Units of paper quantity Units of paper quantity Various measures of paper quantity have been and are in use. Although there are no S.I. units such as quires and bales, there are ISO and DIN standards for the ream. Expressions used here include U.S. Customary units. A quire of paper is a measure of paper quantity. The usual meaning is 25 sheets of the same size and quality: of a ream of 500 sheets. Quires of 25 sheets are often used for machine-made paper, while quires of 24 sheets are often used for handmade or specialised paper of 480-sheet reams. (As an old UK
Many-one reduction problem is easy to solve. The many-one reduction is more effective at separating problems into distinct complexity classes. However, the increased restrictions on many-one reductions make them more difficult to find. Many-one reductions were first used by Emil Post in a paper published in 1944. Later Norman Shapiro used the same concept in 1956 under the name "strong reducibility". Suppose "A" and "B" are formal languages over the alphabets Σ and Γ, respectively. A many-one reduction from "A" to "B" is a total computable function "f" : Σ → Γ that has the property that each word "w" is in