Monotonic

The monotonic property of a system or language indicates that once conclusions of the system are made, they cannot be amended at a later stage. First Order Logic is monotonic.

As this does not represent the kind of inference that is made in everyday life, it is clear that a model of artificial intelligence cannot be based on a logic which is monotonic.

A number of non-monotonic logics have been developed to model the use of defeasible inference. Defeasible inferences are made, which are inferences that may be retracted at a later stage in the light of new information.