Formal Specification Clause Samples

Formal Specification. Modelling in Event-B typically stars from an initially very abstract representation and is conducted in a series of refinement steps, each adding more detail to the model, until the final model is reached containing all details required for coding or, ideally, automatic code generation. In contrast to this “top-down” modelling methodology, which results in a hierarchy of increasingly more complex models, the XCore ISA is “flat”, i.
View Source
Formal Specification. The purpose of the formal specification phase is to model the cruise control system in Event-B [Abr09b]. Our input for a formal specification of the cruise control system in Event-B is the semi-formal specification which has been de- rived from the informal specification by the process described in Section 4.3. During pilot deployment we developed several guidelines for constructing for- mal specifications in Event-B from semi-formal specifications in our extended Problem Frames approach which will be described in the following. The first step in constructing a formal specification of a control system in Event-B is to think of the refinement strategy, i.e., a strategy about structur- ing the refinement levels of a formal specification in Event-B. Since Event-B supports so called contexts which describe the static aspects of the system to be modelled and so called machines which describe the dynamic aspects of the system to be modelled one has to think about a refinement strategy for contexts as well as one for machines. During our first experiments of formally modelling the cruise control system in Event-B we found out that our semi-formal requirements specification with different abstraction levels can be mapped to a formal specification in Event-B in the following way: Each problem diagram is modelled as a separate machine with its as- sociated context. Elaborations of an abstract diagram into a more concrete one are real- ized in Event-B by refinement of the machine and its associated con- text. Projections of a problem diagram into two or more subproblems are re- alized in Event-B by shared-variable decomposition [Abr09a] with some changes. Each phenomenon defined in a problem diagram is modelled either as a constant or a variable in Event-B. Abstract phenomena which will be elaborated later are realized in Event-B using records. Elaborations of phenomena in problem diagrams are realized in Event- B using data refinement. events and/or invariants. Table 4.2 shows this mapping of Problem Frame elements to Event-B elements in a compact form. We applied this refinement strategy on the cruise control system. Figure
View Source

Related to Formal Specification

  • Technical Specifications The purpose of the Technical Specifications (TS), is to define the technical characteristics of the Goods and Related Services required by the Procuring Entity. The Procuring Entity shall prepare the detailed TS consider that:

  • Escrow Format Specification Deposit’s Format. Registry objects, such as domains, contacts, name servers, registrars, etc. will be compiled into a file constructed as described in draft-▇▇▇▇▇-▇▇▇▇▇▇▇-registry-data-escrow, see Part A, Section 9, reference 1 of this Specification and draft-▇▇▇▇▇-▇▇▇▇▇▇▇-dnrd-objects-mapping, see Part A, Section 9, reference 2 of this Specification (collectively, the “DNDE Specification”). The DNDE Specification describes some elements as optional; Registry Operator will include those elements in the Deposits if they are available. If not already an RFC, Registry Operator will use the most recent draft version of the DNDE Specification available at the Effective Date. Registry Operator may at its election use newer versions of the DNDE Specification after the Effective Date. Once the DNDE Specification is published as an RFC, Registry Operator will implement that version of the DNDE Specification, no later than one hundred eighty (180) calendar days after. UTF-8 character encoding will be used.

  • DAF Specifications Developer shall submit initial specifications for the DAF, including System Protection Facilities, to Connecting Transmission Owner and NYISO at least one hundred eighty (180) Calendar Days prior to the Initial Synchronization Date; and final specifications for review and comment at least ninety (90) Calendar Days prior to the Initial Synchronization Date. Connecting Transmission Owner and NYISO shall review such specifications to ensure that the DAF are compatible with the technical specifications, operational control, and safety requirements of the Connecting Transmission Owner and NYISO and comment on such specifications within thirty (30) Calendar Days of Developer’s submission. All specifications provided hereunder shall be deemed to be Confidential Information.

  • General specifications For the purpose of this Regulation, the vehicle shall fulfil the following requirements:

  • Service Specification The Parties have agreed upon the scope and specification of the Services provided under this Service Agreement in the Service Specification.