In set theory, ib tug ordinal number, or ordinal, is one generalization of the concept of a natural number uas yog siv los piav txog ib txoj hauv kev los npaj cov khoom sib sau ua ke, ib qho tom qab.
Yuav ua li cas hu ua ordinal?
Ib tug naj npawb yog tus lej uas qhia txoj haujlwm ntawm ib yam dab tsi hauv ib daim ntawv, xws li 1st, 2nd, 3rd, 4th, 5th thiab lwm yam. Feem ntau cov lej xaus rau " th" tsuas yog rau: ib ⇒ thawj (1st) ob ⇒ thib ob (2nd) peb ⇒ thib peb (3rd)
Lub ntsiab lus ntawm kev ua lej hauv lej yog dab tsi?
In common use, ib tug ordinal tooj yog an adjective uas piav txog tus naj npawb ntawm qhov khoom, piv txwv li, thawj, thib ob, thib peb, thiab lwm yam. tus naj npawb ib txwm (qee zaus hu ua "ordinal" luv luv) yog ib tus lej hauv Georg Cantor qhov txuas ntxiv ntawm tag nrho cov lej.
piv txwv ntawm tus lej lej yog dab tsi?
Cov lej yog cov lej uas hais txog txoj haujlwm ntawm cov khoom. Piv txwv li, " Cov ncuav qab zib khaws cia hauv 3rd tub rau khoom saum toj ", "Cov txiv kab ntxwv hnav yog 7 th ib ntawm sab xis", "Lub pob ncaws pob khaws cia rau hauv 3 rd thawv ntawm sab laug".
txhais li cas los ntawm cov lej thiab cov lej?
Cardinal lej qhia 'peb' ntawm ib yam dab tsi, lawv qhia kom muaj nuj nqis. Cov naj npawb qhia qhov kev txiav txim ntawm cov khoom li cas, lawv qhia txoj haujlwm lossis qib ntawm qee yam. … Peb siv cov lej lej rau hnub tim thiab qhov kev txiav txim ntawm ib yam dab tsi (xav tias ordinal=xaj).
Ordinal Numbers | Mathematics Grade 1 | Periwinkle
