Latex expression in legend R

Question

What should I do to make R display correctly in a legend equivalent to this latex expression?

\alpha \leq \beta 

The following commands handle \ alpha and \ beta correctly, but not the \ leq character:

 expression(paste(alpha, " leq ", beta)) expression(paste(alpha, " <= ", beta)) 

Answer 1

Just use

 expression(alpha <= beta) 

For more information

 ?plotmath