منابع مشابه
Functions Whose Composition with Baire Class One Functions Are Baire Class One
We study the functions whose composition with Baire class one functions are Baire class one functions. We first prove some characterizations of such functions, then investigate a subclass of such functions which are defined in a natural way.
متن کاملRanks on the Baire Class Ξ Functions
In 1990 Kechris and Louveau developed the theory of three very natural ranks on the Baire class 1 functions. A rank is a function assigning countable ordinals to certain objects, typically measuring their complexity. We extend this theory to the case of Baire class ξ functions, and generalize most of the results from the Baire class 1 case. We also show that their assumption of the compactness ...
متن کاملRecovering Baire One Functions on Ultrametric Spaces
We find a characterization of those Polish ultrametric spaces on which each Baire one function is first return recoverable. The notion of pseudo-convergence originating in the theory of valuation fields plays a crucial role in the characterization.
متن کاملArray Convergence of Functions of the Rst Baire-class
We show that every array (x(i; j) : 1 i < j < 1) of elements in a point-wise compact subset of the Baire-1 functions on a Polish space, whose iterated pointwise limit lim i lim j x(i; j) exists, is converging Ramsey-uniformly. An array (x(i; j) i<j) in a Hausdorr space T is said to converge Ramsey-uniformly to some x in T , if every subsequence of the positive integers has a further subsequence...
متن کاملConnectivity of diagonal products of Baire one functions
We characterize those Baire one functions f for which the diagonal product x 7→ (f(x), g(x)) has a connected graph whenever g is approximately continuous or is a derivative.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Fundamenta Mathematicae
سال: 2003
ISSN: 0016-2736,1730-6329
DOI: 10.4064/fm179-3-3