Theorem i3abs2 505

Description: Antecedent absorption.

Hypothesis

Ref	Expression
i3abs2.1	(a ->3 (a ->3 (a ->3 b))) = 1

Assertion

Ref	Expression
i3abs2	(a ->3 (a ->3 b)) = 1

Proof of Theorem i3abs2

Step	Hyp	Ref	Expression
1		i3abs2.1	. 2 (a ->3 (a ->3 (a ->3 b))) = 1
2		i3abs1 504	. . 3 (a ->3 (a ->3 (a ->3 b))) = (a ->3 (a ->3 b))
3	2	bi1 110	. 2 ((a ->3 (a ->3 (a ->3 b))) == (a ->3 (a ->3 b))) = 1
4	1, 3	wwbmp 197	1 (a ->3 (a ->3 b)) = 1

Syntax hints:   = wb 1  1wt 9   ->3 wi3 15

This theorem was proved from axioms:  ax-a1 29  ax-a2 30  ax-a3 31  ax-a4 32  ax-a5 33  ax-r1 34  ax-r2 35  ax-r4 36  ax-r5 37  ax-r3 421

This theorem depends on definitions:  df-b 38  df-a 39  df-t 40  df-f 41  df-i3 45  df-le1 122  df-le2 123  df-c1 124  df-c2 125

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