newbie: where's the slur?

[Michael]

Hi folks:

I'm trying to score some music (for a friend) and the following measure isn't
typesetting the way I want it to do. Can someone suggest what would work?

I've got two chords, the <e c a> and the <d c a>.  I want ties between the
respective c's and the a's, and a slur between the e and the d.  The ties appear
but the slur is missing.

Tnanks,
Eh!


\version "2.10.5"

\new Staff { 
  \time 2/2 <e'( c'~ a~>2 <d') c' a> 
}