Cy Williams, thirteen, has always known that he and the other black folks on Strong's plantation have to obey white men, no question. Sure, he's free, as black people have been since his grandfather's day, but in rural Georgia, that means they're free to be whipped, abused, even killed. Almost four years later, Cy yearns for that freedom, such as it was. Now he's a chain gang laborer, forced to do backbreaking work, penned in and shackled like an animal, brutalized, beaten, and humiliated bythe boss of the camp and his hired overseers. For Cy and the boys he's chained to, there's no way out, no way back. And then hope begins to grow in him, along with strength and courage he didn't know he had. Cy is sure that a chance at freedom is worth any risk, any sacrifice. This powerful, moving story opens a window on a painful chapter in the history of race relations.

Cy Williams, thirteen, has always known that he and the other black folks on Strong's plantation have to obey white men, no question. Sure, he's free, as black people have been since his grandfather's day, but in rural Georgia, that means they're free to be whipped, abused, even killed. Almost four years later, Cy yearns for that freedom, such as it was. Now he's a chain gang laborer, forced to do backbreaking work, penned in and shackled like an animal, brutalized, beaten, and humiliated by the boss of the camp and his hired overseers. For Cy and the boys he's chained to, there's no way out, no way back. And then hope begins to grow in him, along with strength and courage he didn't know he had. Cy is sure that a chance at freedom is worth any risk, any sacrifice. This powerful, moving story opens a window on a painful chapter in the history of race relations.

This book presents an English translation of a classic Russian text on duality theory for Heyting algebras. Written by Georgian mathematician Leo Esakia, the text proved popular among Russian-speaking logicians. This translation helps make the ideas accessible to a wider audience and pays tribute to an influential mind in mathematical logic. The book discusses the theory of Heyting algebras and closure algebras, as well as the corresponding intuitionistic and modal logics. The author introduces the key notion of a hybrid that “crossbreeds” topology (Stone spaces) and order (Kripke frames), resulting in the structures now known as Esakia spaces. The main theorems include a duality between the categories of closure algebras and of hybrids, and a duality between the categories of Heyting algebras and of so-called strict hybrids. Esakia’s book was originally published in 1985. It was the first of a planned two-volume monograph on Heyting algebras. But after the collapse of the Soviet Union, the publishing house closed and the project died with it. Fortunately, this important work now lives on in this accessible translation. The Appendix of the book discusses the planned contents of the lost second volume.

This work is an introduction to the basic tools of the theory of (partially) ordered sets such as visualization via diagrams, subsets, homomorphisms, important order-theoretical constructions, and classes of ordered sets. Using a thematic approach, the author presents open or recently solved problems to motivate the development of constructions and investigations for new classes of ordered sets. A wide range of material is presented, from classical results such as Dilworth's, Szpilrajn's and Hashimoto's Theorems to more recent results such as the Li--Milner Structure Theorem. Major topics covered include: chains and antichains, lowest upper and greatest lower bounds, retractions, lattices, the dimension of ordered sets, interval orders, lexicographic sums, products, enumeration, algorithmic approaches and the role of algebraic topology. Since there are few prerequisites, the text can be used as a focused follow-up or companion to a first proof (set theory and relations) or graph theory class. After working through a comparatively lean core, the reader can choose from a diverse range of topics such as structure theory, enumeration or algorithmic aspects. Also presented are some key topics less customary to discrete mathematics/graph theory, including a concise introduction to homology for graphs, and the presentation of forward checking as a more efficient alternative to the standard backtracking algorithm. The coverage throughout provides a solid foundation upon which research can be started by a mathematically mature reader. Rich in exercises, illustrations, and open problems, Ordered Sets: An Introduction is an excellent text for undergraduate and graduate students and a good resource for the interested researcher. Readers will discover order theory's role in discrete mathematics as a supplier of ideas as well as an attractive source of applications.

If an entire nation could seek its freedom, why not a girl? As the Revolutionary War begins, thirteen-year-old Isabel wages her own fight...for freedom. Promised freedom upon the death of their owner, she and her sister, Ruth, in a cruel twist of fate become the property of a malicious New York City couple, the Locktons, who have no sympathy for the American Revolution and even less for Ruth and Isabel. When Isabel meets Curzon, a slave with ties to the Patriots, he encourages her to spy on her owners, who know details of British plans for invasion. She is reluctant at first, but when the unthinkable happens to Ruth, Isabel realizes her loyalty is available to the bidder who can provide her with freedom. From acclaimed author Laurie Halse Anderson comes this compelling, impeccably researched novel that shows the lengths we can go to cast off our chains, both physical and spiritual.

Over the past 40 years, RIS models for hundreds of polymer structures have been developed, and now the RIS approach is available in several software packages. However, users are often faced with the time-consuming task of finding the appropriate RIS parameters among the literature. This book facilitates this task by providing a comprehensive overview of the models available. It reviews the literature from the very first applications to the end of 1994, comprises synthetic as well as naturally occuring macromolecules, and tabulates all the pertinent features of published models. It will thus help readers, even those new to this method, to take advantage of this computationally efficient way of assessing the conformational properties of macromolecular systems.

This book contains twenty-two papers presented at the International Conference in Combinatorics, held in Jerusalem in May 1993. The papers describe some of the latest developments in algebraic combinatorics, enumeration, graph and hypergraph theory, combinatorial geometry, and geometry of polytopes and arrangements. The papers are accessible to specialists as well as nonspecialists.