The undecidability of form equivalence for context-free and E0L forms

Valtteri Niemi
1984 Theoretical Computer Science  
This paper studies the decidability status of various equivalence problems in form theory. Most of our discussions concern the notion of a language form. We compare the form equivalence problem be!wcen language forms with the ordinary equivaienc'e problem between languages. However, the main results deal with L forms and grammar forms under strict intcrpretations. We prove that the form equivalence problem is undecidable for (a) context-free grammar forms, and (b) EOL forms. The proofs of these
more » ... results are based on our investigations concerning language forms.
doi:10.1016/0304-3975(84)90045-8 fatcat:dxldpzae6fcpfmuxtdbo42ty2e