Lexica

The UNL framework contains three different types of lexical databases: UNL-only, NL-only and UNL-NL.

UNL

The UNL lexical databases are the following:

• The UNL Dictionary, or simply UNL^dic, is a flat list of UW's along with their semantic features
• The UNL Knowledge Base, or simply UNL^kb, is a network with systematic relations between UW's
• The UNL Example Base, or simply UNL^eb, is a network with any relations between UW's

These three databases are nested. The UNL^dic contains UW's and their basic semantic features (such as the information that the UW corresponding to "table" is a nominal concrete concept that belongs to the class of artifacts). The UNL^kb contains the UNL^dic and the set of relations that are necessary to define a UW (such as the information that "table" is a piece of furniture with vertical legs and a flat horizontal surface). The UNL^eb contains the UNL^kb and the set of relations that are often found between UW's (such as the information that tables are normally round or square, that are made of hard materials, etc.).

NL

• The NL Dictionary, or simply NL^dic, is a list of natural language entries with the corresponding morphological and syntactic features.

UNL-NL

• The UNL-NL Dictionary, or simply UNL-NL^dic, is list of systematic lexical mappings between UW's and natural language entries
• The UNLization Memory, or UNL Memory Base, or simply UNL^MB, is a list of mappings between UNL and a given natural language