Description: A quotient set exists. (Contributed by FL, 19-May-2007) (Revised by Mario Carneiro, 9-Jul-2014)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | qsexg | ⊢ ( 𝐴 ∈ 𝑉 → ( 𝐴 / 𝑅 ) ∈ V ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | df-qs | ⊢ ( 𝐴 / 𝑅 ) = { 𝑦 ∣ ∃ 𝑥 ∈ 𝐴 𝑦 = [ 𝑥 ] 𝑅 } | |
| 2 | abrexexg | ⊢ ( 𝐴 ∈ 𝑉 → { 𝑦 ∣ ∃ 𝑥 ∈ 𝐴 𝑦 = [ 𝑥 ] 𝑅 } ∈ V ) | |
| 3 | 1 2 | eqeltrid | ⊢ ( 𝐴 ∈ 𝑉 → ( 𝐴 / 𝑅 ) ∈ V ) |