In the Statement "The Increment is the sum of all the Product Backlog items completed during a Sprint and the value of the increments of all previous Sprints"
do the words "and the value" indicate addition ?
If so, since the increments of the previous Sprints also contain the sums of all previous Sprints, one ends up with a factorial function.
My old fashioned Dictionary (goggle) describes an increment as just the additional part, i.e. here the sum of all Product Backlog items completed during a Sprint.
