| 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 4366 | . 2 ⊢ (∅ ⊊ (𝐴 ∩ 𝐵) ↔ (𝐴 ∩ 𝐵) ≠ ∅) | |
| 2 | ndisj 4324 | . 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 400 ∃wex 1808 ∈ wcel 2142 ≠ wne 2957 ∩ cin 3903 ⊊ wpss 3905 ∅c0 4285 |
| 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-tru 1572 df-fal 1582 df-ex 1809 df-sb 2096 df-clab 2741 df-cleq 2754 df-clel 2837 df-ne 2958 df-v 3456 df-dif 3907 df-in 3911 df-ss 3921 df-pss 3924 df-nul 4286 |
| This theorem is used by: (None) |
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