English
For any a in α, the relation s1 holds between the quotient mk'' a and its out value.
Русский
Для любого a ∈ α отношение s1 держится между mk'' a и его значением out.
LaTeX
$$$s_1( (\\operatorname{Quotient.mk''} a : \\operatorname{Quotient}(s_1)).\\mathrm{out}, a )$$$
Lean4
theorem mk_out' (a : α) : s₁ (Quotient.mk'' a : Quotient s₁).out a :=
Quotient.exact (Quotient.out_eq _)