Theorem necon3abid 2244

Description: Deduction from equality to inequality. (Contributed by NM, 21-Mar-2007.)

Hypothesis

Ref	Expression
necon3abid.1	⊢ (𝜑 → (𝐴 = 𝐵 ↔ 𝜓))

Assertion

Ref	Expression
necon3abid	⊢ (𝜑 → (𝐴 ≠ 𝐵 ↔ ¬ 𝜓))

Proof of Theorem necon3abid

Step	Hyp	Ref	Expression
1		df-ne 2206	. 2 ⊢ (𝐴 ≠ 𝐵 ↔ ¬ 𝐴 = 𝐵)
2		necon3abid.1	. . 3 ⊢ (𝜑 → (𝐴 = 𝐵 ↔ 𝜓))
3	2	notbid 592	. 2 ⊢ (𝜑 → (¬ 𝐴 = 𝐵 ↔ ¬ 𝜓))
4	1, 3	syl5bb 181	1 ⊢ (𝜑 → (𝐴 ≠ 𝐵 ↔ ¬ 𝜓))

Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 98   = wceq 1243   ≠ wne 2204

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-in1 544  ax-in2 545

This theorem depends on definitions:  df-bi 110  df-ne 2206

This theorem is referenced by:  necon3bbid  2245  fndmdif  5272  expnegap0  9263