We are going to now identify the newest sentence structure utilizing the common EBNF notation

We are going to now identify the newest sentence structure utilizing the common EBNF notation

Until now, in order to establish the fresh syntax away from RIF-FLD i used “statistical English,” another type of English having communicating statistical significance, advice, etcetera. The second circumstances concerning EBNF notation is going to be kept in mind:


  • The new syntax away from RIF-FLD depends on the fresh trademark process which will be not framework-free, so EBNF cannot get which syntax truthfully. As a result, new EBNF sentence structure defines a strict superset out of RIF-FLD (not all algorithms that are derivable utilising the EBNF grammar was well-formed).
  • The EBNF syntax is not a concrete syntax: it does not http://datingranking.net/tr/talkwithstranger-inceleme 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 Label . Name, 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 tangible syntax just for selling and buying laws and regulations, hence syntax was XML-centered, obtained since a sophistication and you can serialization of your EBNF sentence structure thru new presentation-syntax-to-XML mapping having RIF-FLD.

Keeping the aforementioned at heart, the EBNF sentence structure is visible because the only a mediator between brand new analytical English together with XML. But not, in addition gets a succinct look at brand new syntax from RIF-FLD and thus they can be handy getting dialect designers and you may users exactly the same.

For each and every RIF-FLD formula and you will name is going to be prefixed having you to definitely recommended 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 , where IRI is a Unicode string in the form of an absolute IRI.

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 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 Frame 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].

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