Metamath Proof Explorer


Theorem dmqseqeq1

Description: Equality theorem for domain quotient. (Contributed by Peter Mazsa, 17-Apr-2019)

Ref Expression
Assertion dmqseqeq1 ⊢ R = S → dom ⁡ R / R = A ↔ dom ⁡ S / S = A

Proof

Step Hyp Ref Expression
1 dmqseq ⊢ R = S → dom ⁡ R / R = dom ⁡ S / S
2 1 eqeq1d ⊢ R = S → dom ⁡ R / R = A ↔ dom ⁡ S / S = A