Theorem u1lemnoa 660

Description: Lemma for Sasaki implication study.

Assertion

Ref	Expression
u1lemnoa	((a ->1 b)' v a) = a

Proof of Theorem u1lemnoa

Step	Hyp	Ref	Expression
1		anor1 88	. . . 4 ((a ->1 b) ^ a') = ((a ->1 b)' v a)'
2	1	ax-r1 35	. . 3 ((a ->1 b)' v a)' = ((a ->1 b) ^ a')
3		u1lemana 605	. . 3 ((a ->1 b) ^ a') = a'
4	2, 3	ax-r2 36	. 2 ((a ->1 b)' v a)' = a'
5	4	con1 66	1 ((a ->1 b)' v a) = a

Syntax hints:   = wb 1  'wn 4   v wo 6   ^ wa 7   ->1 wi1 12

This theorem is referenced by:  u1lem1 734

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

This theorem depends on definitions:  df-a 40  df-i1 44

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