Repository navigation
Add other/inductive-undeclared-universe - #314
Merged
Merged
Conversation
An inductive type whose type mentions a universe parameter that its block does not declare. Nanoda, nanoclo and nanobruijn accept it; the official kernel rejects it. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01JBWZ9f5kf1XtPVTNdwxiys
Collaborator
|
If it's not a soundness bug per we, just something that we really want checkers to check, it can go to other/. The bugs/ hierarchy should mostly be actual soundness bugs observed in some checker out there. |
It is a check a kernel must make, not an observed proof of False. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01JBWZ9f5kf1XtPVTNdwxiys
jasisz
changed the title
Contributor
Author
|
Makes sense, moved it to |
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Adds a hand-written export to
other/: an inductiveU : Sort uwhose block declares no universe parameters, followed bydef P.{u} : Sort u := Uand two theoremspa pb : P.{0}proved by the two constructors ofU. No checker entry changes.It does not lead to
False(the recursor ofUonly eliminates intoProp); the test is that a checker refuses an inductive type mentioning a universe parameter it does not declare, as the official kernel does for every kind of declaration. No existing test covers undeclared universe parameters.Nanoda, nanoclo and nanobruijn accept it; the official kernel, lean4lean, sokonanoda, tenet and kefir reject it. Reported as ammkrn/nanoda_lib#79.
🤖 Generated with Claude Code
https://claude.ai/code/session_01JBWZ9f5kf1XtPVTNdwxiys