r A_c in pivots
                ]

                # get max Z_tilde and update candidate accordingly
                tildes = [self._grow_rule_obj(X, y, r) for r in feature_candidates]
                if max(tildes) &gt; self._grow_rule_obj(X, y, candidate_rule):
                    candidate_rule = feature_candidates[
                        tildes.index(max(tildes))
                    ]

            preds = self._rule_predict(X, candidate_rule)
            negative_coverage = np.where((preds == y) &amp;