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Theorem falxorfal 1353
Description: A identity. (Contributed by David A. Wheeler, 2-Mar-2018.)
Assertion
Ref Expression
falxorfal ((⊥ ⊻ ⊥) ↔ ⊥)

Proof of Theorem falxorfal
StepHypRef Expression
1 df-xor 1307 . 2 ((⊥ ⊻ ⊥) ↔ ((⊥ ∨ ⊥) ∧ ¬ (⊥ ∧ ⊥)))
2 oridm 706 . . 3 ((⊥ ∨ ⊥) ↔ ⊥)
3 notfal 1345 . . . 4 (¬ ⊥ ↔ ⊤)
4 anidm 388 . . . 4 ((⊥ ∧ ⊥) ↔ ⊥)
53, 4xchnxbir 638 . . 3 (¬ (⊥ ∧ ⊥) ↔ ⊤)
62, 5anbi12i 447 . 2 (((⊥ ∨ ⊥) ∧ ¬ (⊥ ∧ ⊥)) ↔ (⊥ ∧ ⊤))
7 falantru 1334 . 2 ((⊥ ∧ ⊤) ↔ ⊥)
81, 6, 73bitri 204 1 ((⊥ ⊻ ⊥) ↔ ⊥)
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wa 102  wb 103  wo 661  wtru 1285  wfal 1289  wxo 1306
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-in1 576  ax-in2 577  ax-io 662
This theorem depends on definitions:  df-bi 115  df-tru 1287  df-fal 1290  df-xor 1307
This theorem is referenced by: (None)
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