We study the second bounded cohomology of an amalgamated free product of groups, and an HNN extension of a group. As an application, we have a group with infinitely many ends has infinite dimensional second bounded cohomology.

When combining languages for symbolic constraints, one is typically faced with the problem of how to treat \mixed" constraints. The two main problems are (1) how to deene a combined solution structure over which these constraints are to be solved, and (2) how to combine the constraint solving methods for pure constraints into one for mixed constraints. The paper introduces the notion of a \free...

The theory of algebraic graph transformation has proven to be a suitable underlying formal framework to reason about the behavior of model transformations. In order to model an arbitrary number of actions at different places in the same model, the concept of amalgamated graph transformation has been proposed. Rule applications of certain regularity are described by a rule scheme which contains ...