Explicit and implicit knowledge in approximate reasoning and cognitive modeling.

Humans acquire knowledge interacting with environment. Generally people use two types of knowledge bases: explicit and implicit. The former induced externally and imposed by society. It consists of publicly known noncontradictory propositions. Implicit knowledge, on the other hand, is that unique to the individual and permits degree of conflict. Both types of knowledge are using approximate reasoning. The former is based on deduction, whereas the latter on induction. In deductive reasoning inferences are based on reinforcement of constrains. The models for this type of reinforcement can be based on strong entailment. The spirit of strong entailment is to remove troublesome inferences if the conflict arises. In entailed proposition maximum membership grade is no greater than maximum membership grade in premise. Inductive reasoning is one where inferences are based on removing constrains. It can be modeled through other inference mechanism in approximate reasoning, e.g. weak entailment. This framework can be used to provide a psychoanalytical cognitive model of human mind where implicit knowledge represents 'It', and explicit knowledge constitutes 'Super-Ego'.