Theorem neeq12d 2225

Description: Deduction for inequality. (Contributed by NM, 24-Jul-2012.)

Hypotheses

Ref	Expression
neeq1d.1	⊢ (𝜑 → 𝐴 = 𝐵)
neeq12d.2	⊢ (𝜑 → 𝐶 = 𝐷)

Assertion

Ref	Expression
neeq12d	⊢ (𝜑 → (𝐴 ≠ 𝐶 ↔ 𝐵 ≠ 𝐷))

Proof of Theorem neeq12d

Step	Hyp	Ref	Expression
1		neeq1d.1	. . 3 ⊢ (𝜑 → 𝐴 = 𝐵)
2	1	neeq1d 2223	. 2 ⊢ (𝜑 → (𝐴 ≠ 𝐶 ↔ 𝐵 ≠ 𝐶))
3		neeq12d.2	. . 3 ⊢ (𝜑 → 𝐶 = 𝐷)
4	3	neeq2d 2224	. 2 ⊢ (𝜑 → (𝐵 ≠ 𝐶 ↔ 𝐵 ≠ 𝐷))
5	2, 4	bitrd 177	1 ⊢ (𝜑 → (𝐴 ≠ 𝐶 ↔ 𝐵 ≠ 𝐷))

Syntax hints:   → 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  ax-5 1336  ax-gen 1338  ax-4 1400  ax-17 1419  ax-ext 2022

This theorem depends on definitions:  df-bi 110  df-cleq 2033  df-ne 2206

This theorem is referenced by:  3netr3d  2237  3netr4d  2238