Presenting the Formal Theory of Hierarchical Complexity

The formal theory of the Model of Hierarchical Complexity is presented. Complexity theories generally exclude the concept of hierarchical complexity; Developmental Psychology has included it for over 20 years. It also applies to social systems and non-human systems. Formal axioms for the Model are outlined. The model assigns an order of hierarchical complexity to every task, using natural numbers, establishing a quantal notion of stage and stages of performance. This formalizes properties of stage theories in psychology. The formal theory of the model enables extending the concept of hierarchical complexity to any field where tasks and their performances exist.