Lean 4 fork for HoTT-compatible kernel extensions (Path types, transport, HITs). Maintained against upstream leanprover/lean4.
e0a29f43d2
This PR changes the `Inhabited` deriving handler for `structure` types
to use default field values when present; this ensures that `{}` and
`default` are interchangeable when all fields have default values. The
handler effectively uses `by refine' {..} <;> exact default` to
construct the inhabitant. (Note: when default field values cannot be
resolved, they are ignored, as usual for ellipsis mode.)
Implementation note: the handler now constructs the `Expr` directly and
adds it to the environment, though the `instance` is still added using
`elabCommand`.
Closes #9463
|
||
|---|---|---|
| .claude | ||
| .github | ||
| .vscode | ||
| doc | ||
| images | ||
| releases_drafts | ||
| script | ||
| src | ||
| stage0 | ||
| tests | ||
| .gitattributes | ||
| .gitignore | ||
| .gitpod.Dockerfile | ||
| .gitpod.yml | ||
| .ignore | ||
| CMakeLists.txt | ||
| CMakePresets.json | ||
| CODEOWNERS | ||
| CONTRIBUTING.md | ||
| flake.lock | ||
| flake.nix | ||
| lean-toolchain | ||
| LICENSE | ||
| LICENSES | ||
| README.md | ||
| RELEASES.md | ||
This is the repository for Lean 4.
About
- Quickstart
- Homepage
- Theorem Proving Tutorial
- Functional Programming in Lean
- Documentation Overview
- Language Reference
- Release notes starting at v4.0.0-m3
- Examples
- External Contribution Guidelines
Installation
See Install Lean.
Contributing
Please read our Contribution Guidelines first.
Building from Source
See Building Lean.