Errors in demo (PR#10527)

I have no idea what 'demo' this is.  When I open R it says

   Type 'demo()' for some demos, 'help()' for on-line help, or
   'help.start()' for an HTML browser interface to help.

and this is none of those.  At a guess you meant

x <- 1:20
w <- 1 + sqrt(x)/2
dummy <- data.frame(x=x, y= x + rnorm(x)*w)
dummy
fm <- lm(y ~ x, data=dummy)

from the 'sample session' in 'An Introduction to R'.  In which case, this 
is your own typing error (- for ~, and we do put spaces in to make it 
easier to read).

Please do read the R FAQ *before* 'blowing off' a false report.