Re: [eclipse-clp-users] error

On 13/10/2012 09:57, Anshu Shankar Prasad wrote:
> while compiling the below program I get an error like this
>   instantiation fault in +(_593, 1, _597)
> what is this mean and what should I do to remove this.Help me asap..
> here is my program
> :-lib(ic).
> :-lib(branch_and_bound).
>   solve(N,X):-
>   dim(X, [N]),
>   X[1..N] :: 1..49,
>   %Z :: 1..49,
>   (
>     for(I,1,N),param(X,N) do
>     (
>       for(J,I,N),param(X,I) do
>      (
>         for(K,J+1,N),param(X,J) do
>         X[K]-X[I]-X[J]#\=0
>       )
>      )
>    ),
> X =.. [_|Vars],
> labeling(Vars).

When you compile this code, you get several "singleton" warnings,
which you should not ignore:

*** Warning: Singleton local variable I in do-loop, maybe param(I) missing?
File prasad.ecl, line 15: Singleton variable I
*** Warning: Singleton local variable N in do-loop, maybe param(N) missing?
*** Warning: Singleton local variable I in do-loop (not used in loop body)
File prasad.ecl, line 13: Singleton variable N
prasad.ecl compiled 616 bytes in 0.02 seconds

The param's are needed because every do-loop has its own namespace for
variables.  If you want a variable from outside a loop to be visible
inside, you must "pass it in" as a param.  You forgot to pass the
N into the 2nd loop, and the I into the 3rd loop, viz.

  (
    for(I,1,N),param(X,N) do
    (
      for(J,I,N),param(X,I,N) do
     (
        for(K,J+1,N),param(X,I,J) do

        X[K]-X[I]-X[J]#\=0
      )
     )
   ),


> one more I query i have tha If a optimization problem has more than one solution how could I get
> all of its solution. Till now for getting multiple  solution of  a COP I am doing that by
> converting the problem it into a CSP.please tell me the other way to doing this.Expalin with example.
> So please tell me if there is  an nother method

See these earlier postings on the subject:
http://eclipseclp.org/archive/eclipse-clp-users/1524.html
http://eclipseclp.org/archive/eclipse-clp-users/0468.html


Cheers,
Joachim