Metamath Proof Explorer


Theorem 0qs

Description: Quotient set with the empty set. (Contributed by Peter Mazsa, 14-Sep-2019)

Ref Expression
Assertion 0qs ⊢ ∅ / R = ∅

Proof

Step Hyp Ref Expression
1 df-qs ⊢ ∅ / R = y | ∃ x ∈ ∅ y = x R
2 rex0 ⊢ ¬ ∃ x ∈ ∅ y = x R
3 2 abf ⊢ y | ∃ x ∈ ∅ y = x R = ∅
4 1 3 eqtri ⊢ ∅ / R = ∅