A portion of a country's territory not connected to the main part.
Different territories (countries, states, counties, municipalities, etc.) are represented by different colours and letters; separated parts of the same territory are represented by the same colour and letter, with a different number added to each smaller part of that territory (the main part is identified by the letter only).
- A:
- possesses 5 exclaves (A1, A2, A3, A4, and A5): it is impossible to go from the main part of A to any of these parts going only through territory of A; however:
- A1 and A2 are not enclaves: neither of them is surrounded by a single "foreign" territory;
- A1 is a semi-enclave and a semi-exclave: it has an unsurrounded sea border;
- A2 is an exclave of A: it is separated from A;
- A3 is an enclave: it is completely surrounded by B;
- A4 and A5 are counter-enclaves (also known as second-order enclaves): territories belonging to A that are encroached inside the enclave E;
- contains 1 enclave (E): "foreign" territory totally surrounded by territory of A;
- contains 1 counter-counter-enclave, or third-order enclave (E1).
- B:
- contains 2 enclaves (A3 and D).
- C:
- continuous territory, contains no enclave or exclave
- D:
- is an enclaved territory: it is territorially continuous, but its territory is totally surrounded by a single "foreign" territory (B).
- E:
- is an enclaved territory: it is inside A;
- contains 2 enclaves (A4 and A5), which are counter-enclaves of A;
- possesses 1 counter-enclave (E1), which is a counter-counter-enclave as viewed by A and contained within A5.
In
topological terms, A and E are each (sets of) unconnected surfaces, and B, C and D are
connected surfaces. However, C and D are also simply connected surfaces, while B is not (it has first
Betti number 2, the number of "holes" in B).