• affiliate@lemmy.worldOP
    link
    fedilink
    arrow-up
    23
    ·
    10 months 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
      link
      fedilink
      arrow-up
      11
      ·
      10 months ago

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

      • affiliate@lemmy.worldOP
        link
        fedilink
        arrow-up
        13
        ·
        10 months 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.

    • Lem Jukes@lemm.ee
      link
      fedilink
      arrow-up
      8
      ·
      10 months ago

      Give it up for op actually out here answering questions like a real live teacher.