When to filter what, or prediction isn´t explanation

Discusses the minimal entailment relation proposed by E. Sandewall (1989). It is argued that Sandewall´s notion of entailment is well suited for prediction but is incapable of accounting for evidence contradicting the predicted `normal´ course of events. The author does not describe a complete solution to this problem. However it is suggested that a solution has to be based on distinguishing between different purposes of the reasoning process, such as prediction or explanation. A problem solver must then make the assumptions underlying a particular mode of reasoning explicit in order to be able to reason about them and to retract them in the light of conflicting evidence. Sandewall´s combination of logic and differential equations and its relevance to the area of intelligent control are described. The minimal entailment relation is introduced, and a problem with the logic when it comes to multiple modes of reasoning is presented. A solution based on mode assumptions is suggested