[R] Superimposing y-variables in Lattice formulas

[hadley wickham]

Hi Stavros,

> I think we're talking past each other on the question of the semantics
> of formula operators, and it's probably not productive to continue.  I
> would guess that the underlying issue is that we come from different
> communities, and so have different background assumptions.  Perhaps
> it's the old MIT vs New Jersey story
> (http://www.jwz.org/doc/worse-is-better.html) -- after all, S/R does
> come out of the Bell Labs community, and I was in the MIT Lisp
> community many decades ago....

I think the simple answer is that there are no general function
semantics.   Knowing what + does gives you no insight into what *
does.  Know what * does, gives you no insight into what / does.  There
is no algebra that unifies the operators.

Hadley

-- 
http://had.co.nz/