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Predicate deterministic/1
Availability:built-in
deterministic(-Boolean)
Unifies its argument with true if no choice point exists that is more recent than the entry of the clause in which it appears. There are few realistic situations for using this predicate. It is used by the prolog/0 top level to check whether Prolog should prompt the user for alternatives. Similar results can be achieved in a more portable fashion using call_cleanup/2.
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LogicalCaptain said (2020-03-20T11:39:27):0 upvotes 0 0 downvotes
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Example:

ory :- format("1st clause:\n"),
       deterministic(D1),
       format("   Det at (1.1): ~w\n", [D1]),
       member(X,[alpha,bravo,charlie]),
       deterministic(D2),
       format("   Det at (1.2) with '~w': ~w\n", [X,D2]).
ory :- format("2nd clause:\n"),
       deterministic(D1),
       format("   Det at (2.1): ~w\n", [D1]).
ory :- format("3rd clause & done.").
?- bagof(_,ory,_).
1st clause:
   Det at (1.1): true
   Det at (1.2) with 'alpha': false
   Det at (1.2) with 'bravo': false
   Det at (1.2) with 'charlie': true
2nd clause:
   Det at (2.1): true
3rd clause & done.
true.

Implementation-wise, does this mean predicates not only return "true" or "false" but also an indicator saying "there are no more solutions, no need to call me again" if they can? It would make sense.