def __getitem__(self, variable):
        assert isinstance(variable, Variable)

        intermediate = self.d[variable]
        while intermediate:
            try:
                intermediate = self.d[intermediate]
            except KeyError:
                return intermediate
Return the expression to which 'variable' is bound
dataset/ETHPy150Open nltk/nltk/nltk/inference/resolution.py/BindingDict.__getitem__