UMLR — UML Support for multiple library levels

In large-scale development environments where development may be iterative and/or incremental, it often happens that there are standardized libraries of common or reusable elements, in various levels of completion. These may be type definitions, classes, objects, parts, requirements, etc. While current «import» and «access» are useful to reuse these elements, we need the ability to specify an ordered chain of libraries, where an element usage would obtain the first occurrence of the element in the chain. Note that the libraries may be located remotely or on the web.