[whateverer]

@mitsuhiko Not gonna happen ;) Forbidding shadowing altogether is a huge win, and a huge conceptual simplification.

Poppycock. It doesn't get simpler than

  a. newly bound variables are new
  b. any variable which wasn't bound in the present scope must be bound in a enclosing scope.

If your language makes it much more complicated than First Order Logic (http://cnx.org/content/m12081/latest/), you're doing it wrong.

Of course, it's kind of socially acceptable to get wrong because a lot of language designers didn't think it through and used the same operator for both binding and reassigning a variable (i.e. '=').