Theorem nom52 325

Description: Part of Lemma 3.3(15) from "Non-Orthomodular Models..." paper.

Assertion

Ref	Expression
nom52	((a ∪ b) ≡2 b) = (a →2 b)

Proof of Theorem nom52

Step	Hyp	Ref	Expression
1		ancom 68	. . . . . . . . 9 (b⊥ ∩ a⊥ ) = (a⊥ ∩ b⊥ )
2		anor3 82	. . . . . . . . 9 (a⊥ ∩ b⊥ ) = (a ∪ b)⊥
3	1, 2	ax-r2 35	. . . . . . . 8 (b⊥ ∩ a⊥ ) = (a ∪ b)⊥
4	3	ax-r1 34	. . . . . . 7 (a ∪ b)⊥ = (b⊥ ∩ a⊥ )
5	4	ax-r4 36	. . . . . 6 (a ∪ b)⊥ ⊥ = (b⊥ ∩ a⊥ )⊥
6	5	lor 66	. . . . 5 (b⊥ ∪ (a ∪ b)⊥ ⊥ ) = (b⊥ ∪ (b⊥ ∩ a⊥ )⊥ )
7	4	lan 70	. . . . . 6 (b⊥ ∩ (a ∪ b)⊥ ) = (b⊥ ∩ (b⊥ ∩ a⊥ ))
8	7	lor 66	. . . . 5 (b⊥ ⊥ ∪ (b⊥ ∩ (a ∪ b)⊥ )) = (b⊥ ⊥ ∪ (b⊥ ∩ (b⊥ ∩ a⊥ )))
9	6, 8	2an 72	. . . 4 ((b⊥ ∪ (a ∪ b)⊥ ⊥ ) ∩ (b⊥ ⊥ ∪ (b⊥ ∩ (a ∪ b)⊥ ))) = ((b⊥ ∪ (b⊥ ∩ a⊥ )⊥ ) ∩ (b⊥ ⊥ ∪ (b⊥ ∩ (b⊥ ∩ a⊥ ))))
10		df-id1 49	. . . 4 (b⊥ ≡1 (a ∪ b)⊥ ) = ((b⊥ ∪ (a ∪ b)⊥ ⊥ ) ∩ (b⊥ ⊥ ∪ (b⊥ ∩ (a ∪ b)⊥ )))
11		df-id1 49	. . . 4 (b⊥ ≡1 (b⊥ ∩ a⊥ )) = ((b⊥ ∪ (b⊥ ∩ a⊥ )⊥ ) ∩ (b⊥ ⊥ ∪ (b⊥ ∩ (b⊥ ∩ a⊥ ))))
12	9, 10, 11	3tr1 60	. . 3 (b⊥ ≡1 (a ∪ b)⊥ ) = (b⊥ ≡1 (b⊥ ∩ a⊥ ))
13		nom21 306	. . 3 (b⊥ ≡1 (b⊥ ∩ a⊥ )) = (b⊥ →1 a⊥ )
14	12, 13	ax-r2 35	. 2 (b⊥ ≡1 (a ∪ b)⊥ ) = (b⊥ →1 a⊥ )
15		nomcon2 295	. 2 ((a ∪ b) ≡2 b) = (b⊥ ≡1 (a ∪ b)⊥ )
16		i2i1 259	. 2 (a →2 b) = (b⊥ →1 a⊥ )
17	14, 15, 16	3tr1 60	1 ((a ∪ b) ≡2 b) = (a →2 b)

Syntax hints:   = wb 1  ^⊥ wn 4   ∪ wo 6   ∩ wa 7   →₁ wi1 13   →₂ wi2 14   ≡₁ wid1 19   ≡₂ wid2 20

This theorem is referenced by:  nom63 332

This theorem was proved from axioms:  ax-a1 29  ax-a2 30  ax-a3 31  ax-a5 33  ax-r1 34  ax-r2 35  ax-r4 36  ax-r5 37

This theorem depends on definitions:  df-a 39  df-t 40  df-f 41  df-i1 43  df-i2 44  df-id1 49  df-id2 50  df-le1 122  df-le2 123

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