Abstract: A computer-implemented method of evaluating a task network. The task network comprises primitive tasks which represent actions, compound tasks which represent a plurality of tasks, goal tasks which represent desired goals, and one or more constraints associated with the tasks of the task network. A library of network fragments is provided, where each network fragment comprises a plurality of tasks and one or more associated constraints, and a plurality of network fragments of the library of network fragments have associated with them an abnormality level. One or more network fragments of the library of network fragments are matched with a plurality of tasks and one or more associated constraints of the task network. A normality score is determined for the task network using the abnormality levels associated with the one or more matching network fragments.

Abstract: Process for producing Sevoflurane anaesthetic which comprises reacting hexafluoroisopropyl alcohol with essentially pure bis(fluoromethyl)ether. The bis(fluoromethyl)ether is preferably obtained by the reaction of formaldehyde with hydrogen fluoride.

Abstract: A process for the production of hydrofluorocarbons, in particular hydrofluoroalkanes such as difluoromethane, which comprises contacting an .alpha.-fluoro-ether, in particular a fluorinated dialkyl ether such as bis(fluoromethyl)ether in the liquid phase with a Lewis acid such as a fluoride of Nb, Sb, B, Ta, Al or Ti.

Abstract: A process for the production of a hydro(halo)fluorocarbon which comprises heating an .alpha.-fluoroether in the vapor phase at elevated temperature. .alpha.-fluoroethers are obtained by reacting a non-enolisable aldehyde with hydrogen fluoride to form an intermediate and reacting the intermediate with an alcohol or a halogenating agent. Novel .alpha.-fluoroethers are also provided.

Abstract: This invention relates to a process for the production of 1,1,2,2- and/or 1,1,1,2-tetrafluoroethanes, and in particular to a process for the production of 1,1,1,2-tetrafluoroethane.

Abstract: A composition comprising bis(fluoromethyl)ether and less than an equimolar amount of water, a process for the production of the composition comprising contacting formaldehyde with hydrogen fluoride and separating at least some of the by-product water from bis(fluoromethyl)ether, and use of the composition for the production of difluoromethane.

Abstract: A process for the production of a hydro(halo)fluorocarbon which comprises heating an .alpha.-fluoroether in the vapor phase at elevated temperature. .alpha.-fluoroethers are obtained by reacting a non-enolisable aldehyde with hydrogen fluoride to form an intermediate and reacting the intermediate with an alcohol or a halogenating agent. Novel .alpha.-fluoroethers are also provided.

Abstract: A process for the production of a hydro(halo)fluorocarbon which comprises heating an .alpha.-fluoroether in the vapour phase at elevated temperature. .alpha.-fluoroethers are obtained by reacting a non-enolisable aldehyde with hydrogen fluoride to form an intermediate and reacting the intermediate with an alcohol or a halogenating agent. Novel .alpha.-fluoroethers are also provided.

Abstract: A composition comprising bis(fluoromethyl)ether and less than an equimolar amount of water, a process for the production of the composition comprising contacting formaldehyde with hydrogen fluoride and separating at least some of the by-product water from bis(fluoromethyl)ether, and use of the composition for the production of difluoromethane.

Abstract: A process for the production of a hydro(halo)fluorocarbon which comprises heating an .alpha.-fluoroether in the vapor phase at elevated temperature. .alpha.-fluoroethers are obtained by reacting a non-enolizable aldehyde with hydrogen fluoride to form an intermediate and reacting the intermediate with an alcohol or a halogenating agent. Novel .alpha.-fluoroethers are also provided.

Abstract: A process for the production of hydrofluorocarbons, in particular hydrofluoroalkanes such as difluoromethane, which comprises contacting an .alpha.-fluoro-ether, in particular a fluorinated dialkyl ether such as bis(fluoromethyl)ether in the liquid phase with a Lewis acid such as a fluoride of Nb, Sb, B, Ta, Al or Ti.

Abstract: A composition comprising bis(fluoromethyl)ether and less than an equimolar amount of water, a process for the production of the composition comprising contacting formaldehyde with hydrogen fluoride and separating at least some of the by-product water from bis(fluoromethyl)ether, and use of the composition for the production of difluoromethane.

Abstract: 4,4'-difluoro-benzophenone is prepared from 4,4'-diamino-diphenylmethane by diazotization in anhydrous or concentrated aqueous hydrogen fluoride and decomposition of the diazonium fluoride thus produced in the presence of nitrous acid or nitrite as oxidizing agent.