Group Refinement Sample Clauses

Group Refinement. One of the project industrial partners (Bosch) has identified a recurring refinement pattern that did not fit well the existing laws of refinement. It is a case of atomicity refinement where a previously atomic action (event) is split into a number of steps which combined effect achieves the effect of the abstract atomic event. The Event-B approach is to introduce new variables in a refinement machine and thus have a hidden concrete state on which the steps are defined. There is a further event summarising the effect of the computations accomplished on the hidden state and explicitly relating it to the abstract state. This is the event for which the refinement relation is demonstrated while the events defining the actual computation steps would have no formal link to the abstract event. When the hidden state does not naturally follow as a part of the modelling process this refinement style leads to a contrived model. There appear auxiliary variables and auxiliary events that play no part in the characterisation of the system behaviour but are a codification of the refinement relation to an abstract model. Since such elements accumulate during refinement this has a profound effect on the development of a large model.
AutoNDA by SimpleDocs
Group Refinement. In this work one obvious source of inspiration is the Classical B method [5] where an abstract atomic statement may be refined into an operation which body is made of a sequence of assignments. However, the introduction of the semicolon operator in Event-B is a substantial change affecting most aspects of the method. This would also reintroduce one of the problems of the Classical B that Event-B tries to address: proof scalability. Accumulation of sequential composition through refinement steps may result in unmanageable proof obligations. It is also more difficult to conduct subsequent refinement of events with sequential actions. Actions Systems [6] has an atomicity refinement technique where one can refine an atomic action into a loop of new actions[7] . This is general enough to address the problem but, seemingly, the associated proof cost is prohibitively high and there is no evidence that such proofs may be efficiently mechanised. The challenge was addressed by offering a method that lets a modeller to select an alternative set of refinement laws whenever the identified pattern of refinement is encountered. The new refinement laws are based on a different interpretation of a model: split refinement (a case of event refinement when an abstract event is refined into two or more concrete alternatives) is understood as a refinement into a composite event made of the concrete events arranged in some way. One simple arrangement case is when the concrete events are understood to execute sequentially. Then the refinement relation is demonstrated for the after-state produced by executing one event after another. The method is not limited to sequential composition and there is also a form of parallel composition. An essential property of the method is that the group refinement relation is demonstrated not just for a single arrangement of concrete events but for a whole set of traces of concrete events. There is a simple notation for the removal of undesired traces and constraining the model to specific traces. For each trace there appears one instance of action simulation proof obligation (and possibly other refinement and consistency proof obligations). Thus, for practical reasons, it is necessary to keep number of traces low. This is best accomplished by doing small refinement steps with few concrete events.
Group Refinement. There is a wiki page[9] briefly introducing the approach and the tool • Slides
Group Refinement. The immediate plan is to produce a technical report on the semantics of group refinement during the first quarter of 2011. Long term plans are the tool maintenance and the investigation of the possibility of more expressive form of group refinement permitting branches and loops.

Related to Group Refinement

  • Access Toll Connecting Trunk Group Architecture 9.2.1 If CBB chooses to subtend a Verizon access Tandem, CBB’s NPA/NXX must be assigned by CBB to subtend the same Verizon access Tandem that a Verizon NPA/NXX serving the same Rate Center Area subtends as identified in the LERG.

  • FABRICATION Making up data or results and recording or reporting them.

  • Innovative Scheduling Schedules which are inconsistent with the Collective Agreement provisions may be developed in order to improve quality of working life, support continuity of resident care, ensure adequate staffing resources, and support cost-efficiency. The parties agree that such innovative schedules may be determined locally by the Home and the Union subject to the following principles:

  • Durable Medical Equipment (DME), Medical Supplies, Prosthetic Devices, Enteral Formula or Food, and Hair Prosthesis (Wigs) This plan covers durable medical equipment and supplies, prosthetic devices and enteral formula or food as described in this section. Durable Medical Equipment (DME) DME is equipment which: • can withstand repeated use; • is primarily and customarily used to serve a medical purpose; • is not useful to a person in the absence of an illness or injury; and • is for use in the home. DME includes supplies necessary for the effective use of the equipment. This plan covers the following DME: • wheelchairs, hospital beds, and other DME items used only for medical treatment; and • replacement of purchased equipment which is needed due to a change in your medical condition or if the device is not functional, no longer under warranty, or cannot be repaired. DME may be classified as a rental item or a purchased item. In most cases, this plan only pays for a rental DME up to our allowance for a purchased DME. Repairs and supplies for rental DME are included in the rental allowance. Preauthorization may be required for certain DME and replacement or repairs of DME. Medical Supplies Medical supplies are consumable supplies that are disposable and not intended for re- use. Medical supplies require an order by a physician and must be essential for the care or treatment of an illness, injury, or congenital defect. Covered medical supplies include: • essential accessories such as hoses, tubes and mouthpieces for use with medically necessary DME (these accessories are included as part of the rental allowance for rented DME); • catheters, colostomy and ileostomy supplies, irrigation trays and surgical dressings; and • respiratory therapy equipment. Diabetic Equipment and Supplies This plan covers diabetic equipment and supplies for the treatment of diabetes in accordance with R.I. General Law §27-20-30. Covered diabetic equipment and supplies include: • therapeutic or molded shoes and inserts for custom-molded shoes for the prevention of amputation; • blood glucose monitors including those with special features for the legally blind, external insulin infusion pumps and accessories, insulin infusion devices and injection aids; and • lancets and test strips for glucose monitors including those with special features for the legally blind, and infusion sets for external insulin pumps. The amount you pay differs based on whether the equipment and supplies are bought from a durable medical equipment provider or from a pharmacy. See the Summary of Pharmacy Benefits and the Summary of Medical Benefits for details. Coverage for some diabetic equipment and supplies may only be available from either a DME provider or from a pharmacy. Visit our website to determine if this is applicable or call our Customer Service Department. Prosthetic Devices Prosthetic devices replace or substitute all or part of an internal body part, including contiguous tissue, or replace all or part of the function of a permanently inoperative or malfunctioning body part and alleviate functional loss or impairment due to an illness, injury or congenital defect. Prosthetic devices do not include dental prosthetics. This plan covers the following prosthetic devices as required under R.I. General Law § 27-20-52: • prosthetic appliances such as artificial limbs, breasts, larynxes and eyes; • replacement or adjustment of prosthetic appliances if there is a change in your medical condition or if the device is not functional, no longer under warranty and cannot be repaired; • devices, accessories, batteries and supplies necessary for prosthetic devices; • orthopedic braces except corrective shoes and orthotic devices used in connection with footwear; and • breast prosthesis following a mastectomy, in accordance with the Women’s Health and Cancer Rights Act of 1998 and R.I. General Law 27-20-29. The prosthetic device must be ordered or provided by a physician, or by a provider under the direction of a physician. When you are prescribed a prosthetic device as an inpatient and it is billed by a provider other than the hospital where you are an inpatient, the outpatient benefit limit will apply. Enteral Formulas or Food (Enteral Nutrition) Enteral formula or food is nutrition that is absorbed through the intestinal tract, whether delivered through a feeding tube or taken orally. Enteral nutrition is covered when it is the sole source of nutrition and prescribed by the physician for home use. In accordance with R.I. General Law §27-20-56, this plan covers enteral formula taken orally for the treatment of: • malabsorption caused by Crohn’s Disease; • ulcerative colitis; • gastroesophageal reflux; • chronic intestinal pseudo obstruction; and • inherited diseases of amino acids and organic acids. Food products modified to be low protein are covered for the treatment of inherited diseases of amino acids and organic acids. Preauthorization may be required. The amount that you pay may differ depending on whether the nutrition is delivered through a feeding tube or taken orally. When enteral formula is delivered through a feeding tube, associated supplies are also covered. Hair Prosthesis (Wigs) This plan covers hair prosthetics (wigs) worn for hair loss suffered as a result of cancer treatment in accordance with R.I. General Law § 27-20-54 and subject to the benefit limit and copayment listed in the Summary of Medical Benefits. This plan will reimburse the lesser of the provider’s charge or the benefit limit shown in the Summary of Medical Benefits. If the provider’s charge is more than the benefit limit, you are responsible for paying any difference. Early Intervention Services (EIS) This plan covers Early Intervention Services in accordance with R.I. General Law §27- 20-50. Early Intervention Services are educational, developmental, health, and social services provided to children from birth to thirty-six (36) months. The child must be certified by the Rhode Island Department of Human Services (DHS) to enroll in an approved Early Intervention Services program. Services must be provided by a licensed Early Intervention provider and rendered to a Rhode Island resident. Members not living in Rhode Island may seek services from the state in which they reside; however, those services are not covered under this plan. Early Intervention Services as defined by DHS include but are not limited to the following: • speech and language therapy; • physical and occupational therapy; • evaluation; • case management; • nutrition; • service plan development and review; • nursing services; and • assistive technology services and devices.

  • Infrastructure (a) The Borrower has and will maintain a sufficient infrastructure to conduct its business as presently conducted and as contemplated to be conducted following its execution of this Agreement.

  • Cooperative Procurement To the maximum extent permitted by applicable law, we agree that this Agreement may be used as a cooperative procurement vehicle by eligible jurisdictions. We reserve the right to negotiate and customize the terms and conditions set forth herein, including but not limited to pricing, to the scope and circumstances of that cooperative procurement.

  • Innovative Unit Scheduling Schedules other than those included in Articles 13.01 and 13.02 may be developed in order to improve quality of working life, support continuity of patient care, ensure adequate staffing resources, and support cost-efficiency. The parties agree that such innovative schedules may be determined locally by the Hospital and the Union subject to the following principles:

  • Pipelines Developer shall have no interest in the pipeline gathering system, which gathering system shall remain the sole property of Operator or its Affiliates and shall be maintained at their sole cost and expense.

  • TRENCH SHORING If this Contract is in excess of $25,000 and is for the excavation of any trench deeper than five (5) feet, Contractor must submit and obtain District’s approval and acceptance, in advance of excavation, of a detailed plan showing the design of shoring, bracing, sloping, or other provisions to be made for worker protection from the hazard of caving ground during the excavation of such trench or trenches. If the plan varies from the shoring system standards, the plan shall be prepared by a registered civil or structural engineer.

  • Television Equipment Recycling If this Contract is for the purchase or lease of covered television equipment, then Contractor certifies that it is compliance with Subchapter Z, Chapter 361 of the Texas Health and Safety Code related to the Television Equipment Recycling Program.

Time is Money Join Law Insider Premium to draft better contracts faster.