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:
“No domain of nature is quite closed to man at all times.”
—Henry David Thoreau (1817–1862)
“That’s the great danger of sectarian opinions, they always accept the formulas of past events as useful for the measurement of future events and they never are, if you have high standards of accuracy.”
—John Dos Passos (1896–1970)