bags? 2.5.x?

[Paul Rubin]

Arnaud Delobelle <arnodel at googlemail.com> writes:
> * For sets {x, y} union {y, z} = {x, y, z}.  The natural way of
>   extending this to multisets is having the union operator take the
>   max of the multiplicities of each element, i.e.

That certainly doesn't fit the intuition of a bag of objects.  I'd
think of the union of two bags as the result of dumping the contents
of both bags onto the table, i.e. you'd add the two vectors.

> * Similarly, for intersection one would take the min of
> multiplicities, i.e.

This is a reasonable interpretation I guess.

> A difference B = A - (A intersection B)

I think difference would mean subtraction.