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clrbit(+Number, +Index, -Result)

Result is Number with the Index'th bit cleared.
Non-negative integer.
A variable or integer.


Clear the Index'th bit in Number giving Result. The least significant bit has index zero. Two's complement representation is assumed. This predicate is used by the ECLiPSe compiler to expand evaluable arithmetic expressions. So the call to clrbit(Number, Index, Result) is equivalent to
    Result is clrbit(Number, Index)
which should be preferred.

In coroutining mode, if Number or Index are uninstantiated, the call is delayed until these variables are instantiated.

Modes and Determinism


(4) instantiation fault
Number or Index is not instantiated (non-coroutining mode only).
(5) type error
Result is a number but not an integer.
(5) type error
Number or Index is a number but not an integer.
(24) number expected
Number or Index is not of a numeric type.
(24) number expected
Result is neither a number nor a variable.


      clrbit(15, 3, 7).
      clrbit(40, 3, X).            gives X=32.
      X is clrbit(setbit(0,5),5).  gives X=0.

See Also

is / 2, setbit / 3, getbit / 3