This makes it possible to cancel out an operation with the aid of a relationship between the relations addiction

摘要

The invention relates to a method for cancelling an operation with the aid of a dependency relationship between operations. It includes the following steps: fixing a condition for the existance of inverse operations corresponding to all the operations, producing a sequentially ordered relationship between the operations when the above condition is satisfied, and cancelling an operational state produced by the operations already carried out by using the sequentially ordered relationship between the operations. This method may be applied to a system for producing models, to a version control system for software, and to a system making it possible to produce a certain operational state by application, to the system, of instructions making it possible to carry out an operation such as a shaping or editing operation. Figures 6a to 6e show successive operations for producing a model; Figures 6f and 6g show respectively the cancellation of the operation carried out in Figure 6b and the direct production of another form of groove on the lower face of the part. IMAGE