Fractal Unit
The SU(4)-stage unit where internal generators allow closure to be searched internally and expressed as repeatable structure.
What the term means
A fractal unit is ECM’s name for the stage where internal generators become available and the unit can search for closure inside itself before expressing a stable result outward.
The book treats SU(4) as the first unit where meaning closes its loop inside the unit itself, which is why SU(4) becomes important for consciousness and subjectivity.
How it relates to the ECM
In ECM, the fractal unit turns recursion into internalized closure. Instead of merely containing a smaller motif, the unit can compare routes, close internal loops, and preserve a repeatable grammar.
That capability supports field-state memory, subjective consciousness language, and the later distinction between distribution and selection.
Why it is important to understand
The term matters because it is the point where ECM’s geometric ladder becomes able to carry internal state. Without it, consciousness pages and quantum-collapse analogies can sound like a jump rather than a continuation of the geometry.
It also keeps the model from treating all self-similarity as equal: prefractal recursion and fractal closure are different claims.
Book context
Book anchors: Chapter 1, Figure 1.4 describes SU(4) as a fractal with internal generators. Chapter 2 and Chapter 6 use SU(4) as the stable internal-closure checkpoint.
Read this as ECM vocabulary: it defines how the book uses the term inside its own conservation-first model. The term can overlap with standard physics or mathematics, but this page is explaining the ECM role first so readers do not lose the model-specific meaning.
Related ECM Diagram
This diagram belongs on the Fractal Unit page because it shows SU(4) as the point where internal generators let closure be searched internally and expressed as a stable repeatable structure.
The takeaway is that the fractal unit is where ECM begins treating internal closure as an available operation. That is why SU(4) becomes important for memory, subjectivity, and route selection later in the book.