Interactive ghostscript question: Showing defined procedures

[Joel Hammer]

I find that a good way to write postscript is to us the
interactive facility provided by gs. Start a gs session,
define some fonts so you can output stuff, and then start
writing code. The indispensable command is pstack, which
displays the contents of the stack.

Does anyone know of an analogous command for showing
defined procedures?

Thanks,

Joel