13. A computer-readable non-transitory storage medium comprising executable instructions that, when executed by a computer system, cause the computer system to: perform semantico-syntactic analysis of a natural language text to produce a semantic structure representing a set of semantic classes; associate a first semantic class of the set of semantic classes with a first value reflecting a specified semantic class attribute; identify a second semantic class associated with the first semantic class by a pre-defined semantic relationship; associate the second semantic class with a second value reflecting the specified semantic class attribute, wherein the second value is determined by applying a pre-defined transformation to the first value; identify a third semantic class associated with the second semantic class by the pre-defined semantic relationship; and associate the third semantic class with a third value reflecting the specified semantic class attribute, wherein the third value is determined by applying the pre-defined transformation to the second value; evaluate a feature of the natural language text based on the first value and the second value; determine, by a classifier model using the evaluated feature of the natural language text, a degree of association of the natural language text with a particular category of a pre-defined set of categories; and perform, using the degree of association, a natural language processing operation.
18. The computer-readable non-transitory storage medium of claim 13 , wherein applying the pre-defined transformation comprises multiplying the first value by a pre-defined multiplier.