On weakly arithmetic progressions
β Scribed by Egbert Harzheim
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 230 KB
- Volume
- 138
- Category
- Article
- ISSN
- 0012-365X
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β¦ Synopsis
A set of real numbers a~ < a 2 <... < cl L is called a weakly arithmetic progression of length L, if there exist L consecutive intervals I i = [x i\_ ~, xl), i = 1 ..... L, of equal length with a~El i. Here we consider conditions from which the existence of weakly arithmetic progressions can (resp. cannot) be deduced of a given length.
In the following JV (resp. W'o) denotes the set of positive (resp. nonnegative) integers.
Generalizing the notion of arithmetic progression the following was defined in [1]. Definition. Let L~JV'. A set of real numbers aa <..-< aL is called a weakly arithmetic' progression of length L (shortly a WAPL) if there exist real numbers Xo < '.-(L--1) FKq (case 1) or [AI>FLK-k-].(L-1) k (case 2) holds, then A contains a WAPL.
Proof. We assume that A has no WAPL and that case 1 holds. Then we subdivide [0, L r) into L consecutive subintervals (left-closed, right-open) of equal length L r-1
π SIMILAR VOLUMES
Let Se be a countably family of in&rite subsets of nonnegative integers. Using a diagonal argumpnt it is straight forward to select for each XE& an infinite subset S(X) r~ X such that the family (S(X) 1 XE Se) is disjoint. Also, there exists a mapping A :N --, N such that for every XE & and i EN the
~roughout this paper we use the following notatians: The cardinality of the finite set Y is denoted by ISI -.s& B8, . I s den&e finite or infinite sets of positive integers. If & is a finite or infinite set of positive integers, then S(d) denotes the set of the distinct positive integers n that can