Web Services composition - from ontology to plan by query

The paper proposes a method to cover the world of web services with a uniform semantics, possibly simple but enabling to arrange complex flows of service invocations. The flows are built according to fully declarative user's intentions, specified in a language common for the descriptions of services and for the query. In the approach we model the world of services and of the subjects they operate on using a uniform knowledge database and an objectoriented manner. The current work describes the first phase of the composition: making an abstract plan, i.e., giving an answer how (with what types of services) the required effect can be obtained. The problem of creating a plan is converted to building a specialized graph.