We investigate the descriptional complexity of limited propagating Lindenmayer systems and their deterministic and tabled variants with respect to the number of rules and the number of symbols. We determine the decrease of complexity when the generative capacity is increased. For incomparable families, we give languages that can be described more efficiently in either of these families than in ...

In this paper we study the properties of systems of bounded arithmetic capturing small complexity classes and state conditions sufficient for such systems to capture the corresponding complexity class tightly. Our class of systems of bounded arithmetic is the class of secondorder systems with comprehension axiom for a syntactically restricted class of formulas Φ ⊂ Σ 1 based on a logic in the de...

We describe our development and use of DescriptiveEnvironment (DE). This is a program to aid researchers in Finite Model Theory and students of logic to automatically generate examples, counterexamples of conjectures, reductions between problems, and visualizations of structures and queries. DescriptiveEnvironment is available for free use under an ISC license at http://www.cs.umass.edu/∼immerm...

Leadership Studies is a new interdisciplinary field of Organization Studies that is growing at a steady rate all over the world. Leadership studies are seen as a branch of Management and Organization Sciences despite its philosophical roots that can be traced back to Plato’s philosophical writings such as Laws, Politics, or The Republic. Starting from Burns’ seminal book, Leadership (1978), and...

In Chapter 1, we introduce a notion of universality for subgroups of Polish groups that has both algebraic and topological aspects. More precisely, given a class C of subgroups of a topological group Γ, we say that a subgroup H ∈ C is a universal C subgroup of Γ if every subgroup K ∈ C is a continuous homomorphic preimage of H. Such subgroups may be regarded as complete members of C with respec...

The purpose of this paper is to outline some recent progress in descriptive inner model theory, a branch of set theory which studies descriptive set theoretic and inner model theoretic objects using tools from both areas. There are several interlaced problems that lie on the border of these two areas of set theory, but one that has been rather central for almost two decades is the conjecture kn...

Definition 1.1. Let (X, τ) be a topological space. A subset D ⊆ X is called dense if D ∩O 6= ∅ for every nonempty open set O ⊆ X. X is called separable if X has a countable dense subset. X is called metrizable if there is a metric d on X such that the topology τ is the same as the topology induced by the metric. The metric is called complete if every Cauchy sequence converges in X. Finally, X i...