Lean 4 fork for HoTT-compatible kernel extensions (Path types, transport, HITs). Maintained against upstream leanprover/lean4.
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Sebastian Graf a32be44f90
feat: add @[mvcgen_witness_type] attribute for extensible witness classification (#12882)
This PR adds an `@[mvcgen_witness_type]` tag attribute, analogous to
`@[mvcgen_invariant_type]`, that allows users to mark types as witness
types. Goals whose type is an application of a tagged type are
classified as witnesses rather than verification conditions, and appear
in a new `witnesses` section in the `mvcgen` tactic syntax (before
`invariants`).

Witnesses are concrete values the prover supplies (inspired by
zero-knowledge proofs), as opposed to invariants (predicates maintained
across iterations) or verification conditions (propositions to prove).
The test uses a ZK-inspired example where a `SquareRootWitness` value
must be provided by the prover, with the resulting constraint
auto-discharged.

Changes:
- `src/Lean/Elab/Tactic/Do/Attr.lean`: register `@[mvcgen_witness_type]`
tag attribute and `isMVCGenWitnessType` helper
- `src/Lean/Elab/Tactic/Do/VCGen/Basic.lean`: add `witnesses` field to
`State`, three-way classification in `addSubGoalAsVC`
- `src/Std/Tactic/Do/Syntax.lean`: add `witnesses` section syntax
(before `invariants`), extract shared `goalDotAlt`/`goalCaseAlt` syntax
kinds
- `src/Lean/Elab/Tactic/Do/VCGen.lean`: extract shared
`elabGoalSection`, add `elabWitnesses`, wire up witness labeling and
elaboration
- `tests/elab/mvcgenWitnessType.lean`: end-to-end tests for
witness-only, witness with `-leave`, and combined witness+invariant
scenarios

🤖 Generated with [Claude Code](https://claude.com/claude-code)

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
2026-03-11 11:38:05 +00:00
.claude chore: improve CI failure reporting in release checklist (#12786) 2026-03-04 11:55:34 +00:00
.github feat: add lake-ci label to enable full Lake test suite (#12836) 2026-03-10 03:23:35 +00:00
.vscode chore: replace workspace file with .vscode/ settings (#12770) 2026-03-04 01:10:04 +00:00
doc chore: migrate more tests to new test suite (#12809) 2026-03-06 16:52:01 +00:00
images
releases_drafts chore: remove stale release draft notes (#12518) 2026-02-17 19:56:23 +00:00
script feat: unify name demangling with single Lean implementation (#12539) 2026-03-06 12:29:35 +00:00
src feat: add @[mvcgen_witness_type] attribute for extensible witness classification (#12882) 2026-03-11 11:38:05 +00:00
stage0 chore: update stage0 2026-03-11 08:49:43 +00:00
tests feat: add @[mvcgen_witness_type] attribute for extensible witness classification (#12882) 2026-03-11 11:38:05 +00:00
.gitattributes chore: migrate more tests to new test suite (#12809) 2026-03-06 16:52:01 +00:00
.gitignore chore: replace workspace file with .vscode/ settings (#12770) 2026-03-04 01:10:04 +00:00
.gitpod.Dockerfile
.gitpod.yml
.ignore
CMakeLists.txt feat: bundle leantar with Lean (#12822) 2026-03-09 20:10:59 +00:00
CMakePresets.json chore: fix ci for new test suite (#12704) 2026-02-27 23:25:37 +00:00
CODEOWNERS chore: make @hargoniX code owner of the compiler (#10732) 2025-10-10 04:43:38 +00:00
CONTRIBUTING.md
flake.lock chore: update to c++20 (#12117) 2026-02-11 01:17:40 +00:00
flake.nix chore: update to c++20 (#12117) 2026-02-11 01:17:40 +00:00
lean-toolchain chore: relative lean-toolchains (#12652) 2026-02-25 10:23:35 +00:00
LICENSE
LICENSES feat: bundle leantar with Lean (#12822) 2026-03-09 20:10:59 +00:00
README.md doc: update URLs that are currently pointing to redirects (#10397) 2025-09-17 15:50:07 +00:00
RELEASES.md chore: updates to release_checklist.md (#7817) 2025-04-04 03:45:36 +00:00

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