wb 196  wtru 1632
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8
This theorem depends on definitions:  df-bi 197  df-tru 1634
This theorem is referenced by:  truxortru  1676
  Copyright terms: Public domain W3C validator