Need help with VXML again (fun deps and forall types)

Some time I've announced that I'm working on VXML, a validating xml
library.

The use case which makes trouble is elem+ (one or more)

<!ELEMENT root (a|b|(c,d+))*>

This example is encoded in this way:

root -> St 1

 id :1
   endable : True
   a -> St 1
   b -> St 1
   c -> St 12

 id :11
   endable : True
   (a|b|c) -> St 1
   d -> St 11

 id :12
   endable : False
   d -> St 11

to be read as:
When creating a new root element start with state 1, then expect one of
a,b,c subelemnts.