Unsigned numeric functions take unsigned intergers as arguments and returns the same integer type. The result of the carry and borrow functions cannot be implicitly cast to a real. For that you can use an explicit Single or Double type cast.

borrow(Integer, Integer)     Subtract the unsigned arguments and return one if
                             if underflow occured.  Otherwise zero is returned.

                             In a condition the borrow function is equivalent
                             to the unsigned less than (_<) comparator.

                             The Borrow function is used to perform multiple
                             precision subtraction and to check for underflow
                             on unsigned subtraction.



carry(Integer, Integer)      Add the unsigned arguments and return one if a
                             carry occured.  Otherwise zero is returned.

                             The Carry function is used to perform multiple
                             precision addition and to check for overflow on
                             unsigned addition.



positive(Integer)            Zero extend the argument to a wider integer or
                             real type.

                             Cell = positive( parcel{ Byte * 5 })

                                Sign extend the variable Byte to a Parcel.
                                Zero extend the parcel{} result to a Cell.

                    
                             Cell = parcel{ positive( Byte _* 5 })

                                Zero extend the variable Byte to a Parcel.
                                Sign extend the parcel{} result to a Cell.


                     Fault:  Any real value in the argument cannot be
                             implicitly cast to an integer.