A theory of retractable and speculative contracts

International audienceBehavioral contracts are abstract descriptions of expected communication patterns followed by either clients or servers during their interaction. Behavioral contracts come naturally equipped with a notion of compliance: when a client and a server follow compliant contracts, their interaction is guaranteed to progress or successfully complete. We study two extensions of behavioral contracts, retractable contracts dealing with backtracking and speculative contracts dealing with speculative execution. We show that the two extensions give rise to the same notion of compliance. As a consequence, they also give rise to the same subcontract relation, which determines when one server can be replaced by another preserving compliance. Moreover, compliance and subcontract relation are both decidable in quadratic time. Finally, we study the relationship between retractable contracts and calculi for reversible computing

Judicial Capacities and Patent Claim Construction: An Ordinary Reader Standard

Patent claim construction is a mess. The Federal Circuit’s failure to provide adequate guidance has created significant problems for the patent system. The problems with claim construction result from the Federal Circuit’s inability to resolve whether claim terms should be given (1) the general, acontextual meaning they would have to a skilled person in the field; (2) the specific meaning they have in the context of the patent; or (3) some combination of the two. The claim construction debate largely overlooks the generalist judges who must implement claim construction. This Article fills that gap, concluding that existing approaches are difficult, costly, and error prone for generalist judges because they force the judge to step into the shoes of a scientist. It is time to abandon the legal fiction that claims should be construed from the perspective of a skilled person in the field—instead, judges should construe claims from the perspective of an ordinary reader discerning meaning from the context of the patent. The ordinary reader standard is more familiar to generalist judges, easier and cheaper to apply, and less error prone. Perhaps surprisingly, it is also consistent with the nature of claim construction. Rather than eliminate technical context, an ordinary reader standard focuses on the technical context that was provided by the patentee, is publicly available to everyone, and by definition reflects the skill level, field, and time of the invention. And,rather than ignore the audience for patent claims, it provides a common ground for the varied consumers of modern patent claims: skilled people, business people, patent examiners, lawyers, and judges

Transformative Architecture Through Kinetic Mechanisms

This thesis started with an interest in transformable architecture which will allow it to become adaptive. Zuk and Clark, in “Kinetic Architecture,” argued that modern architecture was outdated because of its static nature. Architecture can address these challenges in a simple and intentional manner if kinetics are included. This removes demolition and expensive remodeling. Plants and animals adapt kinetically, such as growing cells in the opposite direction in which they were bent, sets of muscles that flex and extend to kinetically move a limb, or transforming its whole body and positioning each limb strategically to maximize the range of movement and minimize the effort. All of these concepts are applicable in architecture. The research started with various mechanisms that enable movement; from joints in hinges or folding mechanisms, to pivoting systems that revolve around a defined axis, to sliding and telescopic mechanisms that allow elements to be displaced along a defined path. I developed a taxonomy of to organize these kinetic examples. The categories include mechanism (sliding, telescopic, pivoting-rotating, hinging-folding, and pneumatic structures), transformations of geometry (scale, change of volume, addition-subtraction, and deformation), architectural elements (point, line, plane, and volume), direction of movement (horizontal, vertical, diagonal, and axial), energy input (human, hydraulic, mechanical, and chemical), transformations of space enclosure, open, hybrid), and physical components(partition, roof, floor, and structure). This thesis raised the following questions: What are the architectural design principles that can be applied to create spatial experiences? How are these principles incorporated into kinetic architecture? How can we create multiple spatial experiences based on the possibility to change space? In what situations is transformable architecture more convenient than conventional static architecture? These questions are explored in a series of studies that led to the conceptual design of a collapsible skyscraper

The Goals of Contract Remedies

This article offers a general account of the rules that regulate exit and loyalty in contract disputes to make some fundamental points about the goals of contract remedies. The dominant goal of these rules, like all of contract remedies, is vindicating contracting rights. When contract rights give way it is almost always for one of two reasons. Rights sometimes give way to advance the goal of efficient performance. This goal is familiarly expressed by the mitigation principle and, in American contract law, by the theory of efficient breach. Rights also give way to advance the goal of remedial simplicity. In a nutshell, the rules that regulate exit and loyalty in contract disputes, like all of contract remedies, vindicate contract rights at the least cost and with the least fuss. This should be utterly unsurprising. More interesting are the trade offs made when these goals conflict. A contract right’s certainty is of crucial significance. I define a contract right as certain when the right to a performance from another is indisputable. There is an important distinction between the right to a performance and the worth of that performance to the right-holder. Often the right a performance is certain while its worth to the right-holder is uncertain. When a contract right is certain or indisputable contract law permits a right-holder to take a self-help measure, such as exiting from a contract, to avoid suffering an uncompensated loss even though the measure inflicts a disproportionate loss on the defaulter. In other words, the goal of vindicating rights trumps the goal of efficient performance when it comes to self-help remedies that do not unduly tax courts. More bluntly, the theory of efficient breach is bunk as a descriptive matter when it comes to the rules that regulate self-help responses to an indisputable default. The goal of efficient performance drives other aspects of contract remedies. Trivially, the mitigation doctrine and other rules compel a party to vindicate a right in the cheapest way possible. More interestingly, the goal of efficient performance explains the law’s response to loyalty in the face of contract uncertainty. By this I mean when a party performs a disputed obligation or accepts performance of disputed adequacy. I show that performance of a disputed obligation (or acceptance of performance of disputed adequacy) does not preclude the later assertion of a claim of a lesser obligation (or of a greater right), but only if performance (or acceptance of performance) avoids a loss. This point, which I believe is novel but seems obvious once you think about it, systematizes what now is a very tangled thicket of law. There is scant authority on the related question whether contract uncertainty warrants withholding or refusing performance. I think this is because courts have not had to confront the question directly. It tended not to arise under traditional common law rules, which made contract rights and obligations certain or unenforceable. This is changing. I highlight a fascinating decision by Judge Posner that confronts the question and answers that contract uncertainty does warrant exit, indeed his reasoning suggests uncertainty may require exit. Judge Posner is on to something important. However, putting the issue in a broader frame shows that the power to exit from an uncertain contract is cosseted by other rules that discourage exit when it would result in a consequential loss