Classically, any absolute continuous real function is of bounded variation and hence can always be expressed as a difference of two increasing continuous functions (socalled Jordan decomposition). The effective version of this result is not true. In this paper we give a sufficient and necessary condition for computable real functions which can be expressed as two computable increasing functions...

Using ideas and results from recursion theory and effective descriptive set theory we provide a partial answer to the Decomposabilty Conjecture in Polish spaces of small inductive dimension. The latter extends earlier work of Motto Ros and Pawlikowski-Sabok. We also state a conjecture, which would allow our arguments to be carried out in all Polish spaces, and we give the analogous results in t...

We prove that each elementary theory has a unique decomposition into indecomposable components and formulate a decomposability criterion. Definition 1 A theory T of signature Σ is called decomposable, if T is the deductive closure in the predicate calculus of signature Σ of all sentences of some theories S1 and S2 with the disjoint signatures Σ1 and Σ2, Σ1∪Σ2 = Σ (we use the notation: T = S1 ] ...

Let RsM denote the Singer construction on an unstable module M over the Steenrod algebra A at the prime two; RsM is canonically a subobject of Ps⊗M , where Ps = F2[x1, . . . , xs] with generators of degree one. Passage to A -indecomposables gives the natural transformation RsM → F2⊗A (Ps⊗M), which identifies with the dual of the composition of the Singer transfer and the Lannes-Zarati homomorph...

In French, regardless of stem regularity, inflectional verbal suffixes are extremely regular and paradigmatic. Considering the complexity of the French verbal system, we argue that all French verbs are polymorphemic forms that are decomposed during visual recognition independently of their stem regularity. We conducted a behavioral experiment in which we manipulated the surface and cumulative f...

It is well-known that all orthogonal arrays of the form OA(N, t+1, 2, t) are decomposable into λ orthogonal arrays of strength t and index 1. While the same is not generally true when s = 3, we will show that all simple orthogonal arrays of the form OA(N, t + 1, 3, t) are also decomposable into orthogonal arrays of strength t and index 1.

Abelian groups are classified by the existence of certain additive decompositions of group-valued functions of several variables.

The object of the present paper is to study weakly projective symmetric manifolds and its decomposability with several non-trivial examples. Among others it is shown that in a decomposable weakly projective symmetric manifold both the decompositions are weakly Ricci symmetric.

A partial characterization (a necessary condition for decomposability and a criterion for nondecomposability) of decomposable positive maps is given. Furthermore, a clarification of the structure of the set of positive maps is provided. W.A.M. was partially supported by SCALA (IST-2004-015714) M.M.was partially supported by KBN grant PB/1490/PO3/2003/25 1 2