Re: Need advice for path research

[Timo Karjalainen]

Hi Gurvan,

> path(From, To, [From, To]) :- rel(From, To).
> path(From, To, [From | Tail]) :-
>    rel(From, Intermediate),
>    path(Intermediate, To, Tail).
>
>  How would you prevent an element to appear twice in the path?

You need to keep track of the nodes that you've visited already. Then  
you check that the Intermediate given by rel/2 is not in the set of  
already visited nodes.


--
TOK