D-rule

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'''D-rules''' (declaration rules) are used to make statements inside the UNL<sup>arium</sup> framework. They are used to assign priorities (disambiguation rules), to map attributes and relations (mapping rules) and to state identities (replacement rules).
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'''D-rules''' (disambiguation rules) are used to prevent wrong lexical choices, to provoke best matches and to check the consistency of graphs, trees and lists. Differently from [[Grammar|T-rules]], they do not provoke transformations, but induce or block them, by assigning priorities to natural language phenomena.
  
 
== Syntax ==
 
== Syntax ==
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D-rules are always composed of two fields, which are separated by "=". They are always ended by a ";".
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D-rules follow the general syntax:
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<DEFINIENDUM> = <DEFINIENS>;
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Where:<br />
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*<DEFINIENDUM>, the term to be defined, may be:
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**an attribute or a value of an attribute, of UNL (@pl, @male, @future) or of NL (POS, NOU, GEN, MCL, etc);
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**a node, to be represented as a "string" (between parentheses) or as a [lemma] (between square brackets);
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**a relation, either syntactic or semantic (such as "agt", "obj", "VS", "XP"), with the corresponding constituents; or
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**a sequence of attributes, nodes and relations.
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*<DEFINIENS>, the definition, may be:
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**an attribute or a value of an attribute, of UNL (@pl, @male, @future) or of NL (POS, NOU, GEN, MCL, etc);
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**a node, to be represented as a "string" (between parentheses) or as a [lemma] (between square brackets);
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**a relation, either syntactic or semantic (such as "agt", "obj", "VS", "XP"), with the corresponding constituents;
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**a sequence of attributes, nodes and relations; or
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**a numeric value indicating the degree of certainty, ranging from 0 (=impossible) to 255 (=necessary).
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== Types of D-rule ==
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STATEMENT=P;
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There are three main types of D-rule:
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*'''Disambiguation rules''' are used to state priorities.
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*'''Mapping rules''' are used to state correspondences between UNL and NL.
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*'''Replacement rules''' are used to state correspondences inside UNL or NL.
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=== Disambiguation rules ===
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Where<br />
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Disambiguation rules are used to state priorities. They follow the general syntax:
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STATEMENT is the left side (condition) of a [[L-rule]] or a [[S-rule]]; and<br />
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<DEFINIENDUM> = VALUE;
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P, which can range from 0 (impossible) to 255 (necessary), is the probability of occurrence of the STATEMENT<br />
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Where <VALUE> is a numeric value that may range from 0 (impossible, or FALSE) to 255 (necessary).
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Disambiguation rules normally apply over the left side of [[L-rule]]s and [[S-rule]]s.
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==== Examples of disambiguation rules ====
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== Examples ==
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*("the",ART)("a",ART)=0; (It's not possible that the article "a" follows the article "the")  
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*List structures
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*("afraid",ADJ)(BLK)("of",PRE)=255; (It's absolutely necessary that the preposition "of" follows the adjective "afraid" after a blank space).
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**(ART)(BLK)(VER)=0; (an article (ART) may not precede a verb (VER))
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*VH(NOU)=0; (It's not possible that the head of a verbal phrase be a noun)
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**(ART)(BLK)(NOU)=255; (articles (ART) always precede nouns (NOU))
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*VH(VER)=255; (It's absolutely necessary that the head of a verbal phrase be a verb)
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*Syntactic structures
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**agt(VER;ADJ)=0; (an adjective (ADJ) may not be an agent (agt) of a verb (VER))
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=== Mapping rules ===
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**agt(VER;NOU)=255; (agents (agt) of verbs (VER) are always nouns (NOU))
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Mapping rules are used to state correspondences between UNL and NL. They follow the general syntax:
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**VS(VER;ADJ)=0; (an adjective (ADJ) may not be an specifier (VS) of a verb (VER))
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<DEFINIENDUM> = <DEFINIENS>;
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**NS(NOU;DET)=255; (determiners (DET) are always specifiers (NS) of nouns (NOU))
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Where <DEFINIENDUM> is an element of UNL and <DEFINIENS> is an element of NL, or vice-versa.
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==== Examples of mapping rules ====
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*From UNL to NL
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**@pl = PLR;
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**@past = PAS;
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**@passive = PSV;
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**@male = MCL;
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**@past,@progressive = PAS,PGS;
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*From NL to UNL
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**PLR = @pl;
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**PAS = @past
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**MCL = @male
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**PAS,PGS = @past.@progressive
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=== Replacement rules ===
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Replacement rules are used to state correspondences inside UNL or NL. They follow the general syntax:
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<DEFINIENDUM> = <DEFINIENS>;
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Where <DEFINIENDUM> and <DEFINIENS> are both elements of UNL, or are both elements of NL.<br />
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Replacement rules are mainly used to avoid redundancy and unnecessary proliferation of rules.
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==== Examples of replacement rules ====
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*Inside UNL
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**@dual = @pl; (replace the attribute @dual by the attribute @pl)
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*Inside NL
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**DUA = PLR; (replace the attribute DUA by the attribute PLR)
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Revision as of 09:23, 27 March 2010

D-rules (disambiguation rules) are used to prevent wrong lexical choices, to provoke best matches and to check the consistency of graphs, trees and lists. Differently from T-rules, they do not provoke transformations, but induce or block them, by assigning priorities to natural language phenomena.

Syntax

D-rules follow the general syntax: 

STATEMENT=P;

Where
STATEMENT is the left side (condition) of a L-rule or a S-rule; and
P, which can range from 0 (impossible) to 255 (necessary), is the probability of occurrence of the STATEMENT

Examples

  • List structures
    • (ART)(BLK)(VER)=0; (an article (ART) may not precede a verb (VER))
    • (ART)(BLK)(NOU)=255; (articles (ART) always precede nouns (NOU))
  • Syntactic structures
    • agt(VER;ADJ)=0; (an adjective (ADJ) may not be an agent (agt) of a verb (VER))
    • agt(VER;NOU)=255; (agents (agt) of verbs (VER) are always nouns (NOU))
    • VS(VER;ADJ)=0; (an adjective (ADJ) may not be an specifier (VS) of a verb (VER))
    • NS(NOU;DET)=255; (determiners (DET) are always specifiers (NS) of nouns (NOU))
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