[Douglas] has a brother who is younger than him. The brother has a sister whose name is [Janet]. [Janet] met her grandfather, [Clarence], for ice cream.
('Douglas', 'Clarence')
[Douglas] has a brother who is younger than him. The brother has a sister whose name is [Janet]. [Janet] met her grandfather, [Clarence], for ice cream.
[{('Douglas', 'grandfather', 'Clarence'): [('Douglas', 'sister', 'Janet'), ('Janet', 'grandfather', 'Clarence')]}]
['sister', 'grandfather']