Link indicators and other means of cohesion indication in retrieval languages—syntactic and logico-semantic properties

摘要

Cohesion, i.e. unspecified relationship of text components may be specified by means of link indicators, brackets, (cohesion) separators, and other vehicles. The paper deals with the formal properties, structural consequences, similarities and differences of the first three. The method of analysis is based upon formal (generative) grammars employed to define the syntax of the description (indexing) and query sublanguages and upon correspondence rules used to specify each particular formal relevance mapping. A special algorithmic language is explained (in Appendix B) and used to formulate the correspondence rules with nonterminal symbols of the formal grammars (one for the description sublanguage, the other for the queries) being utilized in the definition of formal relevance. The approach facilitates formulation of new ideas about translatability and retrieval power of retrieval languages.