Dab tsi yog qhov khoob teeb tsa hauv kev txheeb cais?
Dab tsi yog qhov khoob teeb tsa hauv kev txheeb cais?

Video: Dab tsi yog qhov khoob teeb tsa hauv kev txheeb cais?

Video: Dab tsi yog qhov khoob teeb tsa hauv kev txheeb cais?
Video: Koj saib kuv tsis muaj nqis - Nkauj tawm tshiab 2021-22 2024, Kaum ib hlis
Anonim

Empty Set . A teeb uas tsis muaj cov ntsiab lus hu ua ib teeb (los yog a null teev ). Saib ntxiv: Teeb thiab Subsets.

Ib yam li ntawd, koj yuav nug, dab tsi yog qhov khoob hauv lej?

Hauv lej , cov teeb yog qhov tshwj xeeb teeb tsis muaj cov ntsiab lus; nws qhov loj me lossis cardinality (suav cov ntsiab lus hauv a teeb ) yog zero. Qee qhov axiomatic teeb theories xyuas kom meej tias cov teeb tshwm sim los ntawm suav nrog axiom ntawm teeb ; Hauv lwm qhov kev xav, nws lub neej tuaj yeem txiav txim siab.

Ib yam li ntawd, vim li cas lub khoob khoob hu ua lub teeb? Qhov kev sib tshuam ntawm ib qho teeb nrog rau teeb yog cov teeb . Qhov no yog vim tsis muaj cov ntsiab lus hauv lub teeb , thiab ob qho tib si teeb tsis muaj cov ntsiab lus sib xws. Qhov no yog vim tsis muaj cov ntsiab lus hauv lub teeb , thiab yog li peb tsis ntxiv cov ntsiab lus rau lwm tus teeb thaum peb tsim lub union.

Kuj kom paub yog, dab tsi yog khoob teeb nrog piv txwv?

Cov null teev , kuj hu ua tus teeb , yog teeb uas tsis muaj cov ntsiab lus. Yog li ntawd, koj teeb tsis muaj cov ntsiab lus thiab yog cov null teev . Lwm tus piv txwv ntawm null teev yog cov teeb ntawm tag nrho cov lej uas tseem khib. Kom meej meej tus lej tsis tuaj yeem yog qhov khib thiab txawm, yog li tsis muaj cov ntsiab lus hauv qhov no teeb.

Puas yog 0 ib qho khoob khoob?

Cardinality ntawm lub Empty Set Ib tug txhais ua ntej raws li cov zauv suav tsawg tshaj li 5 muaj ib tug cardinality ntawm 4 vim hais tias nws muaj plaub yam: cov zauv 1, 2, 3, thiab 4. npliag set 0 vim cov teeb tsis muaj cov ntsiab lus. Hauv teeb sau ntawv, peb tuaj yeem sau | Ø| = 0.

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