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:
“You will have to polish up the stars
with Bab-o and find a new God
as the earth empties out
into the gnarled hands of the old redeemer.”
—Anne Sexton (1928–1974)
“Every true man is a cause, a country, and an age; requires infinite spaces and numbers and time fully to accomplish his design;—and posterity seem to follow his steps as a train of clients.”
—Ralph Waldo Emerson (1803–1882)