[Robert] made a grilled cheese for his son [Ronald]. [Ronald]'s brother [Mario] ate a salad. [Louis] enjoys talking to his sister and her son. Her son is [Mario]. [Ronald] went to the park with his father, [Robert].
('Ronald', 'Louis')
[Ronald] went to the park with his father, [Robert]. [Robert] made a grilled cheese for his son [Ronald]. [Ronald]'s brother [Mario] ate a salad. [Louis] enjoys talking to his sister and her son. Her son is [Mario].
[{('Ronald', 'uncle', 'Louis'): [('Ronald', 'father', 'Robert'), ('Robert', 'brother', 'Louis')]}, {('Robert', 'brother', 'Louis'): [('Robert', 'son', 'Mario'), ('Mario', 'uncle', 'Louis')]}, {('Robert', 'son', 'Mario'): [('Robert', 'son', 'Ronald'), ('Ronald', 'brother', 'Mario')]}]
['father', 'son', 'brother', 'uncle']