let cvt_binop = function
    CTTbinTimes       -> ILbinTimes
  | CTTbinDiv         -> ILbinDiv
  | CTTbinPlusVV      -> ILbinPlusVV
  | CTTbinMinusVV     -> ILbinMinusVV
  | CTTbinPostPlusVV  -> ILbinPlusVV
  | CTTbinPostMinusVV -> ILbinMinusVV
  | CTTbinPlusPV      -> ILbinPlusPV
  | CTTbinMinusPP     -> ILbinMinusPP
  | CTTbinMinusPV     -> ILbinMinusPV
  | CTTbinPostPlusPV  -> ILbinPlusPV
  | CTTbinPostMinusPV -> ILbinMinusPV
  | CTTbinModulo      -> ILbinModulo
  | CTTbinLshift      -> ILbinLshift
  | CTTbinRshift      -> ILbinRshift
  | CTTbinLogAnd      -> ILbinLogAnd
  | CTTbinLogOr       -> ILbinLogOr
  | CTTbinIntAnd      -> ILbinIntAnd
  | CTTbinIntOr       -> ILbinIntOr
  | CTTbinIntXor      -> ILbinIntXor
  | CTTbinLessThan    -> ILbinLessThan
  | CTTbinLessEqual   -> ILbinLessEqual
  | CTTbinGtrThan     -> ILbinGtrThan
  | CTTbinGtrEqual    -> ILbinGtrEqual
  | CTTbinEqual       -> ILbinEqual
  | CTTbinNotEqual    -> ILbinNotEqual