```python
>>> 'hello' in Pw.keys() >>> Pwords(['hello'])
True -4.25147684171819
->>> 'inigo' in Pw.keys() >>> Pwords(['hello', 'my'])
+>>> 'inigo' in Pw >>> Pwords(['hello', 'my'])
True -6.995724679281423
->>> 'blj' in Pw.keys() >>> Pwords(['hello', 'my', 'name'])
+>>> 'blj' in Pw >>> Pwords(['hello', 'my', 'name'])
False -10.098177451501074
>>> Pw['hello'] >>> Pwords(['hello', 'my', 'name', 'is'])
-4.25147684171819 -12.195018236240843