We prove the decidability for a class of languages which extend BST and NP-completeness subclass them. The extended with unordered cartesian product, ordered product powerset fall in this last subclass.

In this paper, we will present a deenability theorem for rst order logic. This theorem is very easy to state, and its proof only uses elementary tools. To explain the theorem, let us rst observe that if M is a model of a theory T in a language L, then, clearly, any deenable subset S M (i.e., a subset S = fa j M j = '(a)g deened by some formula ') is invariant under all automorphisms of M. The s...

This is Part 6 of a tutorial series on Term Vector Theory. The Extended Boolean Model is discussed. By varying the model p-norm parameter, from p = 1 to p = , we can vary its ranking behavior from that of a vector spacelike to that of a strict Boolean-like.

In this paper we define, inspired by ring theory, the class of maximal residuated lattices with lifting Boolean center and prove a structure theorem for them: any maximal residuated lattice with lifting Boolean center is isomorphic to a finite direct product of local residuated lattices. MSC: 06F35, 03G10.

Bent functions (Dillon 1974; Rothaus 1976) are extremal objects in combinatorics and Boolean function theory. They have been studied for about 40 years; even more, under the name of difference sets in elementary Abelian 2-groups. The motivation for the study of these particular difference sets is mainly cryptographic (but bent functions play also a role in coding theory and sequences; and as di...

Bent functions (Boolean functions with extreme nonlinearity properties) are actively studied for their numerous applications in cryptography, coding theory, and other fields. New statements of problems lead to a large number of generalizations of the bent functions many of which remain little known to the experts in Boolean functions. In this article, we offer a systematic survey of them.