Some decidability problems of sentential formst †
Tero Harju, Martti Penttonen · International Journal of Computer Mathematics · 1979
Various decidability problems of SF-languages, i.e. sets of sentential forms, of Chomsky grammars are studied. Among the problems are the equivalence, ambiguity, equality to a regular set, and regularity of SF-languages, and the SF-ness of regular languages. All of these problems are undecidable for type 0 grammars, and many of them are decidable for minimal linear grammars. Strongest possible undecidability and decidability results are looked for.