Cover hauv topology A subcover ntawm C yog ib subset ntawm C uas tseem npog X. … Ib cover ntawm X yog hais tias yog point finite yog tias txhua point ntawm X yog muaj nyob rau hauv tsuas yog finitely ntau sets nyob rau hauv cover.
Dab tsi yog Subcover hauv topology?
subcover (plural subcovers) (topology) A cover which is a subset of another cover. Lub sijhawm qhib npog cov lej tiag; qhov qhib ncua sij hawm ntawm daim ntawv (x, x + 1) yog subcover.
Nkauj kho siab yog dab tsi?
Ib lub ntsej muag zoo nkauj yogib qho npog los ntawm cov teeb pom kev zoo ntawm thaj. Ib lub finite qhib npog yog ib qho qhib npog nrog ib txheej txheej ntawm thaj ua rau thaj. Finite qhib npog tshwm nyob rau hauv lub ntsiab lus ntawm compact topological chaw.
Puas yog cov subcovers finite qhib?
Lub ntsiab txhais tiag tiag ntawm compactness yog qhov chaw yog compact yog txhua qhov qhib npog ntawm qhov chaw muaj qhov kawg subcover. … Ib daim npog qhib yog ib phau ntawv qhib (nyeem ntxiv txog cov ntawm no) uas npog qhov chaw. Ib qho piv txwv yuav yog txheej ntawm txhua lub sijhawm qhib, uas suav nrog tus lej tiag.
Puas yog txhua qhov kev txiav txim siab compact?
Txhua qhov kev txiav txim siab is compact. TEEB MEEM: Ib qho finite teeb yog ob qho tib si bounded thiab kaw, yog li yog compact. Lub teeb {x ∈ R: x − x2 > 0} is compact.
