Carnivorous Caterpillars

Universal caterpillars

For a class V of graphs, denote by a(@?) the least value of m so that for some graph II on m vertices, every GE Q occurs as a subgraph of U. In this note we obtain rather sharp bounds on u(q) when Q is the class of caterpillars on n vertices, i.e., tree with property that the vertices of degree exceeding one induce a path. Recently several of the authors have investigated graphs U(g) which are ...

Carnivorous plants

Figure 1. Carnivorous plants. When we chew and then swallow meat, we stimulate glands (pancreatic acinar cells) to secrete hydrochloric acid and proteases. Amino acids released into the human stomach by the acidic lytic sap are forwarded to and taken up by the intestine. When compared with the human endocrine system, the Venus flytrap also operates as a mouth, stomach and intestine, all combine...

Looping Caterpillars

There are two main paradigms for querying semi structured data: regular path queries and XPath. The aim of this paper is to provide a synthesis between these two. This synthesis is given by a small addition to tree walk automata and the corresponding caterpillar expressions. These are evaluated on unranked finite sibling-ordered trees. At the expression level we add an operator whose meaning is...

Rollercoasters and Caterpillars

A rollercoaster is a sequence of real numbers for which every maximal contiguous subsequence, that is increasing or decreasing, has length at least three. By translating this sequence to a set of points in the plane, a rollercoaster can be defined as a polygonal path for which every maximal sub-path, with positiveor negative-slope edges, has at least three points. Given a sequence of distinct r...

Caterpillars and polymorphisms.