| Mathbox for Richard Penner |
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| Mirrors > Home > MPE Home > Th. List > Mathboxes > 0pssin | Structured version Visualization version GIF version | ||
| Description: Express that an intersection is not empty. (Contributed by RP, 16-Apr-2020.) |
| Ref | Expression |
|---|---|
| 0pssin | ⊢ (∅ ⊊ (𝐴 ∩ 𝐵) ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝑥 ∈ 𝐵)) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 0pss 4359 | . 2 ⊢ (∅ ⊊ (𝐴 ∩ 𝐵) ↔ (𝐴 ∩ 𝐵) ≠ ∅) | |
| 2 | ndisj 4317 | . 2 ⊢ ((𝐴 ∩ 𝐵) ≠ ∅ ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝑥 ∈ 𝐵)) | |
| 3 | 1, 2 | bitri 278 | 1 ⊢ (∅ ⊊ (𝐴 ∩ 𝐵) ↔ ∃𝑥(𝑥 ∈ 𝐴 ∧ 𝑥 ∈ 𝐵)) |
| Colors of variables: wff setvar class |
| This proof depends on syntax axioms: ↔ wb 209 ∧ wa 401 ∃wex 1811 ∈ wcel 2144 ≠ wne 2955 ⊊ wpss 4013 ∩ cin 4089 ∅c0 4278 |
| This proof depends on axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1827 ax-4 1841 ax-5 1942 ax-6 1999 ax-7 2040 ax-8 2146 ax-9 2154 ax-ext 2732 |
| This proof depends on definitions: df-bi 210 df-an 402 df-tru 1572 df-fal 1582 df-ex 1812 df-sb 2099 df-clab 2739 df-cleq 2752 df-clel 2835 df-ne 2956 df-v 3452 df-ss 3896 df-pss 4014 df-dif 4047 df-in 4091 df-nul 4279 |
| This theorem is used by: (None) |
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