How to install clpq library in swi-prolog

Question

I am running SWI-Prolog (Multi-threaded, 64 bits, Version 7.2.3) on Debian Stable Linux. I want to install clpq package for Constraint Logic Programming.

However, it does not seem to be there on querying with pack_list command:

?- pack_list(clpq).
% Contacting server at http://www.swi-prolog.org/pack/query ... done
Warning: Unknown message: pack(search_no_matches(clpq))
true.

Where is the problem and how can it be solved? Thanks for your help.

Answer 1

I don't think you need to install anything. Just try:

?- use_module(library(clpq)).

You are using an ancient SWI-Prolog. Instructions on how to get something more up-to-date on Ubuntu (and probably Debian?):

http://www.swi-prolog.org/build/PPA.txt