Closed Formulas
A closed formula, also ground formula or sentence, is a formula in which there are no free occurrences of any variable. If A is a formula of a first-order language in which the variables v1, ..., vn have free occurrences, then A preceded by v1 ... vn is a closure of A.
Read more about this topic: Well-formed Formula
Famous quotes containing the words closed and/or formulas:
“We are closed in, and the key is turned
On our uncertainty;”
—William Butler Yeats (1865–1939)
“You treat world history as a mathematician does mathematics, in which nothing but laws and formulas exist, no reality, no good and evil, no time, no yesterday, no tomorrow, nothing but an eternal, shallow, mathematical present.”
—Hermann Hesse (1877–1962)