English
An upper set is Lawson open if and only if it is Scott open, in a setting with isLawson and isScott assumptions.
Русский
В условии IsLawson и IsScott верхнее множество открыто в Lawson тогда и только тогда когда оно открыто в Scott.
LaTeX
$$$IsOpen_{lawson}(s) \iff IsOpen_{scott}(s)$ under IsUpperSet s and lawson/scott assumptions$$
Lean4
/-- An upper set is Lawson open if and only if it is Scott open -/
theorem lawsonOpen_iff_scottOpen_of_isUpperSet' (s : Set α) (h : IsUpperSet s) : IsOpen[L] s ↔ IsOpen[S] s :=
by
rw [@IsLawson.topology_eq_lawson α _ L _, @IsScott.topology_eq α univ _ S _]
exact lawsonOpen_iff_scottOpen_of_isUpperSet h