The reason I didn't simply use Scheme's gensym is that it would have imported the concept of interning into Arc with it. That has always seemed rather a hack to me. It may turn out to be the best solution, but for now I want to take more time to think about it.
You could come up with a new "subtype" of symbols which is reserved for gensymed symbols -- then use some mapping of unique names for new such gensyms (say, a counter), and then use some new syntax like `__name' to evaluate to these things (assuming that you want code to be able to write such gensyms literally)...
But doing all of that is equivalent to just creating gensyms as done now, with a `__' prefix -- so if you really want that last property then nothing needs to be changed (perhaps only the `gs' prefix)...
