neurosynth/base/lexparser.py
def p_list_or(self, p):
        'list : list OR list'
        p[0] = pd.concat(
            [p[1], p[3]], axis=1).fillna(0.0).apply(self.func, axis=1)
def p_list_or(self, p):
        'list : list OR list'
        p[0] = pd.concat(
            [p[1], p[3]], axis=1).fillna(0.0).apply(self.func, axis=1)
list : list OR list