nltk.PCFG.leftcorner_parents¶

PCFG.leftcorner_parents(cat)¶

Return the set of all nonterminals for which the given category is a left corner. This is the inverse of the leftcorner relation.

Parameters:	cat (Nonterminal) – the suggested leftcorner
Returns:	the set of all parents to the leftcorner
Return type:	set(Nonterminal)