D-rule
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| − | '''D-rules''' or | + | '''D-rules''' or 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-rule]]s, they do not provoke transformations, but induce or block them, by assigning priorities to natural language phenomena. The set of d-rules form the '''Disambiguation grammar''', or '''D-Grammar'''. |
== Syntax == | == Syntax == | ||
Revision as of 13:49, 16 August 2013
D-rules or 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. The set of d-rules form the Disambiguation grammar, or D-Grammar.
Contents |
Syntax
D-rules follow the general syntax (UNL Grammar Specs):
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
Types of Disambiguation Rules
There are three types of disambiguation rules:
- Network disambiguation rules
- Tree disambiguation rules
- List disambiguation rules
Network Disambiguation Rules
Network disambiguation rules apply over the network structure of UNL graphs to constrain the application of Tree-to-Network (TN) and Network-to-Network (NN) Transformation Rules. They have the following format:
SEM(A;B)=P;
Where SEM is a semantic relation, A and B are nodes, and P is an integer (from 0 to 255).
Examples
- 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).
Use
| INPUT | TRANSFORMATION RULES | DISAMBIGUATION RULES | OUTPUT |
|---|---|---|---|
| SYN(A,B,C;D,E,F) | SYN(A;D)=agt(;); (higher priority) SYN(A;E)=aoj(;); (lower priority) |
agt(A;F)=0; | aoj(A,B,C;D,E,F) |
Tree Disambiguation Rules
Tree disambiguation rules apply over the intermediate tree structure to constrain the application of List-to-Tree (LT), Network-to-Tree (NT) and Tree-to-Tree (TT) Transformation Rules. They have the following format:
SYN(A;B)=P;
Where SYN is a syntactic relation, A and B are nodes, and P is an integer (from 0 to 255).
Examples
- 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).
Use
| INPUT | TRANSFORMATION RULES | DISAMBIGUATION RULES | OUTPUT |
|---|---|---|---|
| (A,B,C)(D,E,F) | (A)(D)=X(A;D); (higher priority) (A)(E)=X(E;A); (lower priority) |
X(F;A)=255; | X(D,E,F;A,B,C) |
| agt(A,B,C;D,E,F) | agt(A;D)=X(A;D); (higher priority) agt(A;E)=Y(A;E); (lower priority) |
X(B;F)=0; | Y(A,B,C;D,E,F) |
List Disambiguation Rules
List disambiguation rules apply over the natural language list structure to constrain the application of both Tree-to-List (TL) and List-to-List (LL) Transformation Rules. They are also used for word selection. They have the following format:
(A)(B)=P;
Where A and B are nodes, and P is an integer (from 0 to 255).
Examples
- (ART)(BLK)(VER)=0;
- An article (ART) may not precede a verb (VER).
- (ART)(BLK)(NOU)=255;
- Articles (ART) always precede nouns (NOU).
Use
| INPUT | TRANSFORMATION RULES | DISAMBIGUATION RULES | OUTPUT |
|---|---|---|---|
| X(A,B,C;D,E,F) | X(A;D)=(A)(D); (higher priority) X(A;F)=(F)(A); (lower priority) |
(B)(E)=0; | (D,E,F)(A,B,C) |
| INPUT | DICTIONARY | DISAMBIGUATION RULES | OUTPUT |
|---|---|---|---|
| the book | [book] "22222" (POS=VER); (higher priority) [book] "11111" (POS=NOU); (lower priority) |
(ART)(BLK)(VER)=0; | [book] "1111" (POS=NOU); |
Formal Syntax of Disambiguation Rules
Disambiguation rules must comply with the following syntax
<DISAMBIGUATION RULE> ::= <NN RULE> | <TT RULE> | <LL RULE>
<NN RULE> ::= (<SEM>)+ "=" [0-255]";"
<TT RULE> ::= (<SYN>)+ "=" [0-255]";"
<LL RULE> ::= "(" <NODE> ")" ( "(" <NODE> ")" )+ "=" [0-255]";"
<SEM> ::= <TEXT> "(" <NODE> ";" <NODE> ")"
<SYN> ::= <TEXT> "(" <NODE> ";" <NODE> ")"
<NODE> ::= ( (<DESCRIPTION>)( "," <DESCRIPTION> )* )?
<DESCRIPTION> ::= <STRING> | <ENTRY> | <FEATURE> | <RELATION>
<STRING> ::= """<text>"""
<ENTRY> ::= "["<entry>"]"
<FEATURE> ::= <VALUE> | <ATTRIBUTE> | <ATTRIBUTE>"="<VALUE>
<RELATION> ::= <SEM>|<SYN>
<VALUE> ::= <TEXT>
<ATTRIBUTE> ::= <TEXT>
<TEXT> ::= any sequence of characters except whitespace | <REGULAR EXPRESSION>
<REGULAR EXPRESSION> ::= "/"<PERL COMPATIBLE REGULAR EXPRESSIONS>"/"
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))
