Theorem neleq12d 2345

Description: Equality theorem for negated membership. (Contributed by FL, 10-Aug-2016.)

Hypotheses

Ref	Expression
neleq12d.1	⊢ (𝜑 → 𝐴 = 𝐵)
neleq12d.2	⊢ (𝜑 → 𝐶 = 𝐷)

Assertion

Ref	Expression
neleq12d	⊢ (𝜑 → (𝐴 ∉ 𝐶 ↔ 𝐵 ∉ 𝐷))

Proof of Theorem neleq12d

Step	Hyp	Ref	Expression
1		neleq12d.1	. . 3 ⊢ (𝜑 → 𝐴 = 𝐵)
2		neleq1 2343	. . 3 ⊢ (𝐴 = 𝐵 → (𝐴 ∉ 𝐶 ↔ 𝐵 ∉ 𝐶))
3	1, 2	syl 14	. 2 ⊢ (𝜑 → (𝐴 ∉ 𝐶 ↔ 𝐵 ∉ 𝐶))
4		neleq12d.2	. . 3 ⊢ (𝜑 → 𝐶 = 𝐷)
5		neleq2 2344	. . 3 ⊢ (𝐶 = 𝐷 → (𝐵 ∉ 𝐶 ↔ 𝐵 ∉ 𝐷))
6	4, 5	syl 14	. 2 ⊢ (𝜑 → (𝐵 ∉ 𝐶 ↔ 𝐵 ∉ 𝐷))
7	3, 6	bitrd 186	1 ⊢ (𝜑 → (𝐴 ∉ 𝐶 ↔ 𝐵 ∉ 𝐷))

Syntax hints:   → wi 4   ↔ wb 103   = wceq 1284   ∉ wnel 2339

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  ax-5 1376  ax-gen 1378  ax-ie1 1422  ax-ie2 1423  ax-4 1440  ax-17 1459  ax-ial 1467  ax-ext 2063

This theorem depends on definitions:  df-bi 115  df-cleq 2074  df-clel 2077  df-nel 2340

This theorem is referenced by: (None)