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 ∣ ⊤ } |