notval2 - Higher-Order Logic Explorer

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Theorem notval2 149

Description: Another way two write ¬ A, the negation of A.

**Hypothesis**
Ref	Expression
notval2.1	⊢ A:∗

**Assertion**
Ref	Expression
notval2	⊢ ⊤⊧[(¬ A) = [A = ⊥]]

**Proof of Theorem notval2**
Step	Hyp	Ref	Expression
1		wnot 128	. . 3 ⊢ ¬ :(∗ → ∗)
2		notval2.1	. . 3 ⊢ A:∗
3	1, 2	wc 45	. 2 ⊢ (¬ A):∗
4	2	notval 135	. 2 ⊢ ⊤⊧[(¬ A) = [A ⇒ ⊥]]
5		wfal 125	. . . . 5 ⊢ ⊥:∗
6		wim 127	. . . . . . 7 ⊢ ⇒ :(∗ → (∗ → ∗))
7	6, 2, 5	wov 64	. . . . . 6 ⊢ [A ⇒ ⊥]:∗
8	7, 2	simpr 23	. . . . 5 ⊢ ([A ⇒ ⊥], A)⊧A
9	7, 2	simpl 22	. . . . 5 ⊢ ([A ⇒ ⊥], A)⊧[A ⇒ ⊥]
10	5, 8, 9	mpd 146	. . . 4 ⊢ ([A ⇒ ⊥], A)⊧⊥
11	2	pm2.21 143	. . . . 5 ⊢ ⊥⊧A
12	11, 7	adantl 51	. . . 4 ⊢ ([A ⇒ ⊥], ⊥)⊧A
13	10, 12	ded 74	. . 3 ⊢ [A ⇒ ⊥]⊧[A = ⊥]
14	13	ax-cb2 30	. . . . . 6 ⊢ [A = ⊥]:∗
15	14, 2	simpr 23	. . . . 5 ⊢ ([A = ⊥], A)⊧A
16	14, 2	simpl 22	. . . . 5 ⊢ ([A = ⊥], A)⊧[A = ⊥]
17	15, 16	mpbi 72	. . . 4 ⊢ ([A = ⊥], A)⊧⊥
18	17	ex 148	. . 3 ⊢ [A = ⊥]⊧[A ⇒ ⊥]
19	13, 18	dedi 75	. 2 ⊢ ⊤⊧[[A ⇒ ⊥] = [A = ⊥]]
20	3, 4, 19	eqtri 85	1 ⊢ ⊤⊧[(¬ A) = [A = ⊥]]

Colors of variables: type var term

Syntax hints: ∗hb 3 kc 5 = ke 7 ⊤kt 8 [kbr 9 kct 10 ⊧wffMMJ2 11 wffMMJ2t 12 ⊥tfal 108 ¬ tne 110 ⇒ tim 111

This theorem was proved from axioms: ax-syl 15 ax-jca 17 ax-simpl 20 ax-simpr 21 ax-id 24 ax-trud 26 ax-cb1 29 ax-cb2 30 ax-refl 39 ax-eqmp 42 ax-ded 43 ax-ceq 46 ax-beta 60 ax-distrc 61 ax-leq 62 ax-distrl 63 ax-hbl1 93 ax-17 95 ax-inst 103

This theorem depends on definitions: df-ov 65 df-al 116 df-fal 117 df-an 118 df-im 119 df-not 120

This theorem is referenced by: (None)