chap6\chap6_1.m .....\chap6_2.mdl .....\chap6_2plant.m .....\chap6_2s.m .....\chap6_3.m .....\chap6_4.mdl .....\chap6_4s1.m .....\chap6_4s2.m .....\chap6_5.m chap6