The changing world
Robert Kowalski · Cambridge University Press eBooks · 2011
In mathematics, semantic structures are static and truth is eternal. But for an intelligent agent embedded in the real world, semantic structures are dynamic and the only constant is change. Perhaps the simplest way to understand change is to view actions and other events as causing a change of state from one static world structure to the next. For example:This view of change is formalised in the possible world semantics of modal logic. In modal logic , sentences are given a truth value relative to a static possible world embedded in a collection of possible worlds linked with one another by an accessibility relation.