*Subject*: Re: [isabelle] simp fails on rewriting with "âx :: 'a. f x â a â f x = x"*From*: Lars Noschinski <noschinl at in.tum.de>*Date*: Mon, 08 Jun 2015 16:43:11 +0200*Cc*: "isabelle-users at cl.cam.ac.uk" <isabelle-users at cl.cam.ac.uk>*In-reply-to*: <A7A26D57-0743-4A51-9943-BD251B37EEAA@inria.fr>*References*: <5575A4DC.6070407@in.tum.de> <A7A26D57-0743-4A51-9943-BD251B37EEAA@inria.fr>*User-agent*: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.7.0

On 08.06.2015 16:34, Jasmin Blanchette wrote: > The rule âXâ appears to violate the golden rule of thumb when using > âsimpâ, i.e. that both the rhs and the preconditions should be simpler > than the lhs (see Section 2.5.3 of Concrete Semantics). Surely, âf x > ~= aâ is not simpler than âf xâ. That bad things happen then doesnât > surprise me so muchâ Cheers, Jasmin It is only simpler insofar as that it is literally part of the assumptions. I would not have been surprised if the simplifier had started looping -- after all, it is not really simpler. But refusal to rewrite does not yet fit into my mental model of the simplifier.

**Follow-Ups**:**Re: [isabelle] simp fails on rewriting with "âx :: 'a. f x â a â f x = x"***From:*Tobias Nipkow

**References**:**[isabelle] simp fails on rewriting with "âx :: 'a. f x â a â f x = x"***From:*Lars Noschinski

**Re: [isabelle] simp fails on rewriting with "âx :: 'a. f x â a â f x = x"***From:*Jasmin Blanchette

- Previous by Date: Re: [isabelle] simp fails on rewriting with "âx :: 'a. f x â a â f x = x"
- Next by Date: Re: [isabelle] simp fails on rewriting with "âx :: 'a. f x â a â f x = x"
- Previous by Thread: Re: [isabelle] simp fails on rewriting with "âx :: 'a. f x â a â f x = x"
- Next by Thread: Re: [isabelle] simp fails on rewriting with "âx :: 'a. f x â a â f x = x"
- Cl-isabelle-users June 2015 archives indexes sorted by: [ thread ] [ subject ] [ author ] [ date ]
- Cl-isabelle-users list archive Table of Contents
- More information about the Cl-isabelle-users mailing list