D-rule

Revision as of 18:12, 26 March 2010

D-rules (declaration rules) are used to make statements inside the UNL^arium framework. They are used to assign priorities (disambiguation rules), to map attributes and relations (mapping rules) and to state identities (replacement rules).

Syntax

D-rules are always composed of two fields, which are separated by "=". They are always ended by a ";".

<DEFINIENDUM> = <DEFINIENS>;

Where:

• <DEFINIENDUM>, the term to be defined, may be:
  • an attribute or a value of an attribute, of UNL (@pl, @male, @future) or of NL (POS, NOU, GEN, MCL, etc);
  • a node, to be represented as a "string" (between parentheses) or as a [lemma] (between square brackets);
  • a relation, either syntactic or semantic (such as "agt", "obj", "VS", "XP"), with the corresponding constituents; or
  • a sequence of attributes, nodes and relations.
• <DEFINIENS>, the definition, may be:
  • an attribute or a value of an attribute, of UNL (@pl, @male, @future) or of NL (POS, NOU, GEN, MCL, etc);
  • a node, to be represented as a "string" (between parentheses) or as a [lemma] (between square brackets);
  • a relation, either syntactic or semantic (such as "agt", "obj", "VS", "XP"), with the corresponding constituents;
  • a sequence of attributes, nodes and relations; or
  • a numeric value indicating the degree of certainty, ranging from 0 (=impossible) to 255 (=necessary).

Types of D-rule

There are three main types of D-rule:

• Disambiguation rules are used to state priorities.
• Mapping rules are used to state correspondences between UNL and NL.
• Replacement rules are used to state correspondences inside UNL or NL.

Disambiguation rules

Disambiguation rules are used to state priorities. They follow the general syntax:

<DEFINIENDUM> = VALUE;

Where <VALUE> is a numeric value that may range from 0 (impossible, or FALSE) to 255 (necessary). Disambiguation rules normally apply over the left side of L-rules and S-rules.

Examples of disambiguation rules

• ("the",ART)("a",ART)=0; (It's not possible that the article "a" follows the article "the")
• ("afraid",ADJ)(BLK)("of",PRE)=255; (It's absolutely necessary that the preposition "of" follows the adjective "afraid" after a blank space).
• VH(NOU)=0; (It's not possible that the head of a verbal phrase be a noun)
• VH(VER)=255; (It's absolutely necessary that the head of a verbal phrase be a verb)

Mapping rules

Mapping rules are used to state correspondences between UNL and NL. They follow the general syntax:

<DEFINIENDUM> = <DEFINIENS>;

Where <DEFINIENDUM> is an element of UNL and <DEFINIENS> is an element of NL, or vice-versa.

Examples of mapping rules

• From UNL to NL
  • @pl = PLR;
  • @past = PAS;
  • @passive = PSV;
  • @male = MCL;
  • @past,@progressive = PAS,PGS;
• From NL to UNL
  • PLR = @pl;
  • PAS = @past
  • MCL = @male
  • PAS,PGS = @past.@progressive

Replacement rules

Replacement rules are used to state correspondences inside UNL or NL. They follow the general syntax:

<DEFINIENDUM> = <DEFINIENS>;

Where <DEFINIENDUM> and <DEFINIENS> are both elements of UNL, or are both elements of NL. Replacement rules are mainly used to avoid redundancy and unnecessary proliferation of rules.

Examples of replacement rules

• Inside UNL
  • @dual = @pl; (replace the attribute @dual by the attribute @pl)
• Inside NL
  • DUA = PLR; (replace the attribute DUA by the attribute PLR)