ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  trubitru GIF version

Theorem trubitru 1378
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 170 . 2 (⊤ ↔ ⊤)
21bitru 1328 1 ((⊤ ↔ ⊤) ↔ ⊤)
Colors of variables: wff set class
Syntax hints:  wb 104  wtru 1317
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 1319
This theorem is referenced by: (None)
  Copyright terms: Public domain W3C validator