f(x) := x + (x+1)^-1;
load(draw);
draw2d(terminal=svg,file_name="SlantAsymptoteError",
  color=black,font="Times",
  user_preamble="set termoption enhanced; set mxtics; set mytics;set key at 5.5,7",
  xtics_axis=true,ytics_axis=true,grid=true,yrange=[-1,7],
  xaxis=true,yaxis=true,axis_top=false,axis_bottom=false,axis_left=false,axis_right=false,
  line_width=2,label(["x",7,0.2],["y",0.2,7]),
  color=black,key="f(x) = x + (x+1)^{-1}",explicit( f(x) ,x,-1,7),
  color=red,key="asymptote",explicit(x,x,-1,7),
  color=green,points_joined=true,key="",
  points([1,1],[1,f(1)]),points([2,2],[2,f(2)]),points([3,3],[3,f(3)]),
  points([4,4],[4,f(4)]),points([5,5],[5,f(5)]),key="error",points([6,6],[6,f(6)])
 );