Hi Larry, if you want to put the definitions and the basic properties in Main, then Fun.thy would probably be the place. But then I would argue that the syntax should be hidden, as users might want to use these symbols for something else.

For the advanced material, do you need some theorems from HOL-Cardinals or just the syntax from HOL-Library.Cardinal_Notations in addition to what is already there in Main about cardinals? If it is only the syntax, then a separate theory in HOL-Library is probably a good fit. Otherwise, a separate theory in HOL-Cardinals would make sense. Dmitriy > On 22 Jan 2019, at 15:58, Lawrence Paulson <l...@cam.ac.uk> wrote: > > I’m trying to install some of my new material and I’m wondering what to do > with equipollence and related concepts: > > definition eqpoll :: "'a set ⇒ 'b set ⇒ bool" (infixl "≈" 50) > where "eqpoll A B ≡ ∃f. bij_betw f A B" > > definition lepoll :: "'a set ⇒ 'b set ⇒ bool" (infixl "≲" 50) > where "lepoll A B ≡ ∃f. inj_on f A ∧ f ` A ⊆ B" > > definition lesspoll :: "'a set ⇒ 'b set ⇒ bool" (infixl ‹≺› 50) > where "A ≺ B == A ≲ B ∧ ~(A ≈ B)" > > The raw definitions are extremely simple and could even be installed in the > main Isabelle/HOL distribution. The basic properties of these concepts > require few requisites. However, more advanced material requires the > Cardinals development. > > Where do people think these definitions and proofs should be installed? > > Larry > >> On 27 Dec 2018, at 20:29, Makarius <makar...@sketis.net> wrote: >> >> On 27/12/2018 17:45, Traytel Dmitriy wrote: >>> Hi Larry, >>> >>> the HOL-Cardinals library might be just right for the purpose: >>> >>> theory Scratch >>> imports "HOL-Cardinals.Cardinals" >>> begin >>> >>> lemma "|A| ≤o |B| ⟷ (∃f. inj_on f A ∧ f ` A ⊆ B)" >>> by (rule card_of_ordLeq[symmetric]) >>> >>> lemma "|A| =o |B| ⟷ (∃f. bij_betw f A B)" >>> by (rule card_of_ordIso[symmetric]) >>> >>> lemma >>> assumes "|A| ≤o |B|" "|B| ≤o |A|" >>> shows "|A| =o |B|" >>> by (simp only: assms ordIso_iff_ordLeq) >>> >>> end >>> >>> The canonical entry point for the library is the above >>> HOL-Cardinals.Cardinals. Many of the theorems and definitions are already >>> in Main, because the (co)datatype package is based on them. The syntax is >>> hidden in main—one gets it by importing HOL-Library.Cardinal_Notations >>> (which HOL-Cardinals.Cardinals does transitively). >> >> It would be great to see this all consolidated and somehow unified, i.e. >> some standard notation in Main as proposed by Larry (potentially as >> bundles as proposed by Florian), and avoidance of too much no_syntax >> remove non-standard notation from Main. >> >> >> Makarius > _______________________________________________ isabelle-dev mailing list isabelle-...@in.tum.de https://mailmanbroy.informatik.tu-muenchen.de/mailman/listinfo/isabelle-dev