\begin{Schunk}
\begin{Sinput}
> plot(x = c(-5, 5), y = c(-10, 20), 
      type = "n", xlab = "", ylab = "")
> points(x = c(-2, 1, 3), y = c(9, 7, 2))
\end{Sinput}
\end{Schunk}
