Isn't this extremely simple to fix?

#= is implemented in terms of start, step, and last.

So why not implement #hash as

^(start hash bitXor: step hash) bitXor: self last hash

Then in the postscript do a

HashedCollection rehashAll

and that should be it, right?

I did a quick check using

Dictionary allInstances select: [ :dict | dict keys anySatisfy: #isInterval]

and the system seems fine after that.

- Bert -