Formal ball
id:
formal-ball-308-12351601
title:
Formal ball
text:
In topology, a formal ball is an extension of the notion of ball to allow unbounded and negative radius. The concept of formal ball was introduced by Weihrauch and Schreiber in 1981 and the negative radius case by Tsuiki and Hattori in 2008. Specifically, if is a metric space and R + the nonnegative real numbers, then an element of B + = X × R + is a formal ball. Elements of B = X × R are known as generalized formal balls. Formal balls possess a partial order ≤ defined by ≤ if d ≤ r − s , identi
brand slug:
wiki
category slug:
encyclopedia
description:
Mathematical ball with unbounded or negative radius
original url:
https://en.wikipedia.org/wiki/Formal_ball
date created:
date modified:
2020-09-16T05:27:25Z
main entity:
{"identifier":"Q18207202","url":"https://www.wikidata.org/entity/Q18207202"}
image:
fields total:
13
integrity:
14