| Intuitionistic Logic Explorer |
< Previous
Next >
Nearby theorems |
||
| Mirrors > Home > ILE Home > Th. List > ssneldd | GIF version | ||
| 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.) |
| Ref | Expression |
|---|---|
| ssneld.1 | ⊢ (𝜑 → 𝐴 ⊆ 𝐵) |
| ssneldd.2 | ⊢ (𝜑 → ¬ 𝐶 ∈ 𝐵) |
| Ref | Expression |
|---|---|
| ssneldd | ⊢ (𝜑 → ¬ 𝐶 ∈ 𝐴) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ssneldd.2 | . 2 ⊢ (𝜑 → ¬ 𝐶 ∈ 𝐵) | |
| 2 | ssneld.1 | . . 3 ⊢ (𝜑 → 𝐴 ⊆ 𝐵) | |
| 3 | 2 | ssneld 3197 | . 2 ⊢ (𝜑 → (¬ 𝐶 ∈ 𝐵 → ¬ 𝐶 ∈ 𝐴)) |
| 4 | 1, 3 | mpd 13 | 1 ⊢ (𝜑 → ¬ 𝐶 ∈ 𝐴) |
| Colors of variables: wff set class |
| Syntax hints: ¬ wn 3 → wi 4 ∈ wcel 2177 ⊆ wss 3168 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-in1 615 ax-in2 616 ax-5 1471 ax-7 1472 ax-gen 1473 ax-ie1 1517 ax-ie2 1518 ax-8 1528 ax-11 1530 ax-4 1534 ax-17 1550 ax-i9 1554 ax-ial 1558 ax-i5r 1559 ax-ext 2188 |
| This theorem depends on definitions: df-bi 117 df-nf 1485 df-sb 1787 df-clab 2193 df-cleq 2199 df-clel 2202 df-in 3174 df-ss 3181 |
| This theorem is referenced by: 0nelrel 4726 addnqprlemfl 7685 addnqprlemfu 7686 mulnqprlemfl 7701 mulnqprlemfu 7702 cauappcvgprlemladdru 7782 fprodntrivap 11945 fprodssdc 11951 |
| Copyright terms: Public domain | W3C validator |