limit point

noun

limit point

noun
1

Mathematics, Sciences, Topology Given a subset S of a given topological space T, any point p whose every neighborhood contains some point, distinct from p, which belongs to S.

  • is an example of a function having infinitely many essential singularities with a limit point at z=0. It is an easy matter to give examples of "elementary" functions whose singularities have a countable number of limit points.1962 [Ginn and Company], Einar Hille, Analytic Function Theory, Volume 2, 2005, American Mathematical Society, page 19, The function sin ( cot 1/z)
  • If z_0 is a limit point of S, then every ϵ-neighborhood of z_0 must contain infinitely many points of S.1970 [Macmillan], John W. Dettman, Applied Complex Variables, 1984, Dover, unnumbered page, Let S' be the set of limit points of a set S. Then the closure ◌̅S of S is S∪S'. […]
1 more example
  • As the next example shows, the set of zeros may well have a limit point not belonging to the domain.2006, Ivan Francis Wilde, Lecture Notes on Complex Analysis, Imperial College Press, page 153:
Synonyms
accumulation point, cluster point
Related terms
limit

Entry derived from the Wiktionary, under licence CC BY-SA 4.0 — list of authors.