> In <email@example.com>, Lennart Augustsson
> <firstname.lastname@example.org> writes:
> > ...
> >If objects can be distinguished when
> >you learn more about them then they were not equal in each and every
> Depends. Often computer programs are set up to model an approximation of
> the real world, with some selected attributes of the real world objects
> used in the description.
Actually, this kind of ``fuzzy'' modeling isn't supported explicitly
in pure functional languages, though it is surely relevant in praxis.
Pure FP's are useful if you have a formal model at hand (as in
compiler construction), or if you need one (as in safety-critical
Anything else can be done in pure FP's by using monads. But thats not
``referential transparency'' in the pragmatic sense discussed in this