Some algebras of recursively enumerable sets and their applications to the fuzzy logic

Algebras of operations defined on recursive enumerable sets of different kinds are considered. Every such algebra is given by the list of operations taking part in it; besides, in every considered algebra some list of basic elements is fixed. An element of algebra is said to be inductively representable in this algebra if it can be obtained from the basic elements by use of operations contained in the algebra. Two kinds of recursively enumerable sets are considered: recursively enumerable sets in the usual sense and fuzzy recursively enumerable sets. Some algebras of operations are introduced on two-dimensional recursively enumerable sets of the mentioned kinds. An algebra $\theta$ is constructed, where all two-dimensional recursively enumerable sets are inductively representable. A subalgebra $\theta^0$ of the algebra $\theta$ is constructed, where all two-dimensional recursively enumerable sets described by formulas of M. Presburger's arithmetical system (and only such sets) are inductively representable. An algebra $\Omega$ is constructed where all two-dimensional recursively enumerable fuzzy sets are inductively representable. A subalgebra $\Omega^0$ of the algebra $\Omega$ is constructed such that fuzzy recursively enumerable sets inductively representable in it can be considered as fuzzy analogues of sets described by the formulas of M. Presburger's arithmetical system.