Mezha mnozhini ce vsi taki tochki yaki perebuvayut yak zavgodno blizko i do tochok v mnozhini i do tochok poza neyu 1 Mnozhina svitlo sinya i yiyi mezha temno sinya Oznachennya RedaguvatiNehaj ye topologichnij prostir X T displaystyle X mathcal T i pidmnozhina A X displaystyle A subset X Tochka x 0 X displaystyle x 0 in X nazivayetsya grani chnoyu tochkoyu pidmnozhini A A yaksho dlya bud yakogo yiyi okolu U T U x 0 displaystyle U in mathcal T U ni x 0 spravedlivo U A U A displaystyle U cap A neq emptyset U cap A complement neq emptyset mnozhina vsih granichnih tochok mnozhini A A nazivayetsya mezheyu i poznachayetsya A displaystyle partial A Ekvivalentni oznachennya Mezha mnozhini A A ce ta chastina zamikannya A A sho ne vhodit v yiyi vnutrishnist x A A 0 displaystyle partial x bar A A 0 peretin zamikannya samoyi mnozhini A A ta zamikannya yiyi dopovnennya X A displaystyle X A x A X A displaystyle partial x bar A cap overline X A Primitki Redaguvati Arhivovana kopiya Arhiv originalu za 20 veresnya 2018 Procitovano 19 veresnya 2018 Posilannya RedaguvatiJ R Munkres 2000 Topology Prentice Hall ISBN 0 13 181629 2 S Willard 1970 General Topology Addison Wesley ISBN 0 201 08707 3 Ce nezavershena stattya z geometriyi Vi mozhete dopomogti proyektu vipravivshi abo dopisavshi yiyi Otrimano z https uk wikipedia org w index php title Mezha topologiya amp oldid 35358048
