[Louis] took his son [Michael] to the zoo yesterday because he took his daughter [Nicole] last week [Nicole] spent the whole month of January at her grandfather [Harold]'s house. [Louis] was delighted to watch his son [Michael] steal third base in the Championship baseball game.
('Louis', 'Harold')
[Louis] was delighted to watch his son [Michael] steal third base in the Championship baseball game. [Louis] took his son [Michael] to the zoo yesterday because he took his daughter [Nicole] last week [Nicole] spent the whole month of January at her grandfather [Harold]'s house.
[{('Louis', 'father', 'Harold'): [('Louis', 'son', 'Michael'), ('Michael', 'grandfather', 'Harold')]}, {('Michael', 'grandfather', 'Harold'): [('Michael', 'sister', 'Nicole'), ('Nicole', 'grandfather', 'Harold')]}, {('Michael', 'sister', 'Nicole'): [('Michael', 'father', 'Louis'), ('Louis', 'daughter', 'Nicole')]}]
['son', 'father', 'daughter', 'grandfather']