Description: Alternate definition of the universal class (see df-v ). (Contributed by BJ, 30-Nov-2019)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | dfv2 | ⊢ V = { 𝑥 ∣ ⊤ } |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-v | ⊢ V = { 𝑥 ∣ 𝑥 = 𝑥 } | |
| 2 | equid | ⊢ 𝑥 = 𝑥 | |
| 3 | 2 | bitru | ⊢ ( 𝑥 = 𝑥 ↔ ⊤ ) |
| 4 | 3 | abbii | ⊢ { 𝑥 ∣ 𝑥 = 𝑥 } = { 𝑥 ∣ ⊤ } |
| 5 | 1 4 | eqtri | ⊢ V = { 𝑥 ∣ ⊤ } |