Showing papers on "Chomsky hierarchy published in 1999"
01 Jan 1999
TL;DR: This review paper will report on some recent discoveries in the area of Formal Languages, chiefly by F. Otto, G. Buntrock and G. Niemann, and find that the deterministic growing context-sensitive languages turn out to be identical to an interesting family of formal languages definable in a certain way by confluent reduction systems.
Abstract: This review paper will report on some recent discoveries in the area of Formal Languages, chiefly by F. Otto, G. Buntrock and G. Niemann. These discoveries have pointed out certain break-throughs connected with the concept of growing context-sensitive languages, which originated in the 1980’s with a paper by E. Dahlhaus and M.K. Warmuth. One important result is that the deterministic growing context-sensitive languages turn out to be identical to an interesting family of formal languages definable in a certain way by confluent reduction systems.
17 citations
TL;DR: Families of languages generated by (not only extended) conditional tabled eco-grammar systems are studied and the known results about classes of ECTEG languages are summarized in a hierarchy diagram.
Abstract: Families of languages generated by (not only extended) conditional tabled eco-grammar systems are studied. Characterization of some important classes of formal languages via eco-grammar systems is given. The known results about classes of ECTEG languages are summarized in a hierarchy diagram.
3 citations
TL;DR: It is proven that several hierarchies of these language classes collapse and that the ECTEG1(1,2;s) class characterizes context-sensitive languages.
Abstract: As it was shown in related papers, a conditional tabled eco-grammar system represents itself a rich multi-agent formal framework, allowing among other things to characterize some important classes of formal languages. Some new results about generative power of extended conditional tabled eco-grammar (ECTEG) systems are shown. In order to extend the previous research the main interest is devoted to so far less studied systems with scattered mode context conditions. It is proven that several hierarchies of these language classes collapse and that the ECTEG1(1,2;s) class characterizes context-sensitive languages.
2 citations
01 Apr 1999
TL;DR: Investigations into differences between expert and novice problem-solving techniques falls within the area of cognitive science.
Abstract: Investigations into differences between expert and novice problem-solving techniques falls within the area of cognitive science. Cognitive science refers to the interdisciplinary study of the acquisition and use of knowledge [1]. The field includes as contributing disciplines: artificial intelligence, cognitive psychology, linguistics, philosophy of mind and language, anthropology, neuroscience, and education. The cognitive science movement is very diverse, containing within it several viewpoints.
1 citations
TL;DR: The paper introduces the concept of cut-and-paste polynomial function, which models operations on words inspired from contextual languages and DNA computing, and shows how fixed-point equations attached to such functions become generative devices for new classes of languages.
Abstract: The paper introduces the concept of cut-and-paste polynomial function, which models operations on words inspired from contextual languages and DNA computing. Fixed-point equations attached to such functions become generative devices for new classes of languages. The class of first-degree 2CP-languages is shown to be incomparable with the Chomsky hierarchy. We give some examples which motivate further study of higher degree CP-languages.
1 citations