Title: Mazayi Ma Mandombe – Rotational-Square Equivalence (RSE): Formal Mathematical Proof Appendix

This document contains the formal mathematical derivation and proof of the Rotational-Square Equivalence (RSE) axiom within the Mandombe geometric formalism. It establishes RSE as a universal metric primitive compatible with Hilbert space structure, isometry abstractions, and norm-preserving transformations. This proof annex is intended to accompany the canonical monograph and the Norme standard, providing the formal validation layer that demonstrates that RSE is consistent, well-formed, and mathematically admissible as a primitive metric law.