Title: Characterizations of quasitrivial symmetric nondecreasing associative operations,
Abstract: In this paper we are interested in the class of n-ary operations on an
arbitrary chain that are quasitrivial, symmetric, nondecreasing, and
associative. We first provide a description of these operations. We then prove
that associativity can be replaced with bisymmetry in the definition of this
class. Finally we investigate the special situation where the chain is finite.