[m-users.] Tabling a semidet predicate

[Volker Wysk]

Hi!

I have a semidet predicate, and want to achieve termination with tabling.
Like this:


:- pred test(int::in) is semidet.
:- pragma minimal_model(test/1).

test(X) :- test(X).
test(1).
test(2).


This won't compile. I get this error message:


tab_semidet.m:010: Error: `:- pragma minimal_model' declaration not allowed
for
tab_semidet.m:010:   procedure with determinism `semidet'.
tab_semidet.m:010:   The pragma requested is only valid for the following
tab_semidet.m:010:   determinisms: multi and nondet.


However, I can work around this limitation like this:


:- pred test(int::in, {}::out) is nondet.
:- pragma minimal_model(test/2).

test(X, B) :- test(X, B).
test(1, {}).
test(2, {}).


I'm not sure if I understand this fully. Is this the way to go? Why the
restriction on the determinism category of the tabled predicate?

Cheers,
Volker
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