fact: Definition update_open_cell_top (c : cell) (new_high : edge) (e : event) := if outgoing e is [::] then let newptseq := [:: Bpt (p_x (point e)) (pvert_y (point e) new_high) & left_pts c] in ([::], Bcell newptseq (right_pts c) (low c) new_high) else match opening_cells_aux (point e) (sort edge_below (outgoing e)) (low c) new_high with | ([::], lc) => ([::], lc) | (f :: q, lc) => (set_left_pts f (point e :: behead (left_pts c)) :: q, lc) end.
imports: mathcomp(all_ssreflect) ZArith QArith List String OrderedType OrderedTypeEx FMapAVL