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Theorem trunantru 1354
Description: A identity. (Contributed by Anthony Hart, 22-Oct-2010.) (Proof shortened by Andrew Salmon, 13-May-2011.)
Assertion
Ref Expression
trunantru (( ⊤ ⊤ ) ↔ ⊥ )

Proof of Theorem trunantru
StepHypRef Expression
1 nannot 1293 . 2 (¬ ⊤ ↔ ( ⊤ ⊤ ))
2 nottru 1348 . 2 (¬ ⊤ ↔ ⊥ )
31, 2bitr3i 242 1 (( ⊤ ⊤ ) ↔ ⊥ )
Colors of variables: wff setvar class
Syntax hints:  ¬ wn 3  wb 176   wnan 1287  wtru 1316  wfal 1317
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 177  df-an 360  df-nan 1288  df-fal 1320
This theorem is referenced by: (None)
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