Chapter 1.   Structure of UNL

UNL consists of three types of components: Universal Words (UWs), Relations and Attributes. Each component plays a different role: An UW is the vocabulary of UNL which expresses the concept of a word, while a Relation links two UWs with semantic information, and an attribute expresses information such as tense, aspect and mood with respect to the speaker.

Semantic Information of a Sentence:

1.          The Concept

The most important information of a sentence is the concept that it convey. This concept is represented by combination of UWs and Relations that are to be universal to the utmost, so as the representation is to be independent of language.

2.          Other information

The tense, aspect or mood with respect to the speaker is generally given in different ways by different languages. It is wholly expressed by Attributes in UNL. Information with respect to the speaker includes three subsets:

(1)  Time and Aspects

Information on the tense and aspects. These attributes are designed focusing on the each part of point of an event of state that the sentence expresses.

(2)  Speaker's View of Reference and Communication.

Information related to the concept of a sentence. The attributes for expressing meanings of generality, specificity, negation, emphasis, focus, topic, etc are included. Most of these attributes are designed focusing on each (part of) concept (s) in a sentence.

(3)  Speaker's Attitudes, Feelings and Viewpoints

Information on the Mood.

Attributes are designed from a common perspective, although some of them cover special cases of some languages. In deconversion or enconversion of a native language, such attributes need to be transferred into or from its own expressions respectively. 

Syntactic Information of a Sentence

Information such as cases of a verb should be managed by each language module and should not be represented in the UNL expressions.