Your Wish is My Command

148 Chapter Seven Bringing Programming by Demonstration to CAD Users

"naming" of further objects. Consequently, each reference to these shifted

variables has to be modified. Moreover, debugging the suppression of ac-

tions that generate objects requires the checking and the possible invalida-

tion of further actions that use these particular objects. All this manage-

ment must be performed by the PBD manager.

Another consequence is more important. The validity of example-based

programming is based on one prerequisite: it is assumed that execution

will

repeat the example. Values may change, but actions ...