"A process in which the chance occurence of appropriate of inappropriate behavior is positively or negatively reinforced, respectively" (A. H. KLOPF, 1972 ,p.59).
According to KLOPF: "Such a mechanism eventually produces a network that, to some degree, models the organism and the environment. As the model becomes increasingly refined, the statistical aspect of the adaptive process becomes less apparent and behavior appears more directed" (Ibid.).
Using KLOPF's terminology, as well as ASHBY's, one may say that the heterostat tends towards the homeostat when its behavior tends to stability. On the other hand, they stabilize because any system must become autopoietic: its coherence can be maintained only if, in some defined environment, some types of behavior are either impossible, prohibited, strongly constrained or, on the contrary highly favored.
The system goes on, constructing progressively its own algorithm, by a trial and error process. Besides, it constructs this algorithm in a specific way, because it does not start from scratch, but from some archetype, which allows only for a pre-defined repertory of admissible variations.