A field operator [phi](f) affiliated to M(D) is said to satisfy an [L.sup.cosh-1] regularity restriction if the strong product [[phi].sub.cosh-1] [(h).sup.1/2] [phi] (f) [[phi].sub.cosh-1] [(h).sup.1/2] is a closable operator
for which the closure is [tau]-measurable; that is, the closure is an element of the space [??] (h is the uniquely determined unbounded operator affiliated to M, while [phi] stands for the fundamental function associated with the Orlicz space [L.sup.cosh-1]).
Furthermore, since the analysis operators happen to be unbounded, we restrict ourselves to closable operators
for a minimal controllability on the process.