# Foundational perspective: embedded observables and invariants

SFT is built around a methodological constraint:

- objects are studied together with the structure that makes them observable and comparable
- claims are expressed through invariants and auditable decision rules rather than informal intuition

Syncré is the concrete layer where this constraint becomes checkable.

A global instant is represented by a slice Σₛ and a phase field Φ|Σₛ into a circle or torus.
Coverage, coupling, and stability are then statements about the phase field as an embedded observable on a declared domain, not about an isolated point.

This perspective is optional for using the engine and the certificates.
All formal content needed for verification is contained in the contract, predicate spec, and the main papers in `finish_ready/`.
