1 COS-S - Collapsing-Structure Spacetime Model: The discrete kinematic base layer

This preprint introduces the Collapsing-Structure Spacetime (COS-S) model, the discrete kinematic foundational layer of the broader COS program. COS-S represents spacetime in terms of finite, ordered, weighted shell–filament and simplicial structures, where local metric and topological data are encoded through quantized labels and operator-theoretic objects. The publication develops the basic mathematical interface of the model: admissible shell configurations, quantized state spaces, discrete metric data, geometric and kinematic operators, operator algebra, curvature diagnostics, and compatibility conditions. Discrete collapse/transition steps are introduced at the kinematic level, while the full operational channel interpretation, dynamical closure, and detailed treatment of the classical limit are assigned to the related COS-QD, COS-QF, COS-CL, and further modules. The manuscript also discusses quasiclassical interpretation, conditional recovery of general-relativistic behavior, causality-related assumptions, proof-audit structure, and numerical cross-checking examples. These examples are intended to illustrate how classical, relativistic, and empirical connections may be investigated under stated assumptions, rather than to provide a complete phenomenological confirmation. This version contains the complete preprint in PDF format. Standalone source files and full computational code packages are planned for a later release.