clarification on query

[Carl Pollard]

Hi again Andrew,

I thought I understood your original question but now I am not sure.
Of the options you offer in your clarification, I'd say:

Option one:
	-X  *replace* Y and Z (as in  TG); meaning that the representation
		contains only Y and Z; X is a historial artifact (or vice
		versa, the representation contains only X, and Y and Z are
		historical artifacts.

   No, this is definitely inappropriate for HPSG.


Option two:
	- or does X *contain* Y and Z (as in MP), there is one object in
		the representation (X), which contains all the material
		formerly in Y and Z. Y and Z no long exist except
		derivationally

   I don't understand what this means -- what does it mean to say X contains
   Y and Z, but that Y and Z only exist derivationally?

Option three:
	- or does it *represent* Y and Z (as in GB), X, Y and Z are all
		identifiable objects in the representation (and
		derivation). They are related through structural relations.

   Yes, that seems to me like something that HPSG and GB have in common.


A fourth option (my preference) is to think of the derivations
themselves (or more precisely, proof-theoretic equivalence classes of
them) as objects in their own right, and then think of the grammar as
a higher-order logical theory that talks about these objects. This is
quite different from HPSG or GB.

Cheers,

Carl