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Declaring variables more than once

In article <17416@shemp.CS.UCLA.EDU> pierce@cs.ucla.edu (Brad Pierce) writes:
>Also, is one allowed to declare the same identifier more than once in the same
>lambda closure in official Scheme?...((lambda (x x) x) 1 2) 

There's no prohibition in R3RS, but that's an oversight.  R4RS will say that
(lambda (x x) ...) is an error.  Implementations will still not be required
to detect the error.

>And is it officially legal to "define" something more than once at top level.

There is nothing that says you can't.  Many people think that a <program>
should not contain multiple top level definitions for the same variable,
but that an interactive programming environment must allow re-definitions
as a debugging feature.  This is my view.

Peace, William Clinger