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6 Predicate System

This system has maintenance concerns. 13

For a practical application of these concepts, see its use in the Program XML (see Specifying Predicates).

The predicate system determines the applicability of certain objects (like questions and assertions) by associating them with predicates. The domain of discourse (variables which may be quantified) is listed in Table 6.1.

What it means for some object to be applicable depends on the context.

TypePrefixDescription
ClassificationsNoneResults of applying an external classifier to the bucket (see Bucket).
Bucket Truth Predicateq:Whether the given name in the bucket (see Bucket) is non-empty and non-zero. The prefix ‘q:’ refers to its most common use case—questions (see Program UI).

Table 6.1: Predicate system domain of discourse

This system is limited to existential quantification over the domain of discourse. For other quantifiers and higher-order logic, defer to one of the systems that contributes to the domain of discourse, like the classifier.14

Predicates are usually specified in the Program XML (see Specifying Predicates) and compiled into the program (see Program).


Footnotes

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New programs (using the old incarnation of TAME) use the classifier embedded into the rater by TAME. Old ones, however, still use the Global Classifier. This system isn’t as well tested as TAME’s—which needs to work properly for the sake of calculating premium—and has suffered from a number of bugs in the past.

The solution is to migrate all programs to TAME and remove that old code.

(14)

This is usually TAME. The Program XML also supports inline classifications with TAME’s syntax (see Specifying Predicates).