4.15 Declaring predicate properties
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Availability:built-in
Sourcenon_terminal :PredicateIndicator, ...
Sets the non_terminal attribute on the predicate. This indicates that the predicate implements a grammar rule. Currently, predicates that are exported using Name//Arity syntax are flagged as non-terminals. Ideally we should add this flag to any predicate created from the expansion of a --> rule, but that is difficult without breaking compatibility for programs that reason about expand_term/2,4.