This paper presents a method for automatically translating natural language speciications into temporal logic. Using this method, users may express complex speciications in relatively free natural language , allowing multi-sentence speciications, the use of pronouns instead of repeating the description of previously mentioned objects and complex temporal relations. These speciications are trans...

All known crystal structures of rhinoviruses have some uninterpreted electron density on their fivefold axes at a distance of about 152 +/- 3 A from the viral center. This density had been assumed to be a Ca2+ ion, based on its shape, height, and the presence of Ca2+ ions in the crystallization solutions. Difference electron density maps between EGTA-soaked crystals of human rhinovirus 14 (HRV1...

Speciication languages are best used in environments that provide eeective theorem proving. Having such support available, it is feasible to contemplate forms of typechecking that can use the services of a theorem prover. This allows interesting extensions to the type systems provided for speciication languages. I describe one such extension called \predicate subtyping" and illustrate its utili...

This paper proposes an application of programming environments generation to structured document manipulation. We use the Centaur system as a formal tool to model and implement logical and physical document structure, logical structure editing, layout processing, format conversion, and document queries, for a sample class of documents: scientiic articles including equations and gures. We suppor...

The structure of zeolite clinoptilolite and the coordination of extraframework cations (Ca, Ba, Na and K) by framework oxygen atoms are examined by density functional theory (DFT) using two methods: the ONIOM two-layer model (DFT/MM) and periodic DFT. Both ONIOM and periodic model calculations predict correctly the clinoptilolite structure and find configurations with Al ? Si substitution at th...