On fuzzy arithmetic for discrete fuzzy numbers

On discrete fuzzy number space, the usual addition and multiplication does not keep the closeness of operation. This brings about some inconveniences in its applications. Recently, we give two kinds of operations of addition and multiplication for discrete fuzzy numbers, which keep the closeness of the operation, so they get over the defect of the usual addition and multiplication. In this paper, in order to make operations of addition and multiplication to more accord with the actual meaning, we again give some new kinds of operations of addition and multiplication for discrete fuzzy numbers. Then, we show that the new additions and multiplications keep the closeness of the operation, so they not only more fit the essential of the operations, but also get over the defect that the usual addition and multiplication does not keep the closeness of operation. And we also point out that when the usual addition of two discrete fuzzy numbers is still a discrete fuzzy number, the usual addition and the new additions are identical, and so are the usual multiplication and the new multiplications.