[Mildred] invited her grandfather [James] to the movies last weekend. [James] and [Mildred] had a great time together. [Mildred] and [Pamela] are sisters who have one brother named [Irvin].
('Pamela', 'James')
[Mildred] and [Pamela] are sisters who have one brother named [Irvin]. [Mildred] invited her grandfather [James] to the movies last weekend. [James] and [Mildred] had a great time together.
[{('Pamela', 'grandfather', 'James'): [('Pamela', 'sister', 'Mildred'), ('Mildred', 'grandfather', 'James')]}, {('Pamela', 'sister', 'Mildred'): [('Pamela', 'brother', 'Irvin'), ('Irvin', 'sister', 'Mildred')]}]
['brother', 'sister', 'grandfather']