# GVSS-09 — Multi-Provider Visual Capability Portfolios, Fallback Geometry, and Federated Reachability

## Core raw portfolio geometry

$$
\mathcal R(S)
=
\bigcup_{\nu\in S}
\mathcal R_\nu.
$$

## Core marginal provider gain

$$
\Delta_\mu(\nu\mid S)
=
\mu
\left(
\mathcal R_\nu
\setminus
\bigcup_{j\in S}\mathcal R_j
\right).
$$

## Core robust geometry

$$
\boxed{
\mathcal R_{\mathrm{rob}}^{(r)}(S)
=
\{
I:
m_S(I)\ge r+1
\}.
}
$$

## Core no-go

$$
\boxed{
\text{reachability redundancy}
\not\Rightarrow
\text{robustness redundancy}.
}
$$

## Provider diversity dimensions

- territory diversity;
- failure diversity;
- cost/availability diversity.

## Package contents

- canonical paper;
- literature audit;
- roadmap;
- GVSS-10 handoff;
- theorem index;
- tests;
- validation;
- checksums.