Theorem nom64 341

Description: Part of Lemma 3.3(15) from "Non-Orthomodular Models..." paper. (Contributed by NM, 7-Feb-1999.)

Assertion

Ref	Expression
nom64	(b ≡4 (a ∪ b)) = (a →2 b)

Proof of Theorem nom64

Step	Hyp	Ref	Expression
1		nomb41 299	. 2 (b ≡4 (a ∪ b)) = ((a ∪ b) ≡1 b)
2		nom51 332	. 2 ((a ∪ b) ≡1 b) = (a →2 b)
3	1, 2	ax-r2 36	1 (b ≡4 (a ∪ b)) = (a →2 b)

Syntax hints:   = wb 1   ∪ wo 6   →₂ wi2 13   ≡₁ wid1 18   ≡₄ wid4 21

This theorem was proved from axioms:  ax-a1 30  ax-a2 31  ax-a3 32  ax-a5 34  ax-r1 35  ax-r2 36  ax-r4 37  ax-r5 38

This theorem depends on definitions:  df-a 40  df-t 41  df-f 42  df-i1 44  df-i2 45  df-id1 50  df-id2 51  df-id4 53  df-le1 130  df-le2 131

This theorem is referenced by: (None)