User defined Ix instances potentially unsafe

[Matt Harden]

Matt Harden wrote:

> blah, blah, blah, bug in the Library Report, blah, blah...

OK, so I failed to read the Library Report.  It clearly states:

> An implementation is entitled to assume the following laws about these operations: 
> 
>         range (l,u) !! index (l,u) i == i   -- when i is in range
>         inRange (l,u) i == i `elem` range (l,u)

So my "bug" is only in my mind.  Sorry for bothering everyone.

Regards,
Matt