def ol_depth(node)
      depth = node.ancestors("ul, ol").size + 1
      type = :alphabet
      type = :arabic if [2, 7].include? depth
      type = :roman if [3, 8].include? depth
      type = :alphabet_upper if [4, 9].include? depth
      type = :roman_upper if [5, 10].include? depth
      ol_style(type)
    end
def ol_depth(node)
      depth = node.ancestors("ul, ol").size + 1
      type = :alphabet
      type = :arabic if [2, 7].include? depth
      type = :roman if [3, 8].include? depth
      type = :alphabet_upper if [4, 9].include? depth
      type = :roman_upper if [5, 10].include? depth
      ol_style(type)
    end
We don't really want users to specify type of ordered list;
 we will use a fixed hierarchy as practiced by ISO (though not
 fully spelled out): a) 1) i) A) I)