Algebra in the superextensions of semilattices

Taras Banakh, Volodymyr Gavrylkiv

Given a semilattice $X$ we study the algebraic properties of the semigroup $\upsilon (X)$ of upfamilies on $X$. The semigroup $\upsilon (X)$ contains the Stone-Cech extension $\beta (X)$,…