  Algorithms of inference in a computer system oriented to input and semantic
processing of text information are presented. Such inference is necessary for
logical questions when the direct comparison of objects from a question and
database can not give a result. The following classes of problems are
considered: a check of hypotheses for persons and non-typical actions, the
determination of persons and circumstances for non-typical actions, planning
actions, the determination of event cause and state of persons. To form an
answer both deduction and plausible reasoning are used. As a knowledge domain
under consideration is social behavior of persons, plausible reasoning is based
on laws of social psychology. Proposed algorithms of inference and plausible
reasoning can be realized in computer systems closely connected with text
processing (criminology, operation of business, medicine, document systems).
