  The reverse engineering problem with probabilities and sequential behavior is
introducing here, using the expression of an algorithm. The solution is
partially founded, because we solve the problem only if we have a Probabilistic
Sequential Network. Therefore the probabilistic structure on sequential
dynamical systems is introduced here, the new model will be called
Probabilistic Sequential Network, PSN. The morphisms of Probabilistic
Sequential Networks are defined using two algebraic conditions, whose imply
that the distribution of probabilities in the systems are close. It is proved
here that two homomorphic Probabilistic Sequential Networks have the same
equilibrium or steady state probabilities. Additionally, the proof of the set
of PSN with its morphisms form the category PSN, having the category of
sequential dynamical systems SDS, as a full subcategory is given. Several
examples of morphisms, subsystems and simulations are given.
