Exactly six trade representatives negotiate a treaty : Klosnik , Londi , Manley , Neri , Osata , Poirier .
There are exactly six chairs evenly spaced around a circular table .
Each chair is occupied by exactly one of the representatives .
A small software firm has four offices , numbered 1 , 2 , 3 , and 4 .
Each of its offices has exactly one computer and exactly one printer .
Each of these eight machines was bought in either 1987 , 1988 , or 1989 .
