The Rule of the

When a tie is made between two individuals and once the dealt material is simple and inseparable،the tie is called simple and irrevocable. If the parties of the tie are more than two people or its subject is various،e. g.، when it is understood that one of the vendors is not satisfied with selling his/her article or if it is found out that one of sold things belong to other person،in this case the tie is separable،and the mentioned tie is divided into two separable ties such as a valid and invalid ties. The paper is an attempt to study carefully the above mentioned rule In different respects: the current of the rule in agreements and ties،the explanation of the rule implications،the rule documents،the dissolving case in the rule،the effects of dissolution of one tie into two،the problems of the rule،and the response to them،as well as the application of the rule in the statutes and the imposed laws.