Theorem andnand1 32934

Description: Double and in terms of double nand. (Contributed by Anthony Hart, 2-Sep-2011.)

Assertion

Ref	Expression
andnand1	⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) ↔ ((𝜑 ⊼ 𝜓 ⊼ 𝜒) ⊼ (𝜑 ⊼ 𝜓 ⊼ 𝜒)))

Proof of Theorem andnand1

Step	Hyp	Ref	Expression
1		3anass 1122	. . 3 ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) ↔ (𝜑 ∧ (𝜓 ∧ 𝜒)))
2		pm4.63 388	. . . 4 ⊢ (¬ (𝜓 → ¬ 𝜒) ↔ (𝜓 ∧ 𝜒))
3	2	anbi2i 618	. . 3 ⊢ ((𝜑 ∧ ¬ (𝜓 → ¬ 𝜒)) ↔ (𝜑 ∧ (𝜓 ∧ 𝜒)))
4		annim 394	. . 3 ⊢ ((𝜑 ∧ ¬ (𝜓 → ¬ 𝜒)) ↔ ¬ (𝜑 → (𝜓 → ¬ 𝜒)))
5	1, 3, 4	3bitr2i 291	. 2 ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) ↔ ¬ (𝜑 → (𝜓 → ¬ 𝜒)))
6		df-3nand 32931	. . 3 ⊢ ((𝜑 ⊼ 𝜓 ⊼ 𝜒) ↔ (𝜑 → (𝜓 → ¬ 𝜒)))
7	6	notbii 312	. 2 ⊢ (¬ (𝜑 ⊼ 𝜓 ⊼ 𝜒) ↔ ¬ (𝜑 → (𝜓 → ¬ 𝜒)))
8		nannot 1624	. 2 ⊢ (¬ (𝜑 ⊼ 𝜓 ⊼ 𝜒) ↔ ((𝜑 ⊼ 𝜓 ⊼ 𝜒) ⊼ (𝜑 ⊼ 𝜓 ⊼ 𝜒)))
9	5, 7, 8	3bitr2i 291	1 ⊢ ((𝜑 ∧ 𝜓 ∧ 𝜒) ↔ ((𝜑 ⊼ 𝜓 ⊼ 𝜒) ⊼ (𝜑 ⊼ 𝜓 ⊼ 𝜒)))

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 198   ∧ wa 386   ∧ w3a 1113   ⊼ wnan 1614   ⊼ w3nand 32930

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This theorem depends on definitions:  df-bi 199  df-an 387  df-3an 1115  df-nan 1615  df-3nand 32931

This theorem is referenced by: (None)