Complete Metric Space

Complete Metric Space

In mathematical analysis, a metric space M is called complete (or a Cauchy space) if every Cauchy sequence of points in M has a limit that is also in M or, alternatively, if every Cauchy sequence in M converges in M.

Intuitively, a space is complete if there are no "points missing" from it (inside or at the boundary). For instance, the set of rational numbers is not complete, because e.g. is "missing" from it, even though one can construct a Cauchy sequence of rational numbers that converges to it. (See the examples below.) It is always possible to "fill all the holes", leading to the completion of a given space, as explained below.

Read more about Complete Metric Space:  Examples, Some Theorems, Completion, Topologically Complete Spaces, Alternatives and Generalizations

Famous quotes containing the words complete and/or space:

    “The Good of man is the active exercise of his soul’s faculties in conformity with excellence or virtue.... Moreover this activity must occupy a complete lifetime; for one swallow does not make spring, nor does one fine day; and similarly one day or a brief period of happiness does not make a man supremely blessed and happy.”
    —Aristotle (384–322 B.C.)

    “Why not a space flower? Why do we always expect metal ships?”
    —W.D. Richter (b. 1945)