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| Mirrors > Home > ILE Home > Th. List > eqvisset | GIF version | ||
| Description: A class equal to a variable is a set. Note the absence of disjoint variable condition, contrary to isset 2769 and issetri 2772. (Contributed by BJ, 27-Apr-2019.) | 
| Ref | Expression | 
|---|---|
| eqvisset | ⊢ (𝑥 = 𝐴 → 𝐴 ∈ V) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | vex 2766 | . 2 ⊢ 𝑥 ∈ V | |
| 2 | eleq1 2259 | . 2 ⊢ (𝑥 = 𝐴 → (𝑥 ∈ V ↔ 𝐴 ∈ V)) | |
| 3 | 1, 2 | mpbii 148 | 1 ⊢ (𝑥 = 𝐴 → 𝐴 ∈ V) | 
| Colors of variables: wff set class | 
| Syntax hints: → wi 4 = wceq 1364 ∈ wcel 2167 Vcvv 2763 | 
| 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-5 1461 ax-gen 1463 ax-ie1 1507 ax-ie2 1508 ax-8 1518 ax-4 1524 ax-17 1540 ax-i9 1544 ax-ial 1548 ax-ext 2178 | 
| This theorem depends on definitions: df-bi 117 df-sb 1777 df-clab 2183 df-cleq 2189 df-clel 2192 df-v 2765 | 
| This theorem is referenced by: elxp5 5158 xpsnen 6880 fival 7036 | 
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