Skip to content

feat: limit the use of Classical.choice#12637

Closed
riccardobrasca wants to merge 5 commits intoleanprover:masterfrom
riccardobrasca:riccardo/less_choice
Closed

feat: limit the use of Classical.choice#12637
riccardobrasca wants to merge 5 commits intoleanprover:masterfrom
riccardobrasca:riccardo/less_choice

Conversation

@riccardobrasca
Copy link

@riccardobrasca riccardobrasca commented Feb 22, 2026

An experiment to have a lean toolchain that limit the use of the axiom of choice in basic results.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
@riccardobrasca riccardobrasca changed the title chore: set LEAN_VERSION_IS_RELEASE for v4.29.0 feat: avoid the use of Classical.choice Feb 22, 2026
@riccardobrasca riccardobrasca changed the title feat: avoid the use of Classical.choice feat: limit the use of Classical.choice Feb 22, 2026
@github-actions github-actions bot added the toolchain-available A toolchain is available for this PR, at leanprover/lean4-pr-releases:pr-release-NNNN label Feb 22, 2026
@mathlib-lean-pr-testing
Copy link

Mathlib CI status (docs):

  • ❗ Batteries/Mathlib CI will not be attempted unless your PR branches off the nightly-with-mathlib branch. Try git rebase bfc5d43ad314d1e44a71c3ca761a3640ff23c4fb --onto 527a07b3adbc0c087f75899a10278f4c19a83e31. You can force Mathlib CI using the force-mathlib-ci label. (2026-02-22 09:30:16)

@leanprover-bot
Copy link
Collaborator

Reference manual CI status:

  • ❗ Reference manual CI will not be attempted unless your PR branches off the nightly-with-manual branch. Try git rebase bfc5d43ad314d1e44a71c3ca761a3640ff23c4fb --onto 8038a8b8904f89ad9542c8eda11379f8f006eab1. You can force reference manual CI using the force-manual-ci label. (2026-02-22 09:30:17)

@kim-em
Copy link
Collaborator

kim-em commented Feb 22, 2026

Please remember to close this once it rots.

@kim-em kim-em added the Wont implement We will not implement this request label Feb 22, 2026
· subst hxy
apply k rfl
· exact False.elim <| hxy (inst h)
(x == y) = true → P := fun h ↦ k (inst h)
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This golf looks worth upstreaming :)

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

Labels

toolchain-available A toolchain is available for this PR, at leanprover/lean4-pr-releases:pr-release-NNNN Wont implement We will not implement this request

Projects

None yet

Development

Successfully merging this pull request may close these issues.

4 participants