public void Unify_lis_ne_lis()
{
ListTerm list1 = new ListTerm();
list1.Next = new ConstantTerm("ali");
list1.Next.Next = new ConstantTerm("[]");
ListTerm list2 = new ListTerm();
list2.Next = new ConstantTerm("ali");
list2.Next.Next = new ConstantTerm("foo");
Assert.IsFalse(list1.Unify(list2));
}