p:output binding error?

in 5:4 it says, "It is a static error (err:XS0029) to specify a binding for
a p:output inside a p:declare-step for an atomic step."

Does that mean it's an error to specify a binding for all output ports or
just for the output port named "result"?  I think it means the former.

James Garriss
http://garriss.blogspot.com