Suggestion: Create mode of conversion back

[carlos-adir]

A set with one value like {0.25} is transformed into a SingleValue instance.

The suggestion is be able to transform the SingleValue back into a set with one element:

>>> from rbool import *
>>> myset = {0.25}
>>> single = from_any(myset)
>>> single
SingleValue(0.25)
>>> otherset = set(single)
TypeError: 'SingleValue' object is not iterable

The solution is to make SingleValue iterable with only one value:

class SingleValue:
    ...

    def __iter__(self) -> Real:
        yield self.internal