In fact regret is just the difference between maximum possible reward and the actual reward received and the project is about optimization.
There are two things to learn from this situation. The first is that just because some numerical measure is called "regret" it doesn't mean it has anything to do with the common use of the term. Secondly if you are going to invent an AI technique then picking emotive words for your jargon is a good way to ensure publicity."
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