Computation is a step in the computer, here in the atomistic model, which evaluates one term of the model, at a time.

See the definition at Wiki: Computation is a general term for any type of information processing. This includes phenomena ranging from human thinking to calculations with a more narrow meaning. Computation is a process following a well-defined model that is understood and can be expressed in an algorithm, protocol, network topology, etc. Computation is also a major subject matter of computer science: it investigates what can or cannot be done in a computational manner.

Each computation, which traverses an atomistic model is a step in the corresponding automaton.

Computable_FunctionFIGURE 6.

A computation can be either a transformer or an acceptor (see autoamata theory).

The formalism of a register machine regarding a single source code element, which is the foundation for the ModelWare approach, is especially
interesting (FIGURE 6). If the logic of each element can be defined by a single structure, in the figure f, which has a number of arguments m1 to mk, then it is
possible to build an abstract machine for each mathematical function to execute the corresponding computation.

This computation model is useful for any deterministic expression. It is useful for any logic expression, too. This formalism can be extended to cover the
whole syntax of programming languages. However, there are some exceptions and problems in modeling logic paths and real-time programs. The
Entscheidungsproblem (Turing, 1936) is a well-known example; it indicates that it is not possible to show that any freely selected program with a given set of
inputs consisting of arguments m1…mk could terminate and produce a certain output value n.