Semantic formations will always laid out regarding a particular place out of datatypes, denoted because of the DTS

Semantic formations will always laid out regarding a particular place out of datatypes, denoted because of the DTS

A semantic structure, I, is a tuple of the form
  • a related lay, known as well worth area, and you can
  • a great mapping throughout the lexical space of your icon room to help you the benefits room, named lexical-to-value-space mapping. ?

In a real dialect, DTS usually includes the latest datatypes supported by that dialect. All the RIF languages need certainly to keep the datatypes that will be numbered in Area Datatypes off [RIF-DTB]. Its worthy of spaces together with lexical-to-value-room mappings for these datatypes is discussed in the same part.

Although the lexical and the value spaces might sometimes look similar, one should not confuse them. Lexical spaces define the syntax of the constant symbols in the RIF language. Value spaces define the meaning of the constants. The lexical and the value spaces are often not even isomorphic. For example, 1.2^^xs:decimal and step one.20^^xs:decimal are two legal — and distinct — constants in RIF because step one.dos and 1.20 belong to the lexical space of xs:quantitative. However, these two constants are interpreted by the same element of the value space of the xs:quantitative type. Therefore, 1.2^^xs:quantitative = step one.20^^xs:decimal is a RIF tautology. Likewise, RIF semantics for datatypes implies certain inequalities. For instance, abc^^xs:string ? abcd^^xs:sequence is a tautology, since the lexical-to-value-space mapping of the xs:sequence type maps these two constants into distinct elements in the value space of xs:sequence.

step 3.cuatro Semantic Formations

The main help indicating an unit-theoretical semantics to have a logic-oriented vocabulary are defining the thought of a good semantic design. Semantic structures are accustomed to assign deends viewpoints in order to RIF-FLD formulas.

Definition (Semantic structure). C, IV, IF, INF, Ilist, Itail, Iframe, Isub, Iisa, I=, Iexterior, Iconjunctive, Itruth>. Here D is a non-empty set of elements called the domain of I. We will continue to use Const to refer to the set of all constant symbols and Var to refer to the set of all variable symbols. TV denotes the set of truth values that the semantic structure uses and DTS is a set of identifiers for benaughty profile datatypes.

A semantic structure, I, is a tuple of the form
  • Each pair <s,v> ? ArgNames ? D represents an argument/value pair instead of just a value in the case of a positional term.
  • The newest conflict to a term which have named objections is a restricted bag from argument/worth sets rather than a finite ordered series from effortless aspects.
  • Bags are used here because the order of the argument/value pairs in a term with named arguments is immaterial and the pairs may repeat: p(a->b good->b). (However, p(a->b a beneficial->b) is not equivalent to p(a->b), as we shall see later.)

To see why such repetition can occur, note that argument names may repeat: p(a->b a good->c). This can be understood as treating a as a bag-valued argument. Identical argument/value pairs can then arise as a result of a substitution. For instance, p(a->?An excellent good->?B) becomes p(a->b a->b) if the variables ?Good and ?B are both instantiated with the symbol b.

A semantic structure, I, is a tuple of the form
  • Ilist : D * > D
  • Itail : D + ?D > D

A semantic structure, I, is a tuple of the form
  • The function Ilist is injective (one-to-one).
  • The set Ilist(D * ), henceforth denoted Dlist , is disjoint from the value spaces of all data types in DTS.
  • Itail(a1, . ak, Ilist(ak+step one, . ak+meters)) = Ilist(a1, . ak, ak+step 1, . ak+m).

Note that the last condition above restricts Itail only when its last argument is in Dlist. If the last argument of Itail is not in Dlist, then the list is a general open one and there are no restrictions on the value of Itail except that it must be in D.

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