- #1
mathsss2
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Show that the following statements are equivalent for any topological space [tex](X, \tau)[/tex].
(a) Whenever [tex]A, B[/tex] are mutually separated subsets of [tex]X[/tex], there exist open disjoint [tex]U, V[/tex] such that [tex]A \subseteq U[/tex] and [tex]B \subseteq V[/tex].
(b) [tex](X, \tau)[/tex] is hereditarily normal.
Background:
Definition- Sets [tex]H[/tex] and [tex]K[/tex] are mutually separated in a space [tex]X[/tex] if and only if [tex]H \cap \overline{K}[/tex] [tex]= \overline{H} \cap K = \emptyset[/tex]
(a) Whenever [tex]A, B[/tex] are mutually separated subsets of [tex]X[/tex], there exist open disjoint [tex]U, V[/tex] such that [tex]A \subseteq U[/tex] and [tex]B \subseteq V[/tex].
(b) [tex](X, \tau)[/tex] is hereditarily normal.
Background:
Definition- Sets [tex]H[/tex] and [tex]K[/tex] are mutually separated in a space [tex]X[/tex] if and only if [tex]H \cap \overline{K}[/tex] [tex]= \overline{H} \cap K = \emptyset[/tex]