It must be indexed one to [RIF-DTB] raises plenty of mainly based-within the equality predicates into the various investigation types (for example,
- Syntactic framework. This framework represent this new systems having specifying the fresh new authoritative demonstration sentence structure of RIF logic dialects of the focusing the fresh demonstration syntax of structure. This new demonstration sentence structure can be used when you look at the RIF to help you determine the newest semantics of the languages and to instruct area of the records having instances. This syntax isn’t intended to be a concrete sentence structure getting the new dialects; they renders away facts such as the delimiters of the numerous syntactic components, parenthesizing, precedence away from providers, and so on. While the RIF are an interchange structure, it spends XML as its only concrete sentence structure.
- Semantic build. This new semantic design describes the newest systems which might be useful for specifying brand new types of RIF reasoning languages.
- XML serialization structure. That it build represent the general prices one reasoning languages should be use in indicating the concrete XML-dependent syntaxes. Each dialect, their real XML sentence structure try a by-product of your own dialect’s presentation syntax. It can be named good serialization of this sentence structure.
- Constants and you can variables. This type of terminology are typical to the majority logic languages.
- Positional terms. These types of conditions are generally included in earliest-order logic. RIF-FLD talks of positional words inside the a somewhat even more standard way when you look at the order make it possible for languages that have high-order sentence structure, such as for instance HiLog [CKW93] and you will Relfun [RF99].
- Words that have titled arguments. These are like positional words other than per conflict from a beneficial title is named as well as the purchase of the objections is immaterial. Words with named objections generalize the idea of rows when you look at the relational dining tables, where column headings correspond to dispute brands.
- Lists. These bookofmatches terminology correspond to lists in reasoning programming, and generally are included in the essential Logic Dialect. Minimal systems of those terms and conditions are utilized throughout the Center Dialect and Creation Legislation Dialect.
- Structures. A frame identity represents an assertion in the an object and its own properties. These words match molecules off F-logic [KLW95]. There clearly was syntactic similarity ranging from terms and conditions which have called arguments and you can frames, due to the fact properties (otherwise functions) from an object resemble entitled objections. Although not, the latest semantics of these conditions differ (find Area Semantic Formations).
- Category. Such words are acclimatized to define this new subclass and you can group subscription dating. There have been two types of classification terms: subscription words and you may subclass terms. Instance frames, such terminology was basically lent regarding F-reasoning [KLW95].
- Equality. Such terminology are widely used to associate almost every other conditions.
pred:numeric-equivalent or pred:boolean-equal). Those predicates have fixed interpretations, which coincide with the interpretation of the equality terms defined in this document when the latter are evaluated over data types. General use of equality terms is supported in systems such as FLORA-2 [FL2], and special cases are also allowed in Relfun [RF99].
Terms are then used to define several types of RIF-FLD formulas. RIF dialects can choose to permit all or some of the aforesaid categories of terms. In addition, RIF-FLD introduces extension points, one of which allows the introduction of new kinds of terms. An extension point is a keyword that is not a syntactic construct per se, but a placeholder that is supposed to be replaced by specific syntactic constructs of an appropriate kind. RIF-FLD defines several types of extension points: symbols (NEWSYMBOL), connectives (), quantifiers (NEWQUANTIFIER), aggregate functions (NEWAGGRFUNC), and terms (NEWTERM).
Yet not, outside of the investigation designs, the fresh interpretation of the equality terms can vary that will be determined because of the items in RIF records
Symbol spaces partition the fresh new group of non-analytical icons one to correspond to individual constants, predicates, and procedures, and each partition is then considering its semantics. A symbol room keeps an identifier and you may a lexical area, and this defines the “shape” of your own icons because symbol place. Certain symbol places into the RIF are widely used to select Web organizations in addition to their lexical place includes strings you to definitely syntactically seem like internationalized resource identifiers [RFC-3987], otherwise Iris (e.grams., Most other symbol spaces are accustomed to show the latest datatypes necessary for RIF (such as,