SET WINDOW -0.8,-0.5,1,1.3
FOR k=7 TO 100
   SET COLOR MIX(k) 1,k/100,k/100
NEXT k
FOR i=-0.8 TO -0.5 STEP 0.3/500
   FOR j=1 TO 1.3 STEP 0.3/500
      LET x=0.5
      LET y=0
      WHEN EXCEPTION IN
         FOR k=1 TO 100
            LET a=x-x^2+y^2
            LET b=y-2*x*y
            LET x=a*i-b*j
            LET y=a*j+b*i
         NEXT k
         SET LINE COLOR 1
      USE
         SET LINE COLOR k
      END WHEN
      PLOT LINES:i,j
   NEXT j
NEXT i
END