Question 833546
{{{y}}}{{{""=""}}}{{{system(matrix(3,3,

1, if, x<0,
2, if, 0<=x<1,
3, if, x>=1))}}} 

{{{drawing(400,350,-4,4,-2,5,
graph(400,350,-4,4,-2,5),
line(-10,1,-.1,1), line(0,2,.9,2), line(1,3,10,3),
circle(0,1,.15), circle(1,2,.15),
circle(0,2,0.15),circle(0,2,0.13),circle(0,2,0.11),circle(0,2,0.09),circle(0,2,0.07),circle(0,2,0.05),circle(0,2,0.03),circle(0,2,0.01),
circle(1,3,0.15),circle(1,3,0.13),circle(1,3,0.11),circle(1,3,0.09),circle(1,3,0.07),circle(1,3,0.05),circle(1,3,0.03),circle(1,3,0.01)


 )}}}   

Edwin</pre>