Abstract-- Pervasive Computing refers to a seamless and invisible computing environment which provides dynamic, proactive and context-aware services to the user by acquiring context knowledge from the environment and composing available services. In this paper, we demonstrate how heterogeneous Web services can be made interoperable and used to support Pervasive Computing. We present an architecture how a service flow can be automatically composed using syntactic, semantic and pragmatic knowledge. Thus, this paper addresses three problems: (1) How do heterogeneous Pervasive Computing services interoperate in a Pervasive Computing service flow, composed by using syntactic, semantic and pragmatic knowledge; (2) How do we define, distinguish between, and justify the need for these three different kinds of knowledge to be used in service descriptions; and (3) How can we perform ontology integration to enable the automatic composition of Web services into a service flow. A Pervasive Computin...