Slur from non-existent note

[Garrett Fitzgerald]

Hi, all. I'm transcribing Riley's "In C" to experiment with in my
community band from the CC-licensed version on the IMSLP. The sixth
theme shows two whole notes, slurred to and from empty space between
them. It's pretty well exactly expressed by the LP syntax

C1( S) S( C)

However, when I try this, I get the C-S rendered as I expect, but the
S-C collapses into a slur over the C. Assuming this isn't a bug, how
can I get it to render so the second half of the measure is a mirror
image of the first half? Thanks.

http://imslp.org/wiki/In_C_(Riley,_Terry)