[John] took his mother [Lillian] a new pot for her flowers. [Douglas] is a man with a brother named [John].
('Douglas', 'Lillian')
[Douglas] is a man with a brother named [John]. [John] took his mother [Lillian] a new pot for her flowers.
[{('Douglas', 'mother', 'Lillian'): [('Douglas', 'brother', 'John'), ('John', 'mother', 'Lillian')]}]
['brother', 'mother']