Notes on Approximations in Hyperrings
Xueling Ma, Jianming Zhan and Bijan Davvaz
In this note, we show by examples that Propositions 3.1(i), (ii) and 3.16(ii) in [B. Davvaz, Approximations in hyperrings, J. Mult-Valued Logic & Soft Comput. 15(2009) 471-488] are not correct and offer their modified versions.
Keywords: Hyperring; lower(upper) approximation space; normal hyperideal.
2010 Mathematics Subject Classification: 16Y99; 20N20.