Dialects are essential so you can specialize the brand new group of connectives of the

Dialects are essential so you can specialize the brand new group of connectives of the

  • Replacing NEWCONNECTIVE with zero or more new connective symbols. Dialects cannot keep the extension point.
  • Dropping no or even more of the predefined conjunctive symbols listed above. Languages dont change the fresh semantics of your own predefined connectives, but not.
  • Replacing NEWQUANTIFIER with zero or more new quantifier symbols. Dialects cannot keep the extension point.
  • Losing zero or maybe more of predetermined quantifier symbols in the above list. Although not, dialects don't redefine the brand new semantics of your own predefined quantifiers.

In the actual presentation syntax, we will be linearizing the predefined quantifier symbols and write them as Exists ?Xstep 1. Xn and Forall ?X1. Xn instead of Exists?X1. Xn and Forall?X1. Xn.

Every quantifier symbol has an associated list of variables that are bound by that quantifier. For the standard quantifiers Exists?X1. Xn and Forall?X1. Xn, the associated list of variables is ?X1. Xn.

RIF-FLD reserves the following symbols for standard aggregate functions: Min, Max, Number, Avg, Contribution, Prod, Place, and Purse. Aggregate functions also have an extension point, NEWAGGRFUNC, which must be actualized. Dialects can specialize the aforesaid set of aggregate functions by

  • Replacing NEWAGGRFUNC with zero or more new symbols for aggregate functions. Dialects cannot keep the extension point.
  • Shedding zero or even more of your own predetermined aggregate services listed above. Although not, dialects don't change the new semantics of the predefined aggregate characteristics.

As with most other extension circumstances, this isn't an authentic symbol in the alphabet, however, an effective placeholder you to definitely dialects are meant to make up for no or more actual new alphabet signs.

The symbol Naf represents default negation, which is used in rule languages with logic programming and deductive database semantics. Examples of default negation include Clark's negation-as-failure [Clark87], the well-founded negation [GRS91], and stable-model negation [GL88]. The name of the symbol Naf used here comes from negation-as-failure but in RIF-FLD this can refer to any kind of default negation.

The symbol Neg represents symmetric negation (as opposed to default negation, which is asymmetric because completely different inference rules are used to derive p and Naf p). Examples of symmetric negation include classical first-order negation, explicit negation, and strong negation [APP96].

=, #, and ## are used in formulas that define equality, class membership, and subclass relationships, respectively. The symbol -> is used in terms that have named arguments and in frame terms. The symbol Outside indicates that an atomic formula or a function term is defined externally (e.g., a built-in), Dialect is a directive used to indicate the dialect of a RIF document (for those dialects that require this), the symbols Feet and Prefix enable abridged representations of IRIs, and the symbol Import is an import directive. The Module directive is used to connect remote terms with the actual remote RIF documents.

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Finally, the symbol File is used for specifying RIF-FLD documents and the symbol Category is used to organize RIF-FLD formulas into collections. ?

dos.3 Symbol Rooms

These and other abbreviations was used as the prefixes throughout the compact URI-including notation [CURIE], an excellent notation for brief signal out of Iris [RFC-3987]. The particular meaning of this notation during the RIF is set within the [RIF-DTB].

The set of all constant symbols in a RIF dialect is partitioned into a number of subsets, called symbol spaces, which are used to represent XML Schema datatypes, datatypes defined in other W3C specifications, such as rdf:XMLLiteral, and to distinguish other sets of constants. All constant symbols have a syntax (and sometimes also semantics) imposed by the symbol space to which they belong.

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