Theorem ssneldd 2948

Description: If an element is not in a class, it is also not in a subclass of that class. Deduction form. (Contributed by David Moews, 1-May-2017.)

Hypotheses

Ref	Expression
ssneld.1	⊢ (𝜑 → 𝐴 ⊆ 𝐵)
ssneldd.2	⊢ (𝜑 → ¬ 𝐶 ∈ 𝐵)

Assertion

Ref	Expression
ssneldd	⊢ (𝜑 → ¬ 𝐶 ∈ 𝐴)

Proof of Theorem ssneldd

Step	Hyp	Ref	Expression
1		ssneldd.2	. 2 ⊢ (𝜑 → ¬ 𝐶 ∈ 𝐵)
2		ssneld.1	. . 3 ⊢ (𝜑 → 𝐴 ⊆ 𝐵)
3	2	ssneld 2947	. 2 ⊢ (𝜑 → (¬ 𝐶 ∈ 𝐵 → ¬ 𝐶 ∈ 𝐴))
4	1, 3	mpd 13	1 ⊢ (𝜑 → ¬ 𝐶 ∈ 𝐴)

Syntax hints:  ¬ wn 3   → wi 4   ∈ wcel 1393   ⊆ wss 2917

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-7 1337  ax-gen 1338  ax-ie1 1382  ax-ie2 1383  ax-8 1395  ax-11 1397  ax-4 1400  ax-17 1419  ax-i9 1423  ax-ial 1427  ax-i5r 1428  ax-ext 2022

This theorem depends on definitions:  df-bi 110  df-nf 1350  df-sb 1646  df-clab 2027  df-cleq 2033  df-clel 2036  df-in 2924  df-ss 2931

This theorem is referenced by:  addnqprlemfl  6657  addnqprlemfu  6658  mulnqprlemfl  6673  mulnqprlemfu  6674  cauappcvgprlemladdru  6754