It would be sufficient to define l to be the pair POS, A -the inclusion of η h , η m and L adds redundant information that can be recovered from the set E, and other dependencies in D-but it will be convenient to include this information in the label.
it is important that given this definition of l, it is possible to define a function GRM(l) that maps a label l to a triple of nonterminals that represents the grammatical relation between m and h in the dependency structure.