On Fri, 2005-04-01 at 15:38 +0200, Brisa Francesco wrote: > non molto difficile, direi: > > -x*x-x+4+y>0 > x+5/2>0 > 16/10->0 > ((x-0.8)2+(y-1.6)2-0.44) != 0 > > anche: > log(-x*x-x+4-y)!=0 -> -x*x-x+4-y !=1 > log(16/10-x)!=0 -> 16/10-x != 1 > brisa rules ;)