The system contains two aspects: formal legal rules and informal customs. It is the result of a transaction. After the establishment of the system, a relatively stable pattern of interest is formed, resulting in institutional inertia. In this inertia, changes in customs and laws and laws The rules change slowly. Can it be derived from this text? ['No change will occur after the system is formed.', 'Institutional changes are spontaneous.', 'Institutional change is a gradual process.', 'With the improvement of the system, the change of the system will become slower and slower, or even "end".']