[Robert] and [Louis] are twin brothers. [Louis] has two children, [Jennifer] and [Samuel], and [Robert] does n't have any [Pedro] ran over to see his uncle [Samuel].
('Robert', 'Pedro')
[Robert] and [Louis] are twin brothers. [Louis] has two children, [Jennifer] and [Samuel], and [Robert] does n't have any [Pedro] ran over to see his uncle [Samuel].
[{('Robert', 'brother', 'Pedro'): [('Robert', 'brother', 'Louis'), ('Louis', 'brother', 'Pedro')]}, {('Louis', 'brother', 'Pedro'): [('Louis', 'son', 'Samuel'), ('Samuel', 'uncle', 'Pedro')]}, {('Louis', 'son', 'Samuel'): [('Louis', 'daughter', 'Jennifer'), ('Jennifer', 'brother', 'Samuel')]}]
['brother', 'daughter', 'brother', 'uncle']