
>>(+Number1, +Number2, -Result)

   Shifts Number1 right arithmetically by Number2 bits and unifies the
resulting value with Result.



Arguments
   Number1             Integer.
   Number2             Integer.
   Result              A variable or integer.

Type
   Arithmetic

Description
   This predicate is used by the ECLiPSe compiler to expand evaluable
   arithmetic expressions.  So the call to >>(Number1, Number2, Result) is
   equivalent to

    Result is Number1 >> Number2

    which should be preferred for portability.

   The shift behaves as an arithmetic (signed) shift operating on an unlimited
   length two's complement representation.  Shifting by a negative amount is
   the same as shifting by the same positive amount in the other direction.

   In coroutining mode, if Number1 or Number2 are uninstantiated, the call
   to >>/3 is delayed until these variables are instantiated.




Modes and Determinism
   >>(+, +, -) is det

Exceptions
     4 --- Number1 or Number2 is not instantiated (non-coroutining mode    only).
     5 --- Number1 or Number2 is a number but not an integer.
    24 --- Number1 or Number2 is not of a numeric type.

Examples
   
Success:
      >>(8, 3, 1).
      >>(17, 3, X).          (gives X = 2)
Fail:
      >>(1, 2, 3).
      >>(16, 2.0, 4.0).
      >>(5, 2, r).
Error:
      >>(A, 2, 6).              (Error 4).
      >>(4 + 12, 2, 4).         (Error 24).





See Also
   is / 2
