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| Mirrors > Home > NFE Home > Th. List > vex | GIF version | ||
| Description: All setvar variables are sets (see isset 2864). Theorem 6.8 of [Quine] p. 43. (Contributed by NM, 5-Aug-1993.) |
| Ref | Expression |
|---|---|
| vex | ⊢ x ∈ V |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eqid 2353 | . 2 ⊢ x = x | |
| 2 | df-v 2862 | . . 3 ⊢ V = {x ∣ x = x} | |
| 3 | 2 | eqabri 2461 | . 2 ⊢ (x ∈ V ↔ x = x) |
| 4 | 1, 3 | mpbir 200 | 1 ⊢ x ∈ V |
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