I am experimenting with the Inormation Structure library currently, creating basic grammars which place focus and contrastive focus in various positions in the sentence. The library creates phrase structure rules such as this one:
The problem is the grammar does not load, complaining about an invalid constraint. Turns out the invalid constraint is the ICONS-KEY on the head daughter (meaning, if I remove that constraint, the grammar loads).
I wonder how I should fix it (assuming this is a bug and not an invalid choices file).
Here’s the choices; I did not include any information structure markers, perhaps that is problematic?
section=info-str focus-pos=clause-final topic-first=on c-focus-pos=clause-initial
Assuming these choices are a valid set, how should I proceed?
I am not sure what the problem is, as there is no clash between the type and any of its parents that would be obvious to me. Furthermore, removing the parents and just saying the parent is simply sign does not help. Is this something about the feature geometry, like the ICONS-KEY somehow ends up not appropriate in the type?