A.14:9.2 - PortionOf guards

ID	Requirement	Purpose
CC‑POR‑1 (Domain)	`PortionOf(x,y)` is valid only if the modelling scope declares at least one extensive measure μ for y (mass, volume, token count, byte size, wall‑time budget, etc.).	Prevents “portion” without a measure.
CC‑POR‑2 (Kind)	x and y SHALL share the same μ‑kind and compatible units (or an explicit conversion).	Prevents apples‑to‑oranges addition.
CC-POR-3 (Monotone additivity)	For disjoint portions `x ⟂ z` with `PortionOf(-,y)`, whose join is admitted under the same measure and boundary rule: μ(x ⊔ z) = μ(x)+μ(z).	Justifies the additive measure of that admitted join; additions, removals and boundary flows still need their applicable conservation account.
CC‑POR‑4 (Boundary)	For physical systems, the whole’s boundary encloses the union of portions; cross‑boundary flows are not portions.	Distinguishes stock vs flow.
CC‑POR‑5 (Non‑replacement)	When replacing a measured portion of y, state the removed and inserted amounts under their applicable measure and boundary rules, and test y’s identity under its governing rule. Add ComponentOf or ConstituentOf only when that separate structural or content relation obtains.	Avoids inferring another relation from a measured replacement.