109 urn:lsid:arphahub.com:pub:3dc5f44e-8666-58db-bc76-a455210e8891 JUCS - Journal of Universal Computer Science jucs 0948-695X 0948-6968 Journal of Universal Computer Science 10.3217/jucs-008-07-0722 27898 Research Article F.4.3 - Formal Languages Heyting Algebras and Formal Languages Kuich Werner kuich@tuwien.ac.at 1 Sauer Norbert 2 Urbanek Friedrich 3 Institut für Algebra und Computermathematik, Technische Universität Wien, Wien, Austria Institut für Algebra und Computermathematik, Technische Universität Wien Wien Austria University of Calgary, , Canada University of Calgary Canada Vienna University of Technology, Vienna, Austria Vienna University of Technology Vienna Austria

Corresponding author: Werner Kuich (kuich@tuwien.ac.at).

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2002 28 07 2002 8 7 722 736 7799FCA8-4E8F-50A9-BDFB-415BF77780FE 6996205 Werner Kuich, Norbert Sauer, Friedrich Urbanek This article is freely available under the J.UCS Open Content License.

By introducing a new operation, the exponentiation of formal languages, we can define Heyting algebras of formal languages. It turns out that some well known families of languages are closed under this exponentiation, e. g., the families of regular and of context-sensitive languages.