Metamath Proof Explorer


Theorem dmqseqeq1d

Description: Equality theorem for domain quotient set, deduction version. (Contributed by Peter Mazsa, 26-Sep-2021)

Ref Expression
Hypothesis dmqseqeq1d.1 φR=S
Assertion dmqseqeq1d φdomR/R=AdomS/S=A

Proof

Step Hyp Ref Expression
1 dmqseqeq1d.1 φR=S
2 dmqseqeq1 R=SdomR/R=AdomS/S=A
3 1 2 syl φdomR/R=AdomS/S=A