[gecode-users] Reachability in a graph structure.

[Tobias Pankrath]

One of my errors was that I forgot g1_reach in the copy constructor, 
thus g1_reach showed up as the empty set in the output.

Didn't get it to work, yet. The contstraints are not specific enough, so 
I get reachable vertices that are not grounded in actual edges. Seems to 
be this issue

> I think that the element constraint does not exactly encode your purpose. You write:
>
> y ? g1_reach[x] and z ? g1_reach[y] ==>  z ? g1_reach[x]
>
> while your element constraint represents something like (if I am correct)
>
> y ? g1_reach[x] and z ? g1_reach[y] <=> z ? g1_reach[x]

Is http://cpgraph.info.ucl.ac.be/ an option? Is is not contained in the 
Contrib directory anymore.

Tobias