English
In an R0 space, specialization is equivalent to inseparability: x specializes to y iff x and y are inseparable.
Русский
В R0-пространстве специализация эквивалентна inseparable: x специализируется на y тогда и только тогда, когда x и y inseparable.
LaTeX
$$$x \\mathrel{\\rhd} y \\iff Inseparable(x,y)$$$
Lean4
/-- In an R₀ space, the `Specializes` relation is symmetric, dot notation version. -/
theorem symm (h : x ⤳ y) : y ⤳ x :=
specializes_symmetric h