2021/07/15 by Burai, Pál, Kiss, Gergely, Szokol, Patricia
#26B99 #26E60 #39B05 #39B22 #Classical Analysis and ODEs (math.CA) #FOS: Mathematics
paper · doi:10.48550/arxiv.2107.07391
In this paper we show that bisymmetry, which is an algebraic property, has a regularity improving feature. More precisely, we prove that every bisymmetric, partially strictly monotonic, reflexive and symmetric function F:I2→ I is continuous. As a consequence, we obtain a finer characterization of quasi-arithmetic means than the classical results of Aczél, Kolmogoroff, Nagumo and de Finetti.