• affiliate@lemmy.worldOP
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      1 year ago

      it’s the “order type” of a well ordering on a set. so, given a set X with a total ordering R, type(X,R) is the unique ordinal isomorphic to (X,R)

      • bort@feddit.de
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        1 year ago

        what’s with the square at the end? isn’t that usually for proofs?

        • affiliate@lemmy.worldOP
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          1 year ago

          yeah but sometimes when the textbook authors are feeling particularly mischievous they’ll just put them in random places. and sometimes they’ll even skip the proofs but keep the square.