Theorem elnelneq2d 3057

Description: Two classes are not equal if one but not the other is an element of a given class. (Contributed by Rohan Ridenour, 12-Aug-2023.)

Hypotheses

Ref	Expression
elnelneq2d.1	⊢ (𝜑 → 𝐴 ∈ 𝐶)
elnelneq2d.2	⊢ (𝜑 → ¬ 𝐵 ∈ 𝐶)

Assertion

Ref	Expression
elnelneq2d	⊢ (𝜑 → ¬ 𝐴 = 𝐵)

Proof of Theorem elnelneq2d

Step	Hyp	Ref	Expression
1		elnelneq2d.2	. 2 ⊢ (𝜑 → ¬ 𝐵 ∈ 𝐶)
2		simpr 489	. . 3 ⊢ ((𝜑 ∧ 𝐴 = 𝐵) → 𝐴 = 𝐵)
3		elnelneq2d.1	. . . 4 ⊢ (𝜑 → 𝐴 ∈ 𝐶)
4	3	adantr 485	. . 3 ⊢ ((𝜑 ∧ 𝐴 = 𝐵) → 𝐴 ∈ 𝐶)
5	2, 4	eqeltrrd 2863	. 2 ⊢ ((𝜑 ∧ 𝐴 = 𝐵) → 𝐵 ∈ 𝐶)
6	1, 5	mtand 827	1 ⊢ (𝜑 → ¬ 𝐴 = 𝐵)

This proof depends on syntax axioms:  ¬ wn 3   → wi 4   ∧ wa 400   = wceq 1569   ∈ wcel 2142

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1824  ax-4 1838  ax-5 1939  ax-6 1996  ax-7 2037  ax-8 2144  ax-9 2152  ax-ext 2734

This proof depends on definitions:  df-bi 210  df-an 401  df-ex 1809  df-cleq 2754  df-clel 2837

This theorem is used by:  prlngmolem1  29213  mnurndlem1  45019