We establish that for every computably enumerable (c.e.) Turing degree b, the upper cone of c.e. Turing degrees determined by b is the degree spectrum of the successor relation of some computable linear ordering. This follows from our main result, that for a large class of linear orderings, the degree spectrum of the successor relation is closed upward in the c.e. Turing degrees.

Let A be a uniformly complete almost f -algebra and a natural number p ∈ {3, 4, . . . }. Then Πp(A) = {a1 . . . ap; ak ∈ A, k = 1, . . . , p} is a uniformly complete semiprime f -algebra under the ordering and multiplication inherited from A with Σp(A) = {a; 0 ≤ a ∈ A} as positive cone.

Quantum field theories based on interactions which contain the Moyal star product suffer, in the general case when time does not commute with space, from several diseases: quantum equation of motions contain unusual terms, conserved currents can not be defined and the residual spacetime symmetry is not maintained. All these problems have the same origin: time ordering does not commute with taki...

Bogdan and Kolumbán [3] gave sufficient conditions for closedness of the solution map defined on the set of parameters. They considered the parametric equilibrium problems governed by topological pseudomonotone maps depending on a parameter. In this paper we generalize this result for parametric vector equilibrium problems with trifunctions. Let X and Y be Hausdorff topological spaces and P , t...

resorption of tooth structures can occur as a result of physiological, pathological, and idiopathic factors. early diagnosis and appropriate treatment can prevent its serious complications. this case report presents surgical endodontic management of a trauma-induced perforating external root resorption, which was diagnosed with the help of cone beam computed tomography. following root canal tre...

We describe a simple scheme for constructing finitely generated monoids in which left-divisibility is a linear ordering and for practically investigating these monoids. The approach is based on subword reversing, a general method of combinatorial group theory, and connected with Garside theory, here in a non-Noetherian context. As an application we describe several families of ordered groups wh...

Let E be a real Banach space of operators ordered by a cone K. We give a sufficient condition for that each chain which is bounded above has a supremum. This condition is satisfied in several classical cases, as for the Loewner ordering on the space of all symmetric operators on a Hilbert space, for example. MSC classification (2010): 46B40, 47L07