id: 00894190 dt: j an: 00894190 au: Crown, G.D.; Janowitz, M.-F.; Powers, R.C. ti: Further results on neutral consensus functions. so: Math. Inf. Sci. Hum. 132, 5-11 (1995). py: 1995 pu: la: EN cc: ut: set theoretic approach; consensus function; brick; lattice filter; ultrafilter ci: li: numdam:MSH_1995__132__5_0 ab: Summary: We use a set theoretic approach to consensus by viewing an object as a set of smaller pieces called “bricks”. A consensus function is neutral if there exists a family ${\cal D}$ of sets such that a brick $s$ is in the output of a profile if and only if the set of positions with objects that contain $s$ belongs to ${\cal D}$. We give sufficient set theoretic conditions for ${\cal D}$ to be a lattice filter and, in the case of a finite lattice, these conditions turn out to be necessary. Our final result, which involves a finite distributive join semilattice, provides necessary and sufficient conditions for ${\cal D}$ to be an ultrafilter. rv: