!Cassini

LET Xmax = 5
LET Ymax = 5
SET WINDOW -Xmax,Xmax,-Ymax,Ymax
SET POINT STYLE 1
DRAW AXES 

LET stp = 0.01
LET e = 0.005

LET c = 1
LET p = 0.98

FOR x=-Xmax TO Xmax STEP stp
   FOR y=-Ymax TO Ymax STEP stp
      LET r1 = SQR((-x-c)*(-x-c) + y*y)
      LET r2 = SQR((x-c)*(x-c) + y*y)
      LET s = r1 * r2
      IF ABS(s - p)<0.005 THEN
         PLOT POINTS :x, y
      END IF
   NEXT y
NEXT x

END