[R] ploting several functions on the same plot

[Julio Sergio]

I want to superimpose two functions plots in the same page. The functions L0 
and L1, defined below


  f0 <- function(mu, xm, ds, n) {
    1 - pnorm((xm-mu)/(ds/sqrt(n)))
  }

  f1 <- function(mu,n) f0(mu, 386.8, 48, n)

  L0 <- function(mu) f1(mu, 36)

  plot(L0,ylim=c(0,1),xlim=c(360,420))

  L1 <- function(mu) f1(mu,100)
  lines(L1)

The plot of L0 works pretty well. However, when trying to plot the second 
function, L1, the interpreter issues an error: 

Error in as.double(y) : 
  cannot coerce type 'closure' to vector of type 'double'

How can I solve my problem, since I want to have both plots with the same 
quality? I mean, I don't want to produce an approximating polygonal for the 
second function.

Thanks, 

 -Sergio.