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Is there a concept in math like ‘sufficient and locally necessary’ as in there are no other sufficient solutions within a delta neighborhood in the space or something? Like x=3 is a sufficient and locally necessary condition for x^2=9 because -3 is a discrete jump away.
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In math jargon, the set of solutions has a natural topology and wrt this topology the point x=3 is isolated - there’s an open neighborhood where it’s the only solution.
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