affiliate@lemmy.world to 196@lemmy.blahaj.zone · 10 months agoaddition rulelemmy.worldimagemessage-square20fedilinkarrow-up1207arrow-down10
arrow-up1207arrow-down1imageaddition rulelemmy.worldaffiliate@lemmy.world to 196@lemmy.blahaj.zone · 10 months agomessage-square20fedilink
minus-squareaffiliate@lemmy.worldOPlinkfedilinkarrow-up25·10 months agoit’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)
minus-squarebort@feddit.delinkfedilinkarrow-up11·10 months agowhat’s with the square at the end? isn’t that usually for proofs?
minus-squareaffiliate@lemmy.worldOPlinkfedilinkarrow-up15·10 months agoyeah 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.
minus-squareLem Jukes@lemm.eelinkfedilinkarrow-up8·10 months agoGive it up for op actually out here answering questions like a real live teacher.
What does type() mean here?
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)
what’s with the square at the end? isn’t that usually for proofs?
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.
Give it up for op actually out here answering questions like a real live teacher.