The emptiness of intersection problem for languages of k-valued categorial grammars (classical and Lambek) is undecidable
Annie Foret · Electronic Notes in Theoretical Computer Science · 2004
This paper is concerned with usual decidability questions on grammars for some classes of categorial grammars that arise in the field of learning categorial grammars. We prove that the emptiness of intersection of two langages is an undecidable problem for the following classes: k-valued classical categorial grammars, and k-valued Lambek categorial grammars, for each positive k.