Query terms, unless they are delimited with quotation marks to be treated as exact phrases, are expanded by the MDEX Engine using stemming.

The expansion for stemming applies even to terms that are the result of thesaurus expansion. A stemmed query term is an OR expression of its word forms.

For example, if the query pentium laptop was thesaurus-expanded to:

(pentium OR intel) AND (laptop OR notebook)

it will be stemmed to:

(pentium OR intel) AND (laptop OR laptops OR notebook 
OR notebooks)

assuming that only the improper nouns have plurals in the word form dictionary.