Re: [PATCH v3] Allow applying filters to summary consecutively

[Gregory Heytings]

> > Well, how about "Using a summary filtering command when a filtered 
> > summary already exists"?
> >
> > It may not be the best possible wordin, but at least it's correct and 
> > unambiguous.
>
> That's okay, thanks.  But it's only the beginning of my problem.  How do 
> you describe the effect of applying a filter on top of one or more other 
> filters?  Andrea wants to use "intersection", but I tend to think this 
> is too "mathematical" and too vague to explain clearly what happens. 
> What would be a good terminology for that?

I think there are two possibilities when adding another filter: either 
broadening the already existing filtering ("union" in mathematical terms) 
or narrowing the already existing filtering ("intersection" in 
mathematical terms).