s: Recently a series of studies that made by Oaksford suggested that Probability information has a strong influence on cognitive process of conditional inference so that it can be used to explain and predict peoples reaction in inference.

The application of disjunctive syllogism is indispensable to investigation,which has been proved by investigation practice for a long time.

Whether it is viewed in the light of inference mechanism or from the angle of premise constitution, in essence, dilemma belongs to fullconditioned hypothetical inference, and therefore should observe the rules of hypothetical inference, the socalled argument does not hold water that dilemma belongs to disjunctive syllogism and should observe the latter s rules.

It has approximation capability, and can satisfy modus ponens and other infer.

The rules of modus ponens are given and the main results of propositional calculus in two-valued logic.

Based on the possibility theory, this paper presents an inference model which contains the classical inferences, "modus ponens" and "modus tollens".

For both intuitionistic fuzzy hypothetical reasoning and intuitionistic fuzzy re.

The research was composed of two experiments, and the main aim was to explore the judgment criteria and specialties of children and adolescents when they tried to solve the hypothetical reasoning problems.

Though the association inference is relatively simple,it must observe some rules.