ABSTRACT
A tagged cell in a figure K is a pair (7 , i) where 7 is a cell contained in K and t is an endpoint of 7. For convenience we shall attribute to (7, t) properties of 7, e.g. length.
A division of a figure AT is a finite set K, of nonoverlapping tagged cells whose union is K. That is, a division is a partition with each member assigned one of its endpoints as its tag.
