Characteristic functions and products of derivatives
type: Item
instance of: scholarly article
title: Characteristic functions and products of derivatives
zbMATH Open document ID: 0732.26007
author: Jan Mařík
published in: Real Analysis Exchange
publication date: 1991-01-01T00:00:00Z
review text: The following Theorem is proven: For a subset S of the reals R the following are mutually equivalent: (1) the characteristic function of S is a product of finitely many derivatives; (2) S is ambiguous and \(T=R\setminus S\) is porous; (3) there exist derivatives f and g such that \(f=g=1\) on S and \(fg=0\) on T.
Mathematics Subject Classification ID: 26A24
Mathematics Subject Classification ID: 26A21
zbMATH DE Number: 4210453
zbMATH Keywords: ambiguous set
zbMATH Keywords: porous set
zbMATH Keywords: characteristic function
zbMATH Keywords: product of finitely many derivatives
MaRDI profile type: Publication
description: scientific article; zbMATH DE number 4210453