R help - Dec 2014 - Is there a plotmath symbol \mapsto?

Dear Professor Ripley,

Thank you for your reply.
Do you specify \u21A6 via something like this?

plot(1, main=expression(symbol("\u21A6")))

This gives an the 'registered trademark symbol' (circled R) for me
(also cairo-based Linux).

Thanks and cheers,

Marius