Problem with array updates

[Rolf-Thomas Happe]

You may ignore my previous reply which I recognise, now that I have sent
it, as -- rubbish.  I neither read nor thought carefully enough, I'm
afraid.

rthappe


> I can't mark the array as unique, for I would force the whole VEBTree type
> to be unique. In this case, I can't use the function createArray (not even an
[...] 
> If I instead use the VEBTree tyoe as descripted above (i.e., without uniqueness
> annotations), then I can use the createArray function, but I can't update it
> destructively: an expression with this form: