Metamath Proof Explorer


Theorem qseq12d

Description: Equality theorem for quotient set, deduction form. (Contributed by Steven Nguyen, 30-Apr-2023)

Ref Expression
Hypotheses qseq12d.1 φA=B
qseq12d.2 φC=D
Assertion qseq12d φA/C=B/D

Proof

Step Hyp Ref Expression
1 qseq12d.1 φA=B
2 qseq12d.2 φC=D
3 qseq12 A=BC=DA/C=B/D
4 1 2 3 syl2anc φA/C=B/D