Summary: In this note we define the concept of approximate truth, and outline the corresponding logic, called the rough (approximate) logic, in short R- logic. The starting point of our considerations is the notion of a rough set introduced by the author earlier, as mathematical tool to deal with the imprecise information.
The concept of approximate truth has called attention of many researchers in philosophy, logic and recently in computer science. The latest were mainly motivated by artificial intelligence research in expert system, approximate reasoning methods and others.
The aim of this note is to provide a theoretical framework to this kind of problems, where truth is not known exactly but only with a certain approximation.