Problem SolvingAn approach to supporting work in the office is described.Using and extending ideas from the field of artificial intelligence (AI) we describe office work as a problem-solving activity.A knowledgeembedding language called OMEGA is used to embed knowledge of the organization into an office worker's work station in order to support the office worker in problem solving.A particular approach to reasoning about change and contradiction is discussed.This approach uses OMEGA's viewpoint mechanism, which is a general contradiction-handling facility.Unlike other knowledge representation systems, when a contradiction is reached the reasons for the contradiction can be analyzed by the deduction mechanism without having to resort to search mechanisms such as a backtracking.The viewpoint mechanism is the heart of the problem-solving support paradigm, a paradigm which supplements the classical AI view of problem solving.An example is presented in which OMEGA's facilities are used to support an office worker's problem-solving activities.The example illustrates the use of viewpoints and of OMEGA's capabilities to reason about its own reasoning processes.