DEF y=x^2
DEF B=A+2
DEF s=2*t+3
SET WINDOW -5.5,5.5,-0.5,10.5
DRAW axes
FOR x=-5.2 TO 5.2 STEP 0.001
   PLOT LINES: x,y
NEXT x
FOR A=-1 TO 2 STEP 0.001
   PLOT LINES: A,B
NEXT A
FOR t=-1 TO 3 STEP 0.001
   PLOT LINES: t,s
NEXT t
DRAW DISK WITH SCALE(0.1)*SHIFT(-1,1)
DRAW DISK WITH SCALE(0.1)*SHIFT(2,4)
DRAW DISK WITH SCALE(0.1)*SHIFT(3,9)
END