Constants limit the category of situations.. The degree of complexity, the desired level of accuracy, the volume of production, materials or means available to accomplish

To ensure that the equation   Situations must be distinguished between class positions through some of the constants of nature with the following:

** All linked to the support or carrier status, or to offer or give the learner:

* The text of certain scientific, to a certain level of difficulty and a certain length (3 constants).

* Decree requires mathematical problem to three key processes. (2 constants)

* Impact of historic pattern, and a certain era (2 constants).

* .... Etc..

Example: In the technical drawing of the positions identified in 3 parameters:

* You must be available in 12 rooms and the interface at the most.

* You must be a flat interfaces.

* You must be a list of Ka angles.

** Can be associated with constants   The pattern of activity or task: the degree of complexity, the desired level of accuracy, the volume of production, materials or means available to accomplish .... etc..