3001
Thus the work reported addresses two robustness problems faced by current experimental natural language processing systems : coping with an incomplete lexicon and with incomplete knowledge of phrasal constructions .
 robustness problems, natural language processing systems; incomplete lexicon, robustness problems; incomplete knowledge of phrasal constructions, robustness problems
Please list all entity pairs containing a certain relationship in the given options.Output format is "word1, word2; word3, word4". 
Option: conjunction, feature of, hyponym of, used for, part of, compare, evaluate for 
Text: {0} 
Answer:
 robustness problems, natural language processing systems; incomplete lexicon, robustness problems; incomplete knowledge of phrasal constructions, robustness problems