affiliate@lemmy.world to 196@lemmy.blahaj.zone · 2 years agoaddition rulelemmy.worldimagemessage-square19fedilinkarrow-up1208arrow-down10
arrow-up1208arrow-down1imageaddition rulelemmy.worldaffiliate@lemmy.world to 196@lemmy.blahaj.zone · 2 years agomessage-square19fedilink
minus-squareaffiliate@lemmy.worldOPlinkfedilinkarrow-up25·2 years 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-up11·2 years agowhat’s with the square at the end? isn’t that usually for proofs?
minus-squareaffiliate@lemmy.worldOPlinkfedilinkarrow-up15·2 years 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-up8·2 years 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.