Derivation currently treated by the extraction process (required for the iterative analysis extraction)
Node of the grammar right part tree of the available continuations of the current derivation. It's the unique item identifier
Total number of interpretations associated to the item (and its sub-items)
Maximum (or Viterbi) probability of the item
The next item of the list (NULL if there is no item left)
Total (or inside) probability of the item
1.4.7