Does each narrative structure support a fixed set of querries?

Suppose you have a reader with nars like X_/A or X->Y. After a read operation you ought to be able to query the reader in forms that correspond to the nature of those nars. Some examples:
if X->Y is in the reader you should be able to ask: where, when, how? For X_/A you should be able to ask about intensity or some such. 

Update: Since a NAR has four sub-nars (thing, action, relation, and value) you should be able to say:
nar.Thing(), nar.Action(), nar.Rleation(), or nar.Value(). Each of these is a query that should return VARs that fill the identified slot. This gets confusing for nars with ORDER>1. Working on it...
Update June 2: Got it working nicely via a concept called "lastConst".