3 LET t=INT PI: LET w=t+t: LET n=t*t: FOR x=-n TO n: FOR y=-n TO n: LET a=ABS x: LET b=ABS y: DEF FN p(z)=ABS (b-a)=z AND b<z+t AND a<z+t: DEF FN s(a,b)=(b=w OR b=w+SGN PI) AND a=w-SGN PI: PRINT AT y+n,x+n+w;"*" AND ((a=b AND a<n-SGN PI) OR a*b=NOT PI OR FN p(t) OR FN p(w) OR FN s(a,b) OR FN s(b,a)): NEXT y: NEXT x
