[Glen] is a man with a brother named [Michael]. [Mary] went car shopping with her brother [Michael].
('Glen', 'Mary')
[Glen] is a man with a brother named [Michael]. [Mary] went car shopping with her brother [Michael].
[{('Glen', 'sister', 'Mary'): [('Glen', 'brother', 'Michael'), ('Michael', 'sister', 'Mary')]}]
['brother', 'sister']