[eclipse 22]: compile(user, fd_domain). new_domain_var(X) :- printf("new domain variable created: %mw%n", [X]). user compiled traceable 88 bytes in 0.00 seconds yes. [eclipse 23]: X+Y #> T. new domain variable created: X[-10000000..10000000] new domain variable created: Y[-10000000..10000000] new domain variable created: T[-10000000..10000000]