[Linda] is a sister of [Robert]. [Clarence] took his grandson [Robert] to the zoo last Saturday. They had a good time.
('Clarence', 'Linda')
[Clarence] took his grandson [Robert] to the zoo last Saturday. They had a good time. [Linda] is a sister of [Robert].
[{('Clarence', 'granddaughter', 'Linda'): [('Clarence', 'grandson', 'Robert'), ('Robert', 'sister', 'Linda')]}]
['grandson', 'sister']