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For any country, U, the union of its regions is a disjoint universal set. The union of the regions is a
collection of a number of core, adjacent, and periphery regions that are non-overlapping as defined by
the extension and distance criteria of set theory. This is expressed in the following equation:
JCAP
U =∪ Rj =∑ Cj ∩∑ Aj ∩∑ Pj (Θcp > Θca ≥ Θap ) = 0 (9)
j =1 j =1 j =1 j =1
This equation states that for any country U the union of its administrative regions is equal to the sum
of its economic regions; core, adjacent, and periphery. These regions form a non-overlapping
collective. This model serves as a framework to study the dispersion of economic activity within the
geographic confines of a country.
4.2.1 Multi-Region CAP Model - A CAP cluster.
The basic CAP model, as illustrated in Diagram 1, is composed of three regions extending
outward along a radius consisting of a core, an adjacent, and a periphery region. It is, however,
entirely possible that there is more than one adjacent region within the first concentric circle around
the core. Likewise, the second concentric circle can consist of more than one periphery region. These
theoretical possiblities create a multi-regional CAP model as is illustrated in Diagram 2.
[Figure 2]
In Diagram 2, seven regions are superimposed on von Thünen’s concentric circles surrounding
a central region, C. There are four adjacent regions within the first concentric circle around the core.
The four adjacent regions are respectively labelled as: bcih, hijk, kjde, and bcde. The three periphery
regions in the second concentric circle are labelled as: abef, ghef, and ghba. A single core region with