A common restructuring requirement is to make start-stop pairs out of points in a sequence. Given a sequence, 
, we would also want to create a paired sequence, 
. The first and second items form a pair. The second and third items form the next pair. When doing time-series analysis, we may be combining more widely separated values. In this example, the pairs are immediately adjacent values.
A paired sequence will allow us to use each pair to compute distances from point to point using a trivial application of a ...
