Showing papers on "Indexed language published in 1981"
TL;DR: There exist two distinct infinite hierarchies of AFG which exhaust the derivation bounded AFG and are shown to be strongly incomparable to the other; that is, the first member of each generates some language not generated by a fixed but arbitrary member of the other.
Abstract: An abstract family of grammars (AFG) may be defined as a class of grammars for which the corresponding class of languages forms an abstract family of languages (AFL) as defined by Ginsburg and Greibach. The derivation bounded grammars of Ginsburg and Spanier is an example of an AFG which is properly included in the class of all context-free grammars (also AFG). The main result is that there exist two distinct infinite hierarchies of AFG which exhaust the derivation bounded AFG such that the AFL associated with the kth member of one of these AFG hierarchies is properly included in the AFL associated with the k-lst member of that same hierarchy. Each hierarchy is shown to be strongly incomparable to the other; that is, the first member of each generates some language not generated by a fixed but arbitrary member of the other. We designate these hierarchies as the hierarchies of left and right dominant grammars (languages)
3 citations
TL;DR: It is proved that the family of the languages generated by 1-fold fuzzy grammars with context-sensitive rules and grade larger than λ,0≦λ<1, is equal to the familyof the context sensitive languages.
Abstract: It is proved that the family of the languages generated by 1-fold fuzzy grammars with context-sensitive rules and grade larger than λ,0≦λ<1, is equal to the family of the context sensitive languages. Also, one shows that the family of the languages generated by fuzzy grammars with context-sensitive rules and grade larger than λ,0≦λ<1, is included in the family of the context-sensitive languages.
1 citations
24 Aug 1981