I wrote:
	> The real question is the semantics of BlockContextComposite.
	> In some of the examples, the comma "means" AND, in some OR,
	> in some a sort of NOT-AND, in some a sort of NOT-OR

Andres Valloud <sqrmax at prodigy.net> replied:
	
	Comma does not mean any of the above.
	
Did you notice the scare quotes?  Admittedly comma-for-blocks doesn't
MEAN any of those things, but the human reader has to understand it
as being USED for those purposes.

	> We already _have_ messages that summarise "composites" in various
	> ways, and they apply to collections. <snip>
	
	Those messages don't allow comma.
	
The point is that they don't need to.
	
I rather like the #and: #and:and: #and:and:and: #and:and:and:and: suggestion.
It's readable and "do the simplest thing that could possibly work".