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Related theorems GIF version |
| Description: All set variables are sets (see isset 1351). Theorem 6.8 of [Quine] p. 43. |
| Ref | Expression |
|---|---|
| visset | ⊢ x ∈ V |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | cleqid 1102 | . 2 ⊢ x = x | |
| 2 | df-v 1349 | . . 3 ⊢ V = {x∣x = x} | |
| 3 | 2 | cleqabi 1176 | . 2 ⊢ (x ∈ V ↔ x = x) |
| 4 | 1, 3 | mpbir 165 | 1 ⊢ x ∈ V |