Abstract. Gábor Czédli and György Pollák proved that if $P$ is a finite quasi ordered set in which no two incomparable elements have a common upper bound, then the coalitions form a quasi lattice. We give a short proof of this result.

AMS Subject Classification (1991): 06B99; 06A99

Keyword(s): Coalition, lattice

Received September 22, 1995, and in revised form October 11, 1995. (Registered under 5669/2009.)