Is Your meaning logic/run* ? It will return all the possible values match the predication of the logic expression in it.🙂

I think he means that he doesn’t want to consider successful results which returned unbound variables… i.e. he wants to filter results which look like: _0. I think the answer is probably just to not to write programs that succeed with unground results. You could of course filter them out afterwards; but if you do that you might not know the difference between success/failure…

though I forget exactly what is returned in these cases

Rick you are correct about what I meant