The Is: An Ontological Framework v2.1 — Formal Mapping Layer A Type-Theoretic and Structure-Preserving Reconstruction of the I → D → S → A → F Sequence

This release presents The Is Framework v2.1, introducing the Formal Mapping Layer, a systematic extension of the Mapping Theory developed in v2.0. The framework begins from the ontological sequence I → D → S → A → F (Isness, Differentiation, Structure, Appearance, Feedback) and reconstructs this sequence through a type-theoretic and structure-preserving perspective. Building upon the foundational invariance principles established in earlier versions, v2.1 formalizes how interpretive mappings Πₓ may be evaluated, compared, composed, and subjected to explicit falsification criteria. Key contributions of v2.1 include: Formal Mapping Layer architecture (Fig.15) Four Mapping Invariance Principles (MDT-1–MDT-4) Sequence Order Preservation Ground Invariance Feedback Closure on Derived Layers Partial Structure Preservation Structure-preserving mappings across: Structural Differentiation Cosmology (SDC) Topological Latent Manifold Model (TLMM) Appearance–Behavior Framework (ABF) Compositional mappings Πᵧ ∘ Πₓ and interpretive composition analysis Formal Mapping Falsification Tests (C7–C9) Order Violation Ground Drift Feedback Leakage Strong / Partial / Weak mapping classification Developmental roadmap:v1.1 → v2.0 → v2.1 → v3.0 The framework remains explicitly interpretive and exploratory. The mappings presented here are intended to preserve generative structure and logical relationships and do not claim formal identity, reduction, categorical equivalence, or mathematical equivalence with any target framework. All figures, examples, compositional mappings, and falsification scores are illustrative demonstrations designed to support conceptual evaluation and future empirical development. This release includes the full manuscript, figures, and Python demonstration code used to generate Figures 15–18.