[Mary] and her husband, [Milton], went to a baseball game. [Nicholas], [Milton]'s father, was already there, holding their seats for them.
('Mary', 'Nicholas')
[Mary] and her husband, [Milton], went to a baseball game. [Nicholas], [Milton]'s father, was already there, holding their seats for them.
[{('Mary', 'father-in-law', 'Nicholas'): [('Mary', 'husband', 'Milton'), ('Milton', 'father', 'Nicholas')]}]
['husband', 'father']