Description: Sethood of the domain quotient under sethood of R . (Contributed by Peter Mazsa, 2-Nov-2018)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | dmqsex | ⊢ ( 𝑅 ∈ 𝑉 → ( dom 𝑅 / 𝑅 ) ∈ V ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | dmexg | ⊢ ( 𝑅 ∈ 𝑉 → dom 𝑅 ∈ V ) | |
| 2 | qsexg | ⊢ ( dom 𝑅 ∈ V → ( dom 𝑅 / 𝑅 ) ∈ V ) | |
| 3 | 1 2 | syl | ⊢ ( 𝑅 ∈ 𝑉 → ( dom 𝑅 / 𝑅 ) ∈ V ) |