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Theorem falxortru 1370
Description: A  \/_ identity. (Contributed by David A. Wheeler, 9-May-2015.)
Assertion
Ref Expression
falxortru  |-  ( (  F.  \/_  T.  )  <->  T.  )

Proof of Theorem falxortru
StepHypRef Expression
1 df-xor 1315 . 2  |-  ( (  F.  \/_  T.  )  <->  -.  (  F.  <->  T.  )
)
2 falbitru 1362 . . 3  |-  ( (  F.  <->  T.  )  <->  F.  )
32notbii 289 . 2  |-  ( -.  (  F.  <->  T.  )  <->  -. 
F.  )
4 notfal 1359 . 2  |-  ( -. 
F. 
<->  T.  )
51, 3, 43bitri 264 1  |-  ( (  F.  \/_  T.  )  <->  T.  )
Colors of variables: wff set class
Syntax hints:   -. wn 3    <-> wb 178    \/_ wxo 1314    T. wtru 1326    F. wfal 1327
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 179  df-xor 1315  df-tru 1329  df-fal 1330
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