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Abstract

<jats:p>Closed classes under superposition are examined in π‘˜-valued logic. E. Post established that the lattice (on inclusion) of all closed classes in two-valued logic is countable. Besides, each closed class has a finite basis in two-valued logic. Yu. I. Yanov and A. A. Muchnick proved that the lattice of all closed classes in π‘˜-valued logic is continuous at each π‘˜ &gt; 3. Besides, there are closed classes without a basis and closes classes of a countable basis in π‘˜-valued logic at π‘˜ &gt; 3. Because of the continuity on the lattice of all closed classes at π‘˜ &gt; 3, its sub-lattices are examined. In particular, the closed class of all functions, that are represented by polynomials modulo π‘˜, is considered in π‘˜-valued logic. This closed class contains all functions of π‘˜-valued logic, if and only if π‘˜ is a prime number. If π‘˜ is a composite number, then this closed class is not even pre-complete. In works of A. N. Cherepov, A. B. Remizov, A. A. Krokhin, K. L. Safin, E. V. Sukhanov, D. G. Meschaninov and of others the structure of sub-lattices and of over-lattices is examined for the closed class of all polynomial functions at composites π‘˜. In this work at each composite number π‘˜ the continuity of the sub-lattice is established for the closed class of all polynomial functions in π‘˜-valued logic.</jats:p>

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Keywords

closed logic π‘˜ classes π‘˜valued

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