The objective of this study was to evaluate the morphometric and reproductive traits of indigenous dairy goat types. It was conducted in three districts (Ebnat, Gonji-kolela and Farta) based on the agro-ecological differences, goat population potentials and experience of the farmers using goat milk. Semi-structured questionnaires, field observations, morphological and reproductive trait measure...

Cryptographic types are a way to express cryptographic guarantees (of secrecy and integrity) in a type system for a network programming language. This allows some of these guarantees to be checked statically, before a network program executes. Where dynamic checks are required, these are represented at the source language level as dynamic type-checking, and are translated by the compiler to low...

System L is a linear λ-calculus with numbers and an iterator, which, although imposing linearity restrictions on terms, has all the computational power of Gödel’s System T . System L owes its power to two features: the use of a closed reduction strategy (which permits the construction of an iterator on an open function, but only iterates the function after it becomes closed), and the use of a l...

Vladimir Gapeyev Michael Y. Levin Benjamin C. Pierce Department of Computer and Information Science University of Pennsylvania fvgapeyev,bcpierce,[email protected] Category: Pearls Abstract Algorithms for checking subtyping between recursive types lie at the core of many modern programming language implementations. But the fundamental theory of these algorithms and how they relate to simpl...

Phantom types are data types with type constraints associated with different cases. Examples of phantom types include typed type representations and typed higher-order abstract syntax trees. These types can be used to support typed generic functions, dynamic typing, and staged compilation in higher-order, statically typed languages such as Haskell or Standard ML. In our system, type constraints...

We currently see a convergence of module systems and type systems for object-oriented programming. This convergence is driven by the demands of large scale component systems. Objectoriented languages for medium-scale systems such as Eiffel or Sather still worked with an unstructured set of classes, but as systems grow this becomes less practical. Consequently, more recent languages such as Beta...

Pedigree Types are an intuitive ownership type system requiring minimal programmer annotations. Reusing the vocabulary of human genealogy, Pedigree Types programmers can qualify any object reference with a pedigree – a child, sibling, parent, grandparent, etc – to indicate what relationship the object being referred to has with the referant on the standard ownership tree, following the owners-a...

For an arbitrary simplicial complex K, Davis and Januszkiewicz have defined a family of homotopy equivalent CW-complexes whose integral cohomology rings are isomorphic to the Stanley-Reisner algebra of K. Subsequently, Buchstaber and Panov gave an alternative construction, which they showed to be homotopy equivalent to Davis and Januszkiewicz’s examples. It is therefore natural to investigate t...

We are interested in the class of systems for which the satisfaction of code dependencies is a dynamic process rather than one which is determined purely at load-time. Examples include dynamic delegation, mobile code and agent systems. Such systems exhibit properties which are not well-captured by current typing models. We describe a system of ionic object types which capture these effects and ...