Formal Definition
A decision problem can be associated with a language, where the problem is to accept all inputs in and reject all inputs not in . For a promise problem, there are two languages, and, which must be disjoint, which means, such that all the inputs in are to be accepted and all inputs in are to be rejected. The set is called the promise. There are no requirements on the output if the input does not belong to the promise. If the promise equals, then this is also a decision problem, and the promise is said to be trivial.
Read more about this topic: Promise Problem
Famous quotes containing the words formal and/or definition:
“The bed is now as public as the dinner table and governed by the same rules of formal confrontation.”
—Angela Carter (1940–1992)
“Mothers often are too easily intimidated by their children’s negative reactions...When the child cries or is unhappy, the mother reads this as meaning that she is a failure. This is why it is so important for a mother to know...that the process of growing up involves by definition things that her child is not going to like. Her job is not to create a bed of roses, but to help him learn how to pick his way through the thorns.”
—Elaine Heffner (20th century)