Target-Relative Provenance Requests and Versioned Observation Contracts in Finite Legal Reply Systems of Shogi

Abstract

We study finite observation systems in which a visible value is always recorded, while one provenance coordinate is requested only on selected visible fibers. The omission event is typed as \(\NR\), rather than represented as a missing or null provenance value. For an episode system \((E,v,p,t)\), the target-ambiguity support consists of visible fibers on which the target \(t\) is nonconstant. If the optional provenance coordinate \(p\) separates the target inside every ambiguous fiber, then requesting precisely that support is necessary and sufficient. This gives an explicit greatest target-sufficient kernel within the restricted family of request-generated observations. The general coarsest-factorization principle is classical and has recently been emphasized through optimizer quotients; our result is a closed-form specialization to per-fiber typed provenance requests. The main theory concerns versions and extensions. We characterize the maximal extension class on which a fixed request declaration remains semantically sufficient, distinguish decoder extension from frozen-decoder replay, and prove canonical forgetting maps under support expansion. A reverse record lift exists exactly when provenance was already constant on every newly requested old fiber. Even then, it is not request-history preserving: retroactively replacing \(\NR\) by \(\Obs\) falsifies the historical observation event. Thus request debt creates a directional version-migration barrier. The forgetting maps compose, so realized record images form a contravariant system over request-support inclusion. We realize the theory in chronological legal-reply systems derived from five complete shogi records, treating Black and White separately. A route target distinguishes direct updates, redundant intermediate checkpoints, and effective intermediate checkpoints. Exhaustive finite audit covers 527,810 legal chronological episodes. Extending a direct-only family creates 356 newly ambiguous synchronized payloads; 313 obstruct old-to-new record lifts and 43 permit only non-history-preserving lifts. Compressed total-action sequences fail to determine route effect in all ten systems, with 2,057 fractured subfibers. We provide abstract counterexamples, two proofs of the core support theorem, a multiple-coordinate nonuniqueness example, and reproducible code and data.