meg egy pelda: x=3+2 y=6-1 u=2*2 z=2+2 nyilvanvaloan: {x,u}={y,z} es pont azert, mert "x","y","u","z" szimbolumok. raadasul meg az "1","2","3"," 6","+","=","-","*" is szimbolumok. math (webes bekuldes, a bekuldo gepe: saprx01x.nokia.com)