Rule
From UNL Wiki
(Difference between revisions)
| Line 1: | Line 1: | ||
| − | + | == Basic concepts == | |
| + | ;[[Node]] | ||
| + | :A node is the most elementary unit in the graph. It is the result of the [[tokenization]] process, and corresponds to the notion of "lexical item". At the surface level, a natural language sentence is considered a list of nodes, and a UNL graph a set of relations between nodes. | ||
| + | ;[[Relation]] | ||
| + | :In order to form a natural language sentence or a UNL graph, nodes are inter-related by relations. In the UNL framework, there can be three different types of relations: linear, syntactic or semantic. | ||
| + | ;[[Hyper-Node]] | ||
| + | :A hyper-node is a sub-graph, i.e., a node containing relations between nodes. | ||
| + | ;[[Hyper-Relation]] | ||
| + | :A hyper-relation is a relation between relations. | ||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
Revision as of 20:26, 16 August 2013
Basic concepts
- Node
- A node is the most elementary unit in the graph. It is the result of the tokenization process, and corresponds to the notion of "lexical item". At the surface level, a natural language sentence is considered a list of nodes, and a UNL graph a set of relations between nodes.
- Relation
- In order to form a natural language sentence or a UNL graph, nodes are inter-related by relations. In the UNL framework, there can be three different types of relations: linear, syntactic or semantic.
- Hyper-Node
- A hyper-node is a sub-graph, i.e., a node containing relations between nodes.
- Hyper-Relation
- A hyper-relation is a relation between relations.
Basic symbols
| Symbol | Definition | Example |
|---|---|---|
| ^ | not | ^a = not a |
| { | } | or | {a|b} = a or b |
| % | index for nodes, attributes and values | %x (see below) |
| # | index for sub-NLWs | #01 (see below) |
| = | attribute-value assignment | POS=NOU |
| ! | rule trigger | !PLR |
| & | merge operator | %x&%y |
| ? | dictionary lookup operator | ?[a] |
| “ “ | string | "went" |
| [ ] | natural language entry (headword) | [go] |
| [[ ]] | UW | [[to go(icl>to move)]] |
| ( ) | node | (a) |
| // | regular expression | /a{2,3}/ = aa,aaa |
- The differences between "", [] and [[]]
- Double quotes are always used to represent strings: "a" will match only the string "a"
- Simple square brackets are always used to represent natural language entries (headwords) in the dictionary: [a] will match the node associated to the entry [a] retrieved from the dictionary, no matter its current realization, which may be affected by other rules (the original [a] may have been replaced, for instance, by "b", but will still be indexed to the entry [a])
- Double square brackets are always used to represent UWs: [[a]] will match the node associated to the UW [[a]]
- Predefined values (assigned by default)
- SCOPE - Scope
- SHEAD - Sentence head (the beginning of a sentence)
- STAIL - Sentence tail (the end of a sentence)
- CHEAD - Scope head (the beginning of a scope)
- CTAIL - Scope tail (the end of a scope)
- TEMP - Temporary entry (entry not found in the dictionary)
- DIGIT - Any sequence of digits (i.e.: 0,1,2,3,4,5,6,7,8,9)
