fact: Definition lower_convex_hull_points pts := match pts with | [] => None | [pt₁] => None | pt₁ :: pt₂ :: pts₂ => let ms := minimise_slope pt₁ pt₂ pts₂ in Some {| ini_pt := ini_pt ms; fin_pt := fin_pt ms; oth_pts := oth_pts ms |} end.
imports: Utf8 QArith List Slope_base