Think of a sequence of dots on a plane (or line). Let's suppose that they have the following property:

In effect, we are asking that the points approach a limit. The reason for stating it as we have is because the limit point might not be in the set itself.
Such a sequence is called a Cauchy Sequence.

Here are some examples on a line:

Here are some sequences that are not Cauchy Sequences:

Cauchy sequences are a method used to construct the real numbers from the rational numbers.
Last change to this page
Full Page history
Links to this page
Edit this page
  (with sufficient authority)
Change password
Recent changes
All pages
Search