Given a changefeed of the form:
stream.reduce(f).changes({includeInitial: <II>, includeStates: <IS>})
Assume that for the given f
, we know the following properties:
<f_BASE>
the initial accumulator forf
<f_APPLY>
a function from the accumulator and an element in the input table to a new accumulator<f_UNAPPLY>
the inverse of<f_APPLY>
in the accumulator