• Allow context-dependent models at each level
  
  
  
  
• Context-dependent subgraphs are stored in the SearchLevel as a pool of models and are traversed on an as-needed basis
  
  
• Support cross-symbol and symbol-internal models
  
  cross-symbol = (NP+VP, NP-VP+NP, VP-NP+NP, NP-NP+VP, VP-NP) symbol-internal = (NP+VP, NP-VP+NP, VP-NP)