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Theorem nottru 1349
Description: A  -. identity. (Contributed by Anthony Hart, 22-Oct-2010.)
Assertion
Ref Expression
nottru  |-  ( -. T.  <-> F.  )

Proof of Theorem nottru
StepHypRef Expression
1 df-fal 1295 . 2  |-  ( F.  <->  -. T.  )
21bicomi 130 1  |-  ( -. T.  <-> F.  )
Colors of variables: wff set class
Syntax hints:   -. wn 3    <-> wb 103   T. wtru 1290   F. wfal 1294
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106
This theorem depends on definitions:  df-bi 115  df-fal 1295
This theorem is referenced by:  truxortru  1355
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