\begin{Schunk}
\begin{Sinput}
 plot(seq(-1, 10, length.out = 21), -10:10, axes = FALSE,  type = "n")
 ## Make some phony graph paper
 abline(v = 0, col= gray(.70)) ##get the idea?
 abline(v = seq(1, 10), col = gray(.80), lwd = 0.7)
 abline(h = seq(-10, 10), col = gray(.80), lwd = 0.7)
 abline(a= 2, b = 0.5, col = "red", lwd = 2)
 abline(coef = c(2, 0.5), col = "black", lwd = 2)
 abline(coef = c(7, -0.3), col = "green", lwd = 4, lty = 3)
 abline(coef = c(-3, 1.1), col = "pink", lwd =2, lty = 4)
 abline(coef = c(-14, 0.8), col = "purple", lwd = 4, lty = 5)
\end{Sinput}
\end{Schunk}
