// tests for method append()
boolean testAppend(Tester t) {
ILoI mt = new MT();
ILoI l1 = new Cons(1, mt);
ILoI l2 = new Cons(2, l1);
ILoI l3 = new Cons(2, mt);
ILoI l4 = new Cons(1, l3);
return t.checkExpect(l1.append(mt), l1)
&& t.checkExpect(l2.append(mt), l2)
&& t.checkExpect(l1.append(l3), l4);
}
