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Borsigsteg (talk | contribs) →Temporal statements in the field of cultural heritage: Change title, add the distinction between events and their corresponding time intervals |
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In general, the number of different relations between ''n'' intervals, starting with ''n'' = 0, is 1, 1, 13, 409, 23917, 2244361... [http://oeis.org/A055203 OEIS A055203]. The special case shown above is for ''n'' = 2.
To see that the 13 relations are exhaustive, consider note that each point of <math>X</math> can be at 5 possible locations relative to <math>Y</math>: before, at the start, within, at the end, after. These give <math>5 + 4 + 3 + 2 + 1 = 15</math> possible relative positions for the start and the end of <math>X</math>. Of these, we cannot have <math>X_0 = X_1 = Y_0</math> since <math>X_0 < X_1</math>, and similarly we cannot have <math>X_0 = X_1 = Y_1</math>, thus giving us 13 possible relations.
===Composition of relations between intervals===
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