Closed Unbounded Class

Famous quotes containing the words closed and/or class:

“We are closed in, and the key is turned
On our uncertainty;”
—William Butler Yeats (1865–1939)

“It is the mark of an educated man to look for precision in each class of things just so far as the nature of the subject admits; it is evidently equally foolish to accept probable reasoning from a mathematician and to demand from a rhetorician demonstrative proofs.”
—Aristotle (384–323 B.C.)