A nonstandard approach to arithmetic.
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JOSÉ F. PRIDA (1999)
Revista de la Real Academia de Ciencias Exactas Físicas y Naturales
Vítězslav Švejdar (1978)
Commentationes Mathematicae Universitatis Carolinae
Matthias Ragaz (1983)
Archiv für mathematische Logik und Grundlagenforschung
Matthias Ragaz (1983)
Archiv für mathematische Logik und Grundlagenforschung
Crvenković, S., Delić, D. (1996)
Novi Sad Journal of Mathematics
Laurent Moret-Bailly, Alexandra Shlapentokh (2009)
Annales de l’institut Fourier
Let be a one-variable function field over a field of constants of characteristic 0. Let be a holomorphy subring of , not equal to . We prove the following undecidability results for : if is recursive, then Hilbert’s Tenth Problem is undecidable in . In general, there exist such that there is no algorithm to tell whether a polynomial equation with coefficients in has solutions in .
A. Nabutovsky (1996)
Geometric and functional analysis
Yuri Gurevich (1982)
Archiv für mathematische Logik und Grundlagenforschung
Vinokurov, N.S. (2006)
Sibirskie Ehlektronnye Matematicheskie Izvestiya [electronic only]
Olivier Finkel (2009)
RAIRO - Theoretical Informatics and Applications
We show that many classical decision problems about 1-counter ω-languages, context free ω-languages, or infinitary rational relations, are Π½ -complete, hence located at the second level of the analytical hierarchy, and “highly undecidable”. In particular, the universality problem, the inclusion problem, the equivalence problem, the determinizability problem, the complementability problem, and the unambiguity problem are all Π½ -complete for context-free ω-languages or for infinitary rational...
L. Szczerba, Alfred Tarski (1979)
Fundamenta Mathematicae
Kurt Hauschild (1982)
Commentationes Mathematicae Universitatis Carolinae
Popov, V.Yu. (2000)
Siberian Mathematical Journal
Petr Hájek (1987)
Commentationes Mathematicae Universitatis Carolinae
Ursu, V.I. (2000)
Siberian Mathematical Journal
V.H. Dyson, J.P. Jones (1982)
Archiv für mathematische Logik und Grundlagenforschung
Hans Kleine Büning (1981)
Archiv für mathematische Logik und Grundlagenforschung
Pinus, A.G. (2007)
Sibirskij Matematicheskij Zhurnal
Dana May Latch (1991)
Cahiers de Topologie et Géométrie Différentielle Catégoriques
Dietrich Kuske (2006)
RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications
It is shown that small fragments of the first-order theory of the subword order, the (partial) lexicographic path ordering on words, the homomorphism preorder, and the infix order are undecidable. This is in contrast to the decidability of the monadic second-order theory of the prefix order [M.O. Rabin, Trans. Amer. Math. Soc., 1969] and of the theory of the total lexicographic path ordering [P. Narendran and M. Rusinowitch, Lect. Notes Artificial Intelligence, 2000] and, in case of the subword...
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