91,360 research outputs found
Contract agreements via logic
We relate two contract models: one based on event structures and game theory,
and the other one based on logic. In particular, we show that the notions of
agreement and winning strategies in the game-theoretic model are related to
that of provability in the logical model.Comment: In Proceedings ICE 2013, arXiv:1310.401
Contracts in distributed systems
We present a parametric calculus for contract-based computing in distributed
systems. By abstracting from the actual contract language, our calculus
generalises both the contracts-as-processes and contracts-as-formulae
paradigms. The calculus features primitives for advertising contracts, for
reaching agreements, and for querying the fulfilment of contracts. Coordination
among principals happens via multi-party sessions, which are created once
agreements are reached. We present two instances of our calculus, by modelling
contracts as (i) processes in a variant of CCS, and (ii) as formulae in a
logic. With the help of a few examples, we discuss the primitives of our
calculus, as well as some possible variants.Comment: In Proceedings ICE 2011, arXiv:1108.014
Knowledge Representation Concepts for Automated SLA Management
Outsourcing of complex IT infrastructure to IT service providers has
increased substantially during the past years. IT service providers must be
able to fulfil their service-quality commitments based upon predefined Service
Level Agreements (SLAs) with the service customer. They need to manage, execute
and maintain thousands of SLAs for different customers and different types of
services, which needs new levels of flexibility and automation not available
with the current technology. The complexity of contractual logic in SLAs
requires new forms of knowledge representation to automatically draw inferences
and execute contractual agreements. A logic-based approach provides several
advantages including automated rule chaining allowing for compact knowledge
representation as well as flexibility to adapt to rapidly changing business
requirements. We suggest adequate logical formalisms for representation and
enforcement of SLA rules and describe a proof-of-concept implementation. The
article describes selected formalisms of the ContractLog KR and their adequacy
for automated SLA management and presents results of experiments to demonstrate
flexibility and scalability of the approach.Comment: Paschke, A. and Bichler, M.: Knowledge Representation Concepts for
Automated SLA Management, Int. Journal of Decision Support Systems (DSS),
submitted 19th March 200
Contract-Oriented Computing in CO2
We present CO2, a parametric calculus for contract-based computing in distributed systems. By abstracting from the actual contract language, our calculus generalises both the contracts-as-processes and contracts-as-formulae paradigms. The calculus features primitives for advertising contracts, for reaching agreements, and for querying the fulfilment of contracts. Coordination among participants happens via multi-party sessions, which are created once agreements are reached. We present two instances of our calculus, by modelling contracts as processes in a variant of CCS, and as formulae in a logic. We formally relate the two paradigms, through an encoding from contracts-as-formulae to contracts-as-processes which ensures that the promises deducible in the logical system are exactly those reachable by its encoding as a process. Finally, we present a coarse-grained taxonomy of possible misbehaviours in contract-oriented systems, and we illustrate them with the help of a variety of examples
Temporal Aspects of Smart Contracts for Financial Derivatives
Implementing smart contracts to automate the performance of high-value
over-the-counter (OTC) financial derivatives is a formidable challenge. Due to
the regulatory framework and the scale of financial risk if a contract were to
go wrong, the performance of these contracts must be enforceable in law and
there is an absolute requirement that the smart contract will be faithful to
the intentions of the parties as expressed in the original legal documentation.
Formal methods provide an attractive route for validation and assurance, and
here we present early results from an investigation of the semantics of
industry-standard legal documentation for OTC derivatives. We explain the need
for a formal representation that combines temporal, deontic and operational
aspects, and focus on the requirements for the temporal aspects as derived from
the legal text. The relevance of this work extends beyond OTC derivatives and
is applicable to understanding the temporal semantics of a wide range of legal
documentation
Political legitimacy and European monetary union: contracts, constitutionalism and the normative logic of two-level games
The crisis of the euro area has severely tested the political authority of the European Union (EU). The crisis raises questions of normative legitimacy both because the EU is a normative order and because the construction of economic and monetary union (EMU) rested upon a theory that stressed the normative value of the depoliticization of money. However, this theory neglected the normative logic of the two-level game implicit in EMU. It also neglected the need for an impartial and publically acceptable constitutional order to acknowledge reasonable disagreements. By contrast, we contend that any reconstruction of the EU's economic constitution has to pay attention to reconciling a European monetary order with the legitimacy of member state governance. The EU requires a two-level contract to meet this standard. Member states must treat each other as equals and be representative of and accountable to their citizens on an equitable basis. These criteria entail that the EU's political legitimacy requires a form of demoicracy that we call ârepublican intergovernmentalismâ. Only rules that could be acceptable as the product of a political constitution among the peoples of Europe can ultimately meet the required standards of political legitimacy. Such a political constitution could be brought about through empowering national parliaments in EU decision-making
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