Deletion operations: closure properties

Deletion operations: closure properties.dvi

The paper studies some variants of deletion operations which generalize the left/right quotient of languages. The main emphasis is put on how these deletions can be expressed as a combination of other operations, and on closure properties of various language families under deletion. Some results are the expected ones: the sequential (iterated sequential, dipolar) deletion from a regular languag...

Closure operations in phylogenetics.

Closure operations are a useful device in both the theory and practice of tree reconstruction in biology and other areas of classification. These operations take a collection of trees (rooted or unrooted) that classify overlapping sets of objects at their leaves, and infer further tree-like relationships. In this paper we investigate closure operations on phylogenetic trees; both rooted and unr...

Closure Systems and Closure Operations in Dedekind

The concepts of closure systems and closure operations in lattice theory are basic and applied to many fields in mathematics and theoretical computer science. In this paper authors find out a suitable definition of closure systems in Dedekind categories, and thereby give an equivalence proof for closure systems and closure operations in Dedekind categories.

Insertion operations: closure properties.dvi

The basic notions used for specifying languages are of algorithmic or operational character: automata (accepting devices) or grammars (generating devices). This duality reflects the original motivations coming from computer science or linguistics. A deeper theory and more involved proofs called for alternative definitional devices, where the operations have a classical mathematical character. E...

Closure, Properties and Closure Properties of Multirelations