If you use the dynamic data base, the clauses you assert might have
constraints associated with their variables. You should use
projecting_assert/1 instead of assert/1 in order to ensure that only
the relevant and projected constraints get stored in the data base.
| ?- {A+B=<33}, projecting_assert(test(A,B)).
{A+B=<33} ?
yes
| ?- listing(test).
test(A, B) :-
{A+B=<rat(33,1)}.
yes
| ?- test(A,B).
{A+B=<33} ?