# File lib/treetop/runtime/interval_skip_list/interval_skip_list.rb, line 64
  def delete(marker)
    range = ranges[marker]
    path_to_first_node = make_path
    first_node = find(range.first, path_to_first_node)

    cur_node = first_node
    cur_level = first_node.top_level
    while next_node_at_level_inside_range?(cur_node, cur_level, range)
      while can_ascend_from?(cur_node, cur_level) && next_node_at_level_inside_range?(cur_node, cur_level + 1, range)
        cur_level += 1
      end
      cur_node = unmark_forward_path_at_level(cur_node, cur_level, marker)
    end

    while node_inside_range?(cur_node, range)
      while can_descend_from?(cur_level) && next_node_at_level_outside_range?(cur_node, cur_level, range)
        cur_level -= 1
      end
      cur_node = unmark_forward_path_at_level(cur_node, cur_level, marker)
    end
    last_node = cur_node

    first_node.endpoint_of.delete(marker)
    if first_node.endpoint_of.empty?
      first_node.delete(path_to_first_node)
    end

    last_node.endpoint_of.delete(marker)
    if last_node.endpoint_of.empty?
      path_to_last_node = make_path
      find(range.last, path_to_last_node)
      last_node.delete(path_to_last_node)
    end
  end