N-rule
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== Type of Normalization Rules == | == Type of Normalization Rules == | ||
| + | Normalization rules are used only to replace strings in the natural language input text. | ||
| + | |||
| + | {|cellpadding="5" border="1" align="center" | ||
| + | |+LL rules | ||
| + | !ACTION | ||
| + | !RULE | ||
| + | !DESCRIPTION | ||
| + | |- | ||
| + | |REPLACE | ||
| + | |(%x):=(%y); | ||
| + | |All the instances of the node %x will be replaced by the node %y | ||
| + | |- | ||
| + | |} | ||
| + | <div align="center">Where %x and %y are nodes.</div> | ||
| + | |||
== Roles of Normalization Rules == | == Roles of Normalization Rules == | ||
Revision as of 16:30, 31 May 2013
Normalization rules are used to prepare the natural language input for automatic processing. They constitute the preprocessing module that applies over the input as a string and runs prior to the tokenization. The set of n-rules forms the Normalization Grammar, or N-Grammar.
Contents |
Syntax
Normalization Rules follow the very general formalism
α:=β;
where the left side α is a condition statement, and the right side β is an action to be performed over α.
Type of Normalization Rules
Normalization rules are used only to replace strings in the natural language input text.
| ACTION | RULE | DESCRIPTION |
|---|---|---|
| REPLACE | (%x):=(%y); | All the instances of the node %x will be replaced by the node %y |
Where %x and %y are nodes.
Roles of Normalization Rules
Normalization roles They have two roles:
- to normalize the input text (to replace abbreviations by their extend forms, to extend contractions, etc.)
- to segment the natural language text into sentences (i.e., to create the tags <SHEAD> (beginning of a sentence), <STAIL> (end of a sentence), <CHEAD> (beginning of a scope) and <CTAIL> (end of a scope) inside the input text). These sentences are used as sentence and clause boundaries, and define the units of processing of the Transformation and Disambiguation grammars.
Examples of Normalization rules
- Segmentation
- ("/.*\./",%x):=(%x)(+STAIL,%y); (creates an STAIL node after any sequence of characters followed by "." (/.*\./);
- ("/\(/",%x):=(+CHEAD,%y)(%x); (creates an CHEAD node before the opening of a parentheses (/\(/);
- Normalization
- ("an "):=("a "); ("an apple" > "a apple")
- ("don't"):=("do not"); ("I don't see" > "I do not see")
