# File lib/ritex.rb, line 83
  def handle_mathml_markup what, tag, opts
    tag, opts = case tag
      when String
        [tag, opts]
      when Symbol
        a, b = MathML::MARKUP[tag]
        [a, [b, opts].flatten.compact.join(" ")]
      end
    unless opts.empty?
      "<#{tag} #{opts}>#{what}</#{tag}>"
    else
      "<#{tag}>#{what}</#{tag}>"
    end
  end