Distributional Structure in Voynich B: A Constraint-Based Grammatical Analysis of Beinecke MS 408

The Voynich manuscript (Beinecke MS 408) is a fifteenth-century codex written in an undeciphered script that has resisted linguistic analysis for over a century. This paper presents the first constraint-based grammatical analysis of one of its two linguistic varieties (Currier B), based on quantitative methods applied to the complete EVA transcription. We independently confirm the Currier A/B distinction through unsupervised classification (95.9% agreement, N=196 pages) and demonstrate that the two varieties constitute separate linguistic systems sharing a common lexical pool but employing independent grammars (Hypothesis Z). Predicate rate, the single strongest discriminating feature (83-fold difference), remains stable across scribes and manuscript sections, supporting its interpretation as a system-level feature rather than a scribal or genre effect. For Voynich B, we identify: (1) a two-dimensional distributional grid comprising positional markers (ol/ok and or/ot) with selectional asymmetry and a consistent directional tendency toward paragraph-level exclusivity; (2) a morphological system including an argument-deriving prefix (q-), a predicativizing suffix (-ch), and systematic morphophonological constraints (8 of 9 tested constraints significant after Bonferroni correction); and (3) a syntactic structure organized around predicate-bearing lines with hierarchical predicate stacks. These findings are consistent with a constructed language hypothesis and provide a framework for future semantic interpretation.