<p>From <a href="https://en.wikipedia.org/wiki/Interior_(topology)" rel="nofollow noreferrer">Wikipedia</a>:</p>

<blockquote>
  <p>In mathematics, specifically in topology, the interior of a subset S of points of a topological space X consists of all points of S that do not belong to the boundary of S. A point that is in the interior of S is an interior point of S. [...] If S is a subset of a Euclidean space, then x is an interior point of S if there exists an open ball centered at x which is completely contained in S. (This is illustrated in the introductory section to this article.)</p>
</blockquote>

CC BY-SA 3.0
2017-10-07T14:09:34.437Z
2017-10-07T14:09:34.437Z
Giskard
<p>From the paper: "Standard Auctions with Financially Constrained Bidders" - by Che and Gale. The authors describe an isobid curve as the curve that represents payments of the same value in a 2-dimensional plane (wealth and valuation). They state that:</p>

<p>"The isobid curves are negatively sloped and have no interior"</p>

<p>What does it mean that an iso curve has no interior?</p>

<microeconomics><mathematical-economics><auctions>
What does it mean when we say an iso curve has no interior?
tvbc
# What does it mean when we say an iso curve has no interior?

(Asked by: username_0 on 2017-10-07)

From the paper: "Standard Auctions with Financially Constrained Bidders" - by Che and Gale. The authors describe an isobid curve as the curve that represents payments of the same value in a 2-dimensional plane (wealth and valuation). They state that:

"The isobid curves are negatively sloped and have no interior"

What does it mean that an iso curve has no interior?

**Tags:** microeconomics, mathematical-economics, auctions

---

## 1 answers

### Answer by username_1 on 2017-10-07. Score: 2

From [Wikipedia](https://en.wikipedia.org/wiki/Interior_(topology)):

> In mathematics, specifically in topology, the interior of a subset S of points of a topological space X consists of all points of S that do not belong to the boundary of S. A point that is in the interior of S is an interior point of S. [...] If S is a subset of a Euclidean space, then x is an interior point of S if there exists an open ball centered at x which is completely contained in S. (This is illustrated in the introductory section to this article.)


---

