Logical implication.
This is the relation between the antecedent (subject) and
conclusion (object) of a rule.
The application of a rule to a knowledge-base is as follows.
For every substitution which, applied to the antecedent,
gives a formula which is a subset of the knowledge-base,
then the result of applying that same substitution to the
conclusion may be added to the knowledge-base.
related: See log:conclusion.
(See the CWM manual for command line options to determine how
rules from different sources are applied to and the results
added to various formula.)