Now I have a class X , the class has two characteristics A and B , A has values a1 and a2 , B has values b1 and b2 . In the configration , when I choose a1 for A then b2 cannot be chosen . To fulfill that I can creat a precondition dependency “ A <> 'A1' ” and assign it to the value b2 in ct04. But by doing this all configuration materials have characteristics A and B with other classes（not X）would be effected.
The question is how I can fulfill this purpose strict to the class X but not other classes？
PS：I donnot want to use overwritten in class.
Any help would be appreciated.