Theorem necon3abii 2281

Description: Deduction from equality to inequality. (Contributed by NM, 9-Nov-2007.)

Hypothesis

Ref	Expression
necon3abii.1	⊢ (𝐴 = 𝐵 ↔ 𝜑)

Assertion

Ref	Expression
necon3abii	⊢ (𝐴 ≠ 𝐵 ↔ ¬ 𝜑)

Proof of Theorem necon3abii

Step	Hyp	Ref	Expression
1		df-ne 2246	. 2 ⊢ (𝐴 ≠ 𝐵 ↔ ¬ 𝐴 = 𝐵)
2		necon3abii.1	. 2 ⊢ (𝐴 = 𝐵 ↔ 𝜑)
3	1, 2	xchbinx 639	1 ⊢ (𝐴 ≠ 𝐵 ↔ ¬ 𝜑)

Syntax hints:  ¬ wn 3   ↔ wb 103   = wceq 1284   ≠ wne 2245

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-in1 576  ax-in2 577

This theorem depends on definitions:  df-bi 115  df-ne 2246

This theorem is referenced by:  necon3bbii  2282  necon3bii  2283  nesym  2290  n0rf  3260  gcd0id  10370