Legend names

Hi,

I need to use greek symbols in a legend. When I write:

a <- 1
leg.names <- as.expression(substitute(alpha==p,list(p=a)))
legend("bottomright",legend=leg.names,lty=1)

leg.names <- as.expression(substitute(alpha==lambda==p,list(p=a)))

but this does not work.

Similarly, how can I write alpha=0, lambda=1?

Thank you very much for your help.

Joaquim Santos