Theorem eqneltrrd 2858

Description: If a class is not an element of another class, an equal class is also not an element. Deduction form. (Contributed by David Moews, 1-May-2017.) (Proof shortened by Wolf Lammen, 13-Nov-2019.)

Hypotheses

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

Assertion

Ref	Expression
eqneltrrd	⊢ (𝜑 → ¬ 𝐵 ∈ 𝐶)

Proof of Theorem eqneltrrd

Step	Hyp	Ref	Expression
1		eqneltrrd.1	. . 3 ⊢ (𝜑 → 𝐴 = 𝐵)
2	1	eqcomd 2743	. 2 ⊢ (𝜑 → 𝐵 = 𝐴)
3		eqneltrrd.2	. 2 ⊢ (𝜑 → ¬ 𝐴 ∈ 𝐶)
4	2, 3	eqneltrd 2857	1 ⊢ (𝜑 → ¬ 𝐵 ∈ 𝐶)

Syntax hints:  ¬ wn 3   → wi 4   = wceq 1542   ∈ wcel 2114

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1797  ax-4 1811  ax-5 1912  ax-6 1969  ax-7 2010  ax-8 2116  ax-9 2124  ax-ext 2709

This theorem depends on definitions:  df-bi 207  df-an 396  df-ex 1782  df-cleq 2729  df-clel 2812

This theorem is referenced by:  bitsf1  16377  lssvancl2  20901  lbsind2  21037  lindfind2  21777  2atjlej  39776  2atnelvolN  39884  lmod1zrnlvec  48776