As yet, to specify the brand new sentence structure out of RIF-FLD we made use of “analytical English,” a special variety of English for communicating statistical meanings, examples, etcetera. The next circumstances concerning EBNF notation will be kept in mind:
LOCATOR
- The brand new sentence structure away from RIF-FLD utilizes the fresh new signature apparatus that’s maybe not context-totally free, thus EBNF will not bring that it syntax truthfully. Because of this, the brand new EBNF grammar represent a rigorous superset away from RIF-FLD (not totally all algorithms which can be derivable using the EBNF sentence structure are well-formed).
- The EBNF syntax is not a concrete syntax: it does not address the details of how constants (defined in [RIF-DTB]) and variables are represented, and it is not sufficiently precise about the delimiters and escape symbols. White space is informally used as a delimiter, and is implied in productions that use Kleene star. For instance, TERM* is to be understood as Term Identity . Term, where each ‘ ‘ abstracts from one or more blanks, tabs, newlines, etc. This is done intentionally since RIF’s presentation syntax is used as a tool for specifying the semantics and for illustration of the main RIF concepts through examples.
- RIF defines a real sentence structure just for selling and buying regulations, and this syntax is XML-dependent, received since the a sophistication and you can serialization of the EBNF syntax via this new presentation-syntax-to-XML mapping to possess RIF-FLD.
Remaining these planned, new EBNF sentence structure is visible since only an intermediary ranging from the mathematical English plus the XML. Although not, in addition it gets a concise look at the new sentence structure out-of RIF-FLD and therefore can be useful having dialect painters and profiles the same.
For each RIF-FLD algorithm and you may name will be prefixed which have one elective annotation
The RIF-FLD presentation syntax does not commit to any particular vocabulary and permits arbitrary sequences of Unicode characters in constant symbols, argument names, and variables. Such sequences are denoted with UNICODESTRING in the above syntax. Constant symbols have this form: "UNICODESTRING"^^SYMSPACE, where SYMSPACE is a ANGLEBRACKIRI or CURIE that represents the identifier of the symbol space of the constant. UNICODESTRING, ANGLEBRACKIRI, and CURIE are defined in Section Shortcuts for Constants in RIF’s Presentation Syntax of [RIF-DTB]. Constant symbols can also have several shortcut forms, which are represented by the non-terminal CONSTSHORT. These shortcuts are also defined in the same section of [RIF-DTB]. One of them is the CURIE shortcut, which is used in the examples in this document. Names are Unicode character sequences that form valid XML NCNames [XML-Names]. Variables are composed of Names prefixed with a ?-sign.
, which is used in several places in the grammar, is a non-terminal whose definition is left to the dialects. It is intended to specify the protocol by which external sources, remote modules, and imported RIF documents are located. This must include the basic form
The symbols NEWCONNECTIVE, NEWQUANTIFIER, NEWAGGRFUNC, and NEWTERM are RIF-FLD extension points. They are not actual symbols in the alphabet. Instead, dialects are supposed to replace NEWCONNECTIVE, NEWQUANTIFIER, and NEWAGGRFUNC, by zero or more actual new symbols, while NEWTERM is to be replaced https://datingranking.net/tr/woosa-inceleme/ by zero or more new kinds of terms. Note that the extension point NEWSYMBOL is not shown in the EBNF grammar completely avoids mentioning the alphabet of the language (which is infinite).
IRIMETA, for identification and metadata. IRIMETA is represented using (*. *)-brackets that contain an optional rif:iri constant as identifier followed by an optional Body type or cones as metadata. One such specialization is '"' IRI '"^^' 'rif:iri' from the Const production, where IRI is a sequence of Unicode characters that forms an internationalized resource identifier as defined by [RFC-3987].