C.29:7.5 - Realize a capacity bound with a shared stock of cards

Three unique admission cards can support a three-visitor bound when their possession and transfer rules control entry. C.29.3:5.3 follows free, reserved, inside and awaiting-return states. The free-card count gives a sufficient occupancy bound during handover; an occupancy equality additionally needs the intermediate states. A second entrance must share or partition the same stock. The worked construction shows how copying the stock defeats the bound and how controlled transfers restore it.