Result is abs(Number)
which should be preferred for portability.
Result is the absolute value of Number, and of the same type.
In coroutining mode, if Number is uninstantiated, the call to abs/2 is delayed until this variable is instantiated.
Result is abs(1). % gives Result = 1
Result is abs(-5). % gives Result = 5
Result is abs(-6.2). % gives Result = 6.2
Result is abs(-0.6__-0.5). % gives Result = 0.5__0.6
Result is abs(-0.2__0.1). % gives Result = 0.0__0.2