Theorem nomcon2 303

Description: Lemma for "Non-Orthomodular Models..." paper. (Contributed by NM, 7-Feb-1999.)

Assertion

Ref	Expression
nomcon2	(a ≡2 b) = (b⊥ ≡1 a⊥ )

Proof of Theorem nomcon2

Step	Hyp	Ref	Expression
1		ax-a2 31	. . . 4 (a ∪ b⊥ ) = (b⊥ ∪ a)
2		ax-a1 30	. . . . 5 a = a⊥ ⊥
3	2	lor 70	. . . 4 (b⊥ ∪ a) = (b⊥ ∪ a⊥ ⊥ )
4	1, 3	ax-r2 36	. . 3 (a ∪ b⊥ ) = (b⊥ ∪ a⊥ ⊥ )
5		ax-a1 30	. . . 4 b = b⊥ ⊥
6		ancom 74	. . . 4 (a⊥ ∩ b⊥ ) = (b⊥ ∩ a⊥ )
7	5, 6	2or 72	. . 3 (b ∪ (a⊥ ∩ b⊥ )) = (b⊥ ⊥ ∪ (b⊥ ∩ a⊥ ))
8	4, 7	2an 79	. 2 ((a ∪ b⊥ ) ∩ (b ∪ (a⊥ ∩ b⊥ ))) = ((b⊥ ∪ a⊥ ⊥ ) ∩ (b⊥ ⊥ ∪ (b⊥ ∩ a⊥ )))
9		df-id2 51	. 2 (a ≡2 b) = ((a ∪ b⊥ ) ∩ (b ∪ (a⊥ ∩ b⊥ )))
10		df-id1 50	. 2 (b⊥ ≡1 a⊥ ) = ((b⊥ ∪ a⊥ ⊥ ) ∩ (b⊥ ⊥ ∪ (b⊥ ∩ a⊥ )))
11	8, 9, 10	3tr1 63	1 (a ≡2 b) = (b⊥ ≡1 a⊥ )

This proof depends on syntax axioms:   = wb 1  ^⊥ wn 4   ∪ wo 6   ∩ wa 7   ≡₁ wid1 18   ≡₂ wid2 19

This proof depends on axioms:  ax-a1 30  ax-a2 31  ax-r1 35  ax-r2 36  ax-r4 37  ax-r5 38

This proof depends on definitions:  df-a 40  df-id1 50  df-id2 51

This theorem is used by:  nomcon3  304  nom52  333