Dab tsi yog qhov null khoob teeb?
Dab tsi yog qhov null khoob teeb?

Video: Dab tsi yog qhov null khoob teeb?

Video: Dab tsi yog qhov null khoob teeb?
Video: Leng Yang - Yog Vim Dab Tsi (Official Full Song | Nkauj Tawm Tshiab) 2020/05/24 2024, Kaum ib hlis
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Hauv kev ntsuas kev xav, ib qho teeb qhov ntsuas 0 yog hu ua a null teev (los yog tsuas yog ntsuas-zero teeb ). Hos ib teeb txhais tau tias: Hauv lej, thiab tshwj xeeb tshaj yog teeb txoj kev xav, 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.

Kuj nug, dab tsi yog ib qho null lossis khoob?

Hauv teeb theory lub tswvyim ntawm ib teeb los yog null teev yog ib qho tseem ceeb heev thiab nthuav. Nws txhais tau li no: “a teeb uas tsis muaj cov ntsiab lus hu ua teeb los yog null teev ”, thiab qee zaum nws yog hu ua void teeb los yog nqus teeb . Piv txwv li, lub raj mis tsis yog ib qho khoom zoo rau cov hniav nyiaj hniav kub teeb.

Tsis tas li ntawd, puas yog null teeb ib lub caij ntawm null teeb? Yog, lub teeb { teeb } yog a teeb nrog ib leeg keeb . Ib leeg keeb yog cov teeb.

Yog li, dab tsi yog qhov null teeb nrog piv txwv?

Cov null teev , kuj hu ua qhov khoob teeb , yog teeb uas tsis muaj cov ntsiab lus. Rau piv txwv , xav tias ib tug neeg nug koj kom nrhiav tau teeb ntawm tag nrho cov neeg laus uas muaj hnub nyoog qis dua tsib xyoos.

Ib qho khoob khoob txhais li cas?

Hauv lej, the npliag teeb yog lub tshwj xeeb teeb tsis muaj cov ntsiab lus; nws qhov loj me lossis cardinality (suav cov ntsiab lus hauv a teeb ) yog zero.

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