Theorem li3 244

Description: Introduce Kalmbach implication to the left.

Hypothesis

Ref	Expression
li3.1	a = b

Assertion

Ref	Expression
li3	(c ->3 a) = (c ->3 b)

Proof of Theorem li3

Step	Hyp	Ref	Expression
1		li3.1	. . . . 5 a = b
2	1	lan 70	. . . 4 (c_|_ ^ a) = (c_|_ ^ b)
3	1	ax-r4 36	. . . . 5 a_|_ = b_|_
4	3	lan 70	. . . 4 (c_|_ ^ a_|_) = (c_|_ ^ b_|_)
5	2, 4	2or 67	. . 3 ((c_|_ ^ a) v (c_|_ ^ a_|_)) = ((c_|_ ^ b) v (c_|_ ^ b_|_))
6	1	lor 66	. . . 4 (c_|_ v a) = (c_|_ v b)
7	6	lan 70	. . 3 (c ^ (c_|_ v a)) = (c ^ (c_|_ v b))
8	5, 7	2or 67	. 2 (((c_|_ ^ a) v (c_|_ ^ a_|_)) v (c ^ (c_|_ v a))) = (((c_|_ ^ b) v (c_|_ ^ b_|_)) v (c ^ (c_|_ v b)))
9		df-i3 45	. 2 (c ->3 a) = (((c_|_ ^ a) v (c_|_ ^ a_|_)) v (c ^ (c_|_ v a)))
10		df-i3 45	. 2 (c ->3 b) = (((c_|_ ^ b) v (c_|_ ^ b_|_)) v (c ^ (c_|_ v b)))
11	8, 9, 10	3tr1 60	1 (c ->3 a) = (c ->3 b)

Syntax hints:   = wb 1  _|_wn 4   v wo 6   ^ wa 7   ->3 wi3 15

This theorem is referenced by:  2i3 246  ud3lem0a 252  bina1 274  i31 502  i3aa 503  i3btr 510  i3li3 521  i3th2 526  i3th3 527  i3th4 528

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

This theorem depends on definitions:  df-a 39  df-i3 45

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