ArrApp arrow arg _ HsFirstOrderApp False)
  = hsep [ppr_lexpr arg, arrowt, ppr_lexpr arrow]
ppr_expr (H
ppr_expr (HsArrApp arrow arg _ HsFirstOrderApp False)
  = hsep [ppr_lexpr arg, arrowt, ppr_lexpr arrow]
ppr_expr (HsArrApp arrow arg _ HsFirstOrderApp False)
  = hsep [ppr_lexpr arg, arrowt, ppr_lexpr arrow]