[Hugh] invited his brother, [Wesley], and his sister, [Lynn], over for dinner. [Lynn] could n't make it, but she sent her son [Thomas] over in her place so that the food would n't be wasted.
('Wesley', 'Thomas')
[Hugh] invited his brother, [Wesley], and his sister, [Lynn], over for dinner. [Lynn] could n't make it, but she sent her son [Thomas] over in her place so that the food would n't be wasted.
[{('Wesley', 'nephew', 'Thomas'): [('Wesley', 'sister', 'Lynn'), ('Lynn', 'son', 'Thomas')]}, {('Wesley', 'sister', 'Lynn'): [('Wesley', 'brother', 'Hugh'), ('Hugh', 'sister', 'Lynn')]}]
['brother', 'sister', 'son']