Description: The domain of a set is a set. (Contributed by Glauco Siliprandi, 26-Jun-2021)
| Ref | Expression | ||
|---|---|---|---|
| Hypothesis | dmexd.1 | ⊢ ( 𝜑 → 𝐴 ∈ 𝑉 ) | |
| Assertion | dmexd | ⊢ ( 𝜑 → dom 𝐴 ∈ V ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | dmexd.1 | ⊢ ( 𝜑 → 𝐴 ∈ 𝑉 ) | |
| 2 | dmexg | ⊢ ( 𝐴 ∈ 𝑉 → dom 𝐴 ∈ V ) | |
| 3 | 1 2 | syl | ⊢ ( 𝜑 → dom 𝐴 ∈ V ) |