Fig. 3.
The PRMs of an oligosacchrides. (a) An oligosaccharide consisting of 12 glucoses. The glucose residues are indexed according to the partial order of nodes of the tree, from leafs to the root. For any two residues ri and rj, if ri is within the subtree rooted by rj, i must be indexed smaller than j.(b) The subtrees rooted by residues r3, r9, r10, r11.