utype questions

[Norman Gray]

Greetings, all.

I am often confused about what utypes are and are for, and when I
talk to people who claim to be less confused, they give a variety of
very certain and confident answers, which are rarely compatible with
each other.  These incompatibilities are not merely differences of
opinion about syntax, but appear to represent fundamentally different
perceptions of how utypes are scoped and designed.

I've collected a number of my puzzles about utypes into a single  
document, at

     http://nxg.me.uk/note/2009/utype-questions/

I don't think these are necessarily hard questions.  The problem is  
that some of them have multiple obvious answers, which are  
incompatible, and all of which I've heard represented as The  
Consensus.  I don't believe this is a secure basis on which to build a  
robust standard.

I hope the questions are useful.

All the best,

Norman


-- 
Norman Gray  :  http://nxg.me.uk
Dept Physics and Astronomy, University of Leicester