New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

Positivity condition violation when using already-defined inductive datatype in definition of another inductive datatype #501

Open

MM45 opened this issue Dec 11, 2023 · 0 comments

Contributor

MM45 commented Dec 11, 2023

The following raises an error stating the datatype does not respect the positivity condition :

require import List.

type 'a tree = [
    Empty
  | Node of 'a & ('a tree) list
].

Swapping tree and list types around works just fine:

require import List.

type 'a tree = [
    Empty
  | Node of 'a & ('a list) tree
].

The text was updated successfully, but these errors were encountered:

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment