Metamath Proof Explorer


Theorem qsexg

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

Proof

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