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Theorem tbtru 1269
Description: A proposition is equivalent to itself being equivalent to T.. (Contributed by Anthony Hart, 14-Aug-2011.)
Assertion
Ref Expression
tbtru  |-  ( ph  <->  (
ph 
<-> T.  ) )

Proof of Theorem tbtru
StepHypRef Expression
1 tru 1263 . 2  |- T.
21tbt 240 1  |-  ( ph  <->  (
ph 
<-> T.  ) )
Colors of variables: wff set class
Syntax hints:    <-> wb 102   T. wtru 1260
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 103  ax-ia2 104  ax-ia3 105
This theorem depends on definitions:  df-bi 114  df-tru 1262
This theorem is referenced by: (None)
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