Models lie at the heart of the emerging model-driven engineering approach. In order to guarantee precise, consistent, and correct models, there is a need for efficient powerful methods for verifying model correctness. Class diagram is the central language within UML. Its correctness problems involve issues of contradiction, namely the consistency problem, and issues of finite instantiation, namely the finite satisfiability problem. This article analyzes the problem of finite satisfiability of class diagrams with class hierarchy constraints and generalization-set constraints. The article introduces the FiniteSat algorithm for efficient detection of finite satisfiability in such class diagrams, and analyzes its limitations in terms of complex hierarchy structures. FiniteSat is strengthened in two directions. First, an algorithm for identification of the cause for a finite satisfiability problem is introduced. Second, a method for propagation of generalization-set constraints in a class diagram is introduced. The propagation method serves as a preprocessing step that improves FiniteSat performance, and helps developers in clarifying intended constraints. These algorithms are implemented in the FiniteSatUSE tool [BGU Modeling Group 2011b], as part of our ongoing effort for constructing a model-level integrated development environment [BGU Modeling Group 2010a].

End-user computing is needed in creative artistic applications or integrated editing environments, where the activity cannot be planned in advance. Following the paper by Orlarey et al., concrete abstractions (abstractions from examples) are suggested as a new mode for function definition, appropriate for end-user editor programmability. For certain applications, the direct, associative, not planned in advance character of concrete abstraction plays a qualitative role in the mere ability to specify abstractions. In this paper, we propose to use concrete abstraction as a general tool for end-user programmability in editors. We distinguish two kinds of abstractions: value abstraction and structure abstraction, and explain how they can be combined. We describe a framework of historical editing that is based on a double view, in which the two abstraction kinds are combined. Finally, BOOMS, an implemented prototype for such an editing framework, is described. BOOMS is a domain-independent toolkit, with three sample instantiations. We believe that the proposed framework captures the conceptualization operation that characterizes creative, associative work types and addresses the needs for end-user computing in integrated environments.

Entity Relationship (ER) schemas include cardinality constraints, that restrict the dependencies among entities within a relationship type. The cardinality constraints have direct impact on application transactions, since insertions or deletions of entities or relationships might affect related entities. Application transactions can be strengthened to preserve the consistency of a database with respect to the cardinality constraints in a schema. Yet, once an ER schema is translated into a logical database schema, the direct correlation between the cardinality constraints and application transaction is lost, since the components of the ER schema might be decomposed among those of the logical database schema. We suggest to extend the Enhanced ER (EER) data model with integrity methods that take the cardinality constraints into account. The integrity methods can be fully defined by the cardinality constraints, using a small number of primitive update methods, and are automatically created for a given EER diagram. A translation of an EER schema into a logical database schema can create integrity routines by translating the primitive update methods alone. These integrity routines may be implemented as database procedures, if a relational DBMS is utilized, or as class methods, if an object-oriented DBMS is utilized.Request access from your librarian to read this article's full text.