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Database
ZF (ZERMELO-FRAENKEL) SET THEORY
ZF Set Theory - add the Axiom of Union
Equivalence relations and classes
eceldmqs
Metamath Proof Explorer
Description: R -coset in its domain quotient. This is the bridge between A in
the domain and its block [ A ] R in its domain quotient. (Contributed by Peter Mazsa , 17-Apr-2019) (Revised by Peter Mazsa , 22-Nov-2025)
Ref
Expression
Assertion
eceldmqs
⊢ R ∈ V → A R ∈ dom ⁡ R / R ↔ A ∈ dom ⁡ R
Proof
Step
Hyp
Ref
Expression
1
resexg
⊢ R ∈ V → R ↾ dom ⁡ R ∈ V
2
eqid
⊢ dom ⁡ R = dom ⁡ R
3
ecelqsdmb
⊢ R ↾ dom ⁡ R ∈ V ∧ dom ⁡ R = dom ⁡ R → A R ∈ dom ⁡ R / R ↔ A ∈ dom ⁡ R
4
1 2 3
sylancl
⊢ R ∈ V → A R ∈ dom ⁡ R / R ↔ A ∈ dom ⁡ R