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

   Shifts Number1 left 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 if 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 --- Result is a number but not an integer.
     5 --- Number1 or Number2 is a number but not an integer.
    24 --- Number1 or Number2 is not of a numeric type.
    24 --- Result is neither a number nor a variable.

Examples
   
Success:
      <<(1, 3, 8).
Fail:
      <<(1, 2, 3).
Error:
      <<(A, 2, 6).              (Error 4).
      <<(6, 2.0, 24.0).         (Error 5).
      <<(4 + 2, 2, 24).         (Error 24).
      <<(5, 2, r).              (Error 24).





See Also
   is / 2
