I have 2 un-direct graphs, A and B. I know that the intersection between A and B is not empty. In detail, suppose that s and d are nodes in A and that b is a node in B. I know that some nodes in I(b) (neighbors of b) and also their edges belong to A, but NOT b. Because I am looking for a path from s to d passing through b, I wish to prove that is plausible to insert the b node and its “restricted” set of edges ( E(I(b) in A) to the path. Any hint? Suggestion?