PROCeuler("-0.07*(y-20)", 100, 0, 100, 2)
      PROCeuler("-0.07*(y-20)", 100, 0, 100, 5)
      PROCeuler("-0.07*(y-20)", 100, 0, 100, 10)
      END

      DEF PROCeuler(df$, y, a, b, s)
      LOCAL t, @%
      @% = &2030A
      t = a
      WHILE t <= b
        PRINT t, y
        y += s * EVAL(df$)
        t += s
      ENDWHILE
      ENDPROC