Open AccessOn the cardinality of a reduced unique range set
Author(s) -
Bikash Chakraborty
Publication year - 2020
Publication title -
ukraïnsʹkij matematičnij žurnal
Language(s) - English
Resource type - Journals
ISSN - 1027-3190
DOI - 10.37863/umzh.v72i11.594
Subject(s) - meromorphic function , cardinality (data modeling) , set (abstract data type) , range (aeronautics) , mathematics , discrete mathematics , combinatorics , pure mathematics , computer science , programming language , engineering , data mining , aerospace engineering
UDC 517.5Two meromorphic functions are said to share a set ignoring multiplicities (IM) if has the same pre-images under both functions. If any two nonconstant meromorphic functions, sharing a set IM, are identical, then the set is called a “reduced unique range set for meromorphic functions'' (in short, RURSM or URSM-IM).From the existing literature, it is known that there exists a RURSM with seventeen elements. In this article, we reduced the cardinality of an existing RURSM and established that there exists a RURSM with fifteen elements. Our result gives an affirmative answer to the question of L. Z. Yang (Int. Soc. Anal., Appl., and Comput., 7 , 551–564 (2000)).