Most interesting contributions to this issue.Thanks to everyone.
On the idea of taking a formal approach and involving HR, the organisation I work for is very traditional and celebrates characters of the type that is being placed next to me in the office The organisation is likely to pretend to do something about the issue, allow the issue to resolve itself between the individuals concerned or in more extreme cases, when one or other party resigns or does something that forces an escalation of the issue. Dare I say it, there is an element in the company culture that values and condones (secretly) the idea of people 'sorting it out between themselves' which generally means something something similar to when children have a 'playground showdown'.
As on many other occasions, I generally ride these situations out, however painful and unpleasant. While I am a sensitive person as Aspies are, and abhor violence and bullying, I am a large physically strong person so not likely to be physically intimidated. My biggest weakness is verbal assault. I just don't communicate well enough verbally. As a consequence, I weather a lot of verbal abuse until I crack and then I fly into an almighty rage. Happens regularly.
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On a clear day you can see forever