1.no B
2.No path from A->B
3.B has abstract super
4.B is a final class
5.B as an array object in A
6.a uses B as vector
7.A has two data members point to the same B object
8.A has B indirectly(A->D->B)
9.B is a super class of E, A contains E or B or both
10.a direct loop(A->B->A)
11.indirect loop with non-public E(A->E->B->A)
12.indirect loop with public E(A->E->B->F->A)
13.more than one indirect reference to B(A->E->B) & (A->D->B)
14.B has more than one supers(level >1)(E<-F<-B)
15.indirect level > 10 (A->E->F.....->B)


-----paths---------	
from A via B to C 
from A bypassing B to C 
from A bypassing X via B bypassing Y to C 
from A bypassing {X,X1} via {B,B1} bypassing {Y,Y1} to C 
from A bypassing {Q, ->X,y,Y, ->Y,x1,X1} via B bypassing {Y,Y1} to C 
from A to {B,C} 
{A-->B} 
empty path