Sums and products of intervals in ordered groups and fields
Tamás Glavosits, Zsolt Karácsony · Acta Universitatis Sapientiae Mathematica · 2021
Abstract We show that the sum of two intervals in an ordered dense Abelian group is also an interval such that the endpoints of the sum are equal to the sums of the endpoints. We prove analogous statements concerning to the product of two intervals.