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Here each time a new window opens, the old window is closed, i.e. the same input element is responsible for starting and closing a window. The output contains two windows, one from 1 to 5 and one from 5 to 11. As the final window is not closed, the out starting from C (at 11) is discarded. Use DrainAtDone = true, to allow the output of these elements.
Using a start and an end predicate and keeping the ending element:
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