Fix bug in adding ultimate bound

gem_stanley_teacher.py

@@ -197,7 +197,7 @@ class DTreeGEMStanleyGurobiTeacher(DTreeGurobiTeacherBase):
                                lb=0.0, ub=NEW_RAW_ANG_ERR_LIM)
         m.addConstr(new_lya_val == gp.norm(new_truth, float(self._norm_ord)))
 
-        m.addConstr(new_lya_val >= old_lya_val, name="Non-decreasing Error")  # Tracking error is non-decreasing
+        m.addConstr(new_lya_val >= bound_new_lya_val, name="Non-decreasing Error")  # Tracking error is non-decreasing
         m.update()
 
     def _add_objective(self) -> None: