expandConditional :: Expander -> TeXParser [Token]
expandConditional expand = do
  head <- conditionalHead expand
  value <- evaluateHead head
  runConditionalBody expand value
expandConditional :: Expander -> TeXParser [Token]
expandConditional expand = do
  head <- conditionalHead expand
  value <- evaluateHead head
  runConditionalBody expand value
expandConditional expand = do
  head <- conditionalHead expand
  value <- evaluateHead head
  runConditionalBody expand value