# Scope and Non-Claims

## Scope

This engine is designed to be read as a certification engine engine.

- RU is the engine.
- Host structures are inputs.
- Strong conclusions live in JSON certificate objects.

## Inputs that fit the engine

The engine applies to finite reductions that provide:

- a finite constraint graph
- nonnegative template operators on a cone
- an optional cost model

Examples in the engine use fusion matrices and simple projection constraints because they are canonical host structures with positivity.

## Outputs

The engine emits exactly two kinds of outcomes:

- contraction certificates with explicit rates and robustness tolerances
- obstruction certificates with finite witnesses (OG1–OG4)

## Non-claims

- No claim is made that any given string compactification is physically realized.
- No claim is made that the full landscape can be reduced to a finite positivity instance.
- No claim is made that sector projections used in OG2 examples correspond to a physically consistent boundary condition. The point is that RU detects inconsistency when it exists.

## Why this scope is enough for a 

The  value is methodological:

- universality becomes decidable and auditable on the finite reduction class
- the engine provides a reusable certificate technology rather than a new narrative
