1.3 The deterministic finite automaton

Mathematically speaking, the Selmo-SEQ is a deterministic finite automaton (DFA). A DFA is a concept from computer science that has been used for decades in formal language analysis, compiler technology, and flow control.

It consists of:

• a finite set of states,

• a start state,

• transition rules, which define when to switch from one state to the next,

• and a transition function, which describes which signals or inputs trigger that change.

Selmo applies this principle to control engineering. The switching network (the “Sequence Engine”) plays the role of the automaton. The inputs come from sensors, pushbuttons, or computed signals. The outputs control actuators, valves, motors, or logical functions.

What is special about Selmo is that these transition rules are not arbitrary but was standardized are. They read:

IF (AR = 1 AND ¬I AND ΣS = 0) THEN Next State

This condition is universal. It means:

• AR = 1: The automatic release is active.

• ¬I: There is no interlock (no safety fault).

• ΣS = 0: All ongoing actions (sequence checks) are satisfied.

Only when these three conditions apply simultaneously does the switching network proceed. This makes the process calculable, safe, and reproducible — the machine follows an exactly defined logic.