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# setbit(+Number, +Index, -Result)

Result is Number with the Index'th bit set.
*Number*
- Integer.
*Index*
- Non-negative integer.
*Result*
- Output: integer.

## Description

Set 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 setbit(Number, Index, Result) is
equivalent to
Result is setbit(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

### Exceptions

*(4) instantiation fault *
- Number or Index is not instantiated (non-coroutining mode only).
*(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.

## Examples

Result is setbit(0, 3). % gives Result = 8
Result is setbit(1, 8). % gives Result = 257
Result is setbit(setbit(0,3),5). % gives Result = 40

## See Also

is / 2, clrbit / 3, getbit / 3