[Agda] Overloaded constructor trouble

[Thorsten Altenkirch]

Thank you, but I don't think this works for me. I need the definitions in various places.

Thorsten

On 28/08/2020, 10:28, "Peter Thiemann" <thiemann at informatik.uni-freiburg.de> wrote:

    Hi Thorsten,

    modules are your friend, again.

    module _ where
      open import Data.Nat (suc)
      inj-suc : {m n : ℕ} → suc m ≡ suc n → m ≡ n
      inj-suc = {!!} 

    or you just open Fin for the definitions where you need it.

    -Peter

    PS I ran into this issue when using ==-Reasoning and ~=-Reasoning in the same module


    On 28. August 2020 at 11:22:30, Thorsten Altenkirch (thorsten.altenkirch at nottingham.ac.uk) wrote:
    > Ok, let’s say I want to show that suc is injective:
    >  
    > open import Relation.Binary.PropositionalEquality
    > open import Data.Nat
    >  
    > inj-suc : {m n : ℕ} → suc m ≡ suc n → m ≡ n
    > inj-suc = {!!}
    >  
    > So far so good but at some point I decide to use Fin as well.
    >  
    > open import Relation.Binary.PropositionalEquality
    > open import Data.Nat
    > open import Data.Fin
    >  
    > inj-suc : {m n : ℕ} → suc m ≡ suc n → m ≡ n
    > inj-suc = {!!}
    >  
    > But now things get yellow ☹ Ok agda cannot infer which suc I want to use, even though only  
    > one actually works.
    >  
    > This is annoying, especially if you are writing a book and are reluctant to write
    >  
    > inj-suc : {m n : ℕ} → _≡_ {A = ℕ} (suc m) (suc n) → m ≡ n
    > inj-suc = {!!}
    >  
    > instead (this is ugly).
    >  
    > I have two questions: are there any good workarounds? And is there a way to fix it?
    >  
    > Cheers,
    > Thorsten
    >  
    >  
    >  
    > This message and any attachment are intended solely for the addressee
    > and may contain confidential information. If you have received this
    > message in error, please contact the sender and delete the email and
    > attachment.
    >  
    > Any views or opinions expressed by the author of this email do not
    > necessarily reflect the views of the University of Nottingham. Email
    > communications with the University of Nottingham may be monitored
    > where permitted by law.
    >  
    >  
    >  
    >  
    > _______________________________________________
    > Agda mailing list
    > Agda at lists.chalmers.se
    > https://lists.chalmers.se/mailman/listinfo/agda
    >  





This message and any attachment are intended solely for the addressee
and may contain confidential information. If you have received this
message in error, please contact the sender and delete the email and
attachment. 

Any views or opinions expressed by the author of this email do not
necessarily reflect the views of the University of Nottingham. Email
communications with the University of Nottingham may be monitored 
where permitted by law.