Using [removed]paste( to insert math notation into a legend

Question

I wish to substitute the following (yes, I\'ve written it here in TeX format, just to be clear)
$P_{M1}(\\tilde{z}>z) - P_{M0}(\\tilde{z}>z)$
for

Answer 1

Here is a simple example of how to use values and labels to get what I think you want.

Note that values map the values in the data to the colours you wish to use, while labels are the labels you want displayed (so this is where you would put the expression).

ggplot(data = data.frame(x= c(0,5)),aes(x=x)) +
    stat_function(fun=dnorm,aes(colour = 'red')) + 
    stat_function(fun = dexp, aes(colour = 'blue')) + 
    scale_colour_manual(values = c('red' = 'red','blue' = 'blue'),name = '', 
          labels = expression(P[M1](tilde(z)>0),P[M0](tilde(z)>0)))