Theorem i3th6 530

Description: Theorem for Kalmbach implication.

Assertion

Ref	Expression
i3th6	((a →3 (a →3 (a →3 b))) →3 (a →3 (a →3 b))) = 1

Proof of Theorem i3th6

Step	Hyp	Ref	Expression
1		i3abs1 504	. . 3 (a →3 (a →3 (a →3 b))) = (a →3 (a →3 b))
2	1	bi1 110	. 2 ((a →3 (a →3 (a →3 b))) ≡ (a →3 (a →3 b))) = 1
3		bii3 498	. 2 (((a →3 (a →3 (a →3 b))) ≡ (a →3 (a →3 b))) →3 ((a →3 (a →3 (a →3 b))) →3 (a →3 (a →3 b)))) = 1
4	2, 3	skmp3 237	1 ((a →3 (a →3 (a →3 b))) →3 (a →3 (a →3 b))) = 1

Syntax hints:   = wb 1   ≡ tb 5  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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