Theorem falxortru 1360

Description: A ⊻ identity. (Contributed by David A. Wheeler, 9-May-2015.)

Assertion

Ref	Expression
falxortru	⊢ (( ⊥ ⊻ ⊤ ) ↔ ⊤ )

Proof of Theorem falxortru

Step	Hyp	Ref	Expression
1		df-xor 1305	. 2 ⊢ (( ⊥ ⊻ ⊤ ) ↔ ¬ ( ⊥ ↔ ⊤ ))
2		falbitru 1352	. . 3 ⊢ (( ⊥ ↔ ⊤ ) ↔ ⊥ )
3	2	notbii 287	. 2 ⊢ (¬ ( ⊥ ↔ ⊤ ) ↔ ¬ ⊥ )
4		notfal 1349	. 2 ⊢ (¬ ⊥ ↔ ⊤ )
5	1, 3, 4	3bitri 262	1 ⊢ (( ⊥ ⊻ ⊤ ) ↔ ⊤ )

Syntax hints:  ¬ wn 3   ↔ wb 176   ⊻ wxo 1304   ⊤ 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-xor 1305  df-tru 1319  df-fal 1320

This theorem is referenced by: (None)