On one hand, the performance of Types2X suggests that information coming from the types occurring in the queries alone may not be enough to produce significant improvements in retrieval efficiency.
query types 'levi decomposition', 'parabolic subgroup', 'unipotent', 'irreducible representation','borel subgroup' Added Types 'reducible representation', 'regular element', 'conjugacy class', 'iwasawa decomposition', 'unipotent element', 'cartan decomposition', 'finite-dimensional representation ', 'unitary representation','cartan subgroup', 'centralizer', 'subgroup', 'triangular decomposition', 'jordan decomposition','parabolic subalgebra' TFIDF-Exp terms 'nilpotent', 'shredded', 'semi-simple', 'inflates', 'centralizer', 'pro-', 'puffed','engulfed', 'inflate', 'semisimple' Table 6: Topic 175 (MO post 90038): Text and types in query, types in query and dictionary, expansion types and sample TFIDF-Exp expansion terms (n=5, s = 2).