Regarding the floating quantifiers' theory on external argument's movement.
These data raises two different problems:
a) The dogs ALL should have been petted.
b) *The dogs should have been ALL petted.
a) There seems to be no room for a possible landing site of the NP subject the dogs between [Spec, AgrP] and the head [Agr0] - or [Spec, IP] and [I0] if we don't take into account Split-IP hypothesis.
Where does all get stranded in a) in the syntax tree?
b) Why all cannot be stranded there? Theoretically, that position could be either be [Spec,VP] of the verb pet or [Spec,IP] of the participle inflection of (pet)-ted.
How does the theory account for the ungrammaticality of b)?