learn the function h() such that:
if A (obj)--x (relation)--> B (obj)
=> h(A, x) = h(B)
h(A) = h(B, ~x)
if A --x1--> B --x2--> C
=> h(A, x1, x2) = h(B, x2) = h(C)
and if A --x2--> D -->x1--> C
=> h(A, x1, x2) != h(A, x2, x1) (order of relation matters)
not good, what if:
A --x--> B
A --x--> C
B --x--> D