tupleset: experiment with sum of lengths instead of max
Currently tupleset::size
returns the max of the length. But we are interested in the monoid to be graded (see EAT p. 383), which requires the length to be additive. This invites to use another definition of size: the sum of the lengths.
Try that, and see how the results look like. In particular when showing polynomials. Ask Jacques what he thinks about that.
Actually, track the uses of size
to understand where we use it.