Fuzzy Programming: Why and How? — Some Hints and Examples

The procedures used by the human mind to manipulate data are not often precisely specified. This situation is not generally due to an intrinsic imprecision of the natural language we used: in English or French, for instance, we are certainly able to express things in a precise way most of the time. It is not generally for the pleasure that people may be imprecise or vague in stating facts or methods, although some of them take advantage of it when they want to hide something! It is not even due to some intrinsic inability of the mind to put things into words. The deep reason of possible imprecision in specifying seems to be elsewhere. Sometimes precise data are simply not available because we have not the tools to perform precise measures or because it is impossible to do it: the processing time of an operation which has not been performed yet can be only evaluated on the basis of our a priori knowledge: this evaluation is more or less precise according to the situations; we have a possibility distribution concerning the value of the processing time. When the information is stored in our memory, we may be somewhat uncertain if we try to remember too precise facts.