[Amy] invited her son [Dennis] to dinner, but not his wife [Emily].
('Amy', 'Emily')
[Amy] invited her son [Dennis] to dinner, but not his wife [Emily].
[{('Amy', 'daughter-in-law', 'Emily'): [('Amy', 'son', 'Dennis'), ('Dennis', 'wife', 'Emily')]}]
['son', 'wife']