Beyond the Indus Threshold Independent Constraint Verification, Structural Closure, and Corpus-Wide Decipherment

This monograph presents a corpus-wide structural analysis of the Indus script and demonstrates the achievement of formal structural closure within the known inscriptional record. Using the standard Mahadevan sign identifiers as a stable reference framework and analysing the full set of structurally legible inscriptions published to date, the study establishes a finite, rule-bound grammatical system governing sign position, combinatorial structure, and sequence generation. The work proceeds by cumulative constraint application: positional immovability, template regularity, entropy collapse, and negative-space verification. Together, these demonstrate that all attested inscriptions are generable by a closed system and that the system produces no unattested structural combinations within the corpus. Decipherment is redefined operationally as the point at which a script’s internal structure becomes fully specified and falsifiable, independent of semantic translation. In this sense, the Indus script is shown to meet the structural threshold for decipherment. Phonetic admissibility is treated as strictly downstream of closure and is addressed only within the constraints imposed by the established grammatical system. This study contributes a methodological framework for evaluating undeciphered scripts and provides a falsifiable structural baseline against which future phonetic or functional interpretations must be tested.