FIELD: hierarchical structure of libraries. SUBSTANCE: each library provides interface for access to corresponding data structure such as data structure of character encoding table or syntactic tree. Libraries are structured in multiple levels of abstract constructions which include concrete representation, level of representation, level of definitions and conceptual level. Interface to library for example consists of conceptual level and part of level of definitions. Concrete representation and level of representations are hidden from software engineer. In addition invention provides interface means for each level of operations for creation, removal, reversal, update or output. EFFECT: increased functional capabilities. 12 cl, 4 dwg
