Polish Spaces
Descriptive set theory begins with the study of Polish spaces and their Borel sets.
A Polish space is a second countable topological space that is metrizable with a complete metric. Equivalently, it is a complete separable metric space whose metric has been "forgotten". Examples include the real line, the Baire space, the Cantor space, and the Hilbert cube .
Read more about this topic: Descriptive Set Theory
Famous quotes containing the words polish and/or spaces:
“‘Then I polish all the silver, which a supper-table lacquers;
Then I write the pretty mottoes which you find inside the
crackers’—”
—Sir William Schwenck Gilbert (1836–1911)
“Le silence éternel de ces espaces infinis m’effraie. The eternal silence of these infinite spaces frightens me.”
—Blaise Pascal (1623–1662)