I'm strongly in favour of an explicit set type. I've been asked for advice by a number of novice Isabelle users and given the same recommendation: go make the development type-check under the old rules. Then the simplifier will start helping you rather than fighting you.
I suppose there might be an alternative strategy involving adapting the simpset or similar to try to standardise blended terms on set operations or function operations. But I don't think this is possible the way Isabelle works - if it were not the default noone then it would not help, and if it were then it would generate years of work in compatibility with the existing proof library. Yours, Thomas. ________________________________________ From: isabelle-dev-boun...@mailbroy.informatik.tu-muenchen.de [isabelle-dev-boun...@mailbroy.informatik.tu-muenchen.de] On Behalf Of Lawrence Paulson [l...@cam.ac.uk] Sent: Thursday, August 11, 2011 11:09 PM To: Florian Haftmann Cc: DEV Isabelle Mailinglist Subject: Re: [isabelle-dev] (Re-)introducing set as a type constructor rather than as mere abbreviation I hope that my position on this question is obvious. And if we decide to revert to the former setup, I would be happy to help track down and fix some problems in theories. Larry On 11 Aug 2011, at 13:43, Florian Haftmann wrote: > Why (I think) the current state concerning sets is a bad idea: > * There are two worlds (sets and predicates) which are logically the > same but syntactically different. Although the logic construction > suggests that you can switch easily between both, in practice you can't _______________________________________________ isabelle-dev mailing list isabelle-...@in.tum.de https://mailmanbroy.informatik.tu-muenchen.de/mailman/listinfo/isabelle-dev The information in this e-mail may be confidential and subject to legal professional privilege and/or copyright. National ICT Australia Limited accepts no liability for any damage caused by this email or its attachments. _______________________________________________ isabelle-dev mailing list isabelle-...@in.tum.de https://mailmanbroy.informatik.tu-muenchen.de/mailman/listinfo/isabelle-dev