Scientific data of importance to biologists in the Human Genome Project resides not only in conventional databases, but in structured files maintained in a number of different formats (e.g. ASN.1 and ACE) as well as sequence analysis packages (e.g. BLAST and FASTA). These formats and packages contain a number of data types not found in conventional databases, such as lists and variants, and may be deeply nested. We present in this paper techniques for querying and transforming such data, and illustrate their use in a prototype system developed in conjunction with the Human Genome Center for Chromosome 22. We also describe optimizations performed by the system, a crucial issue for bulk data. 1 Introduction The goal of the Human Genome Project (HGP) is to sequence the 24 distinct chromosomes comprising the human genome. Much of the information associated with the HGP resides not in conventional databases, but in files that have been formatted according to a variety of conventions. These...

Machine" [BB90], except that there are no "cooling" and "heating" transitions (the process sets of this semantics can be thought of as perpetually "hot" solutions). The concurrent evaluation relation extends "7\Gamma!" to finite sets of terms (i.e., processes) and adds additional rules for process creation, channel creation, and communication. We assume a set of process identifiers, and define the set of processes and process sets as: ß 2 ProcId process IDs p = hß; ei 2 Proc = (ProcId \Theta Exp) processes P 2 Fin(Proc) process sets We often write a process as hß; E[e]i, where the evaluation context serves the role of the program counter, marking the current state of evaluation. Definition4. A process set P is well-formed if for all hß; ei 2 P the following hold: -- FV(e) = ; (e is closed), and -- there is no e 0 6= e, such that hß; e 0 i 2 P. It is occasionally useful to view well-formed process sets as finite maps from ProcId to Exp. If P is a finite set of process state...

. A monad for concurrent programming that is suitable for being built into Haskell is presented. The monad consists of only four primitives with a very simple semantics. A number of examples demonstrate that monads encapsulating other, more sophisticated communication paradigms known from concurrent functional languages such as Concurrent ML, Facile, and Erlang can be naturally and systematically constructed from the built-in monad in a purely functional way. The paper argues that minimizing the number and complexity of the concurrency primitives and maximizing the use of purely functional abstractions in the design of concurrent languages helps to remedy a recurrent dilemma, namely, how to keep the language small and rigorously defined, yet to provide the programmer with all the communication constructs required. An interleaving implementation of the monad has been built by extending Mark Jones's Gofer environment to handle the concurrency primitives. All programs presented ...

this report, the focus is on the optimizer of the Kleisli/CPL system. As mentioned earlier, the system is being applied to query heterogeneous biological data sources. This application environment has the following characteristics.

A "future" is a typed synchronization mechanism used to represent avalue that will come into existence at some point in time after the creation of the future. In this paper, a polymorphic future type is introduced that differs from previous mechanisms in that it provides a first-class, extensible facility for expressing synchronized access to the typed result value of a concurrent computation. The proposed mechanism requires write-once/read-many synchronization, which is implemented in terms of common thread synchronization primitives, thereby ensuring a high-degree of efficiency. The type definition and type specialization features of C++ are used to illustrate how one would implement a polymorphic future type in a strongly typed object-oriented language supporting polymorphic type definitions.

A procedure for systematic design of event based systems is introduced by means of the Production Cell case study. The design is documented by CSP-style processes, which allow both verification using formal techniques and also validation of a rapid prototype in the functionallanguage CML. 1. Introduction Notations like CSP [1] or CCS [2] provide concise notations for documenting the design of reactive or real-time systems. These notations further allow verification of properties through calculation, or model checking [3]. Yet there is a sizable gap from such specifications to executable programs needed to validate or test the design [4, 5, 6, 7]. In this paper we demonstrate how this gap is closed by CML [8], an extension of ML [9]. As shown in this paper, it is easy to get from a CSP design to an executable CML program, and the program can be interfaced to programs in other programming languages. We illustrate this idea by applying the design method for real-time systems presented in...

Abstract. In this paper, we present a formal verification framework for higherorder value-passing process algebra. This framework stems from an established synergy between type inference and model-checking. The language considered here is based on a sugared version of an implicitly typed λ-calculus extended with higher-order synchronous concurrency primitives. First, we endow such a syntax with a semantic theory made of a static semantics together with a dynamic semantics. The static semantics consists of an annotated type system. The dynamic semantics is operational and comes as a two-layered labeled transition system. The dynamic semantics is abstracted into a transitional semantics so as to make finite some infinite-state processes. We describe the syntax and the semantics of a verification logic that allows one to specify properties. The logic is an extension of the modal µ-calculus for handling higher-order processes, value-passing and return of results. 1

This document describes the eXene widget library; it is a companion to The eXene Library Manual [RG93], which is also included in the distribution.

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