On Sep 2, 6:48 am, pongba <pon... / gmail.com> wrote:
> This is a very general argument, what concerns me is ...
[snip]
> One might argue that [...] so the problem is moot.
> But then there's two more problems:
>
> 1. if we can't modify Matrix or Graph [...]
>
> 2. if '1' doesn't matter (because in ruby we actually can add new
> methods to an existing class), then can you please give another more
> qualified example?

What I hear you saying is:

  There's a problem with what Matz describes, because...
  OK, wait, that's not a problem.
  But then there's this other problem:
  Er, OK, that's not actually a problem either.
  Can you please show me what the problem is?

I think you've reasoned it out for yourself: there isn't a problem.
Even if it were, the two other responses in this thread show you ways
you could work around it if you needed to (which you don't).