[plt-dev] Release Announcement for v4.2.3, second call

On Nov 25, 2009, at 5:35 PM, Eli Barzilay wrote:

> I still need this...  (BTW, these items come from commit messages, so
> there might be things that I missed.)
> ----------------------------------------------------------------------
> 
> * added support for changing toolbar buttons based on the #lang
>  line, use that for #lang scribble/base
> 
> * 2htdp/universe stuff

nothing


> * Adding check-member-of and check-range

The unit test framework for the teaching languages provides 
mechanisms for checking 'random' "functions", i.e., "functions"
that may produce several different results for one and the 
same argument.