Un marco axiomático para sistemas de obstrucción indexados canónicamente

We establish a closed axiomatic framework for canonically indexed obstruction systems acting on a discrete index axis. The aim is purely structural and foundational: no new arithmetic results are proved and no specific classical problem is addressed. The framework isolates the minimal geometric, congruential, p–adic, and Archimedean principles common to a broad class of indexed sieve constructions and congruential exclusion mechanisms. From these axioms we derive global structural consequences governing finite realizability, effective obstruction bounds, and deterministic non–coverage on the index axis. The purpose of the paper is to provide a stable axiomatic reference layer upon which subsequent arithmetic and dynamical applications may rely without repeating foundational constructions.