Lean 4 fork for HoTT-compatible kernel extensions (Path types, transport, HITs). Maintained against upstream leanprover/lean4.
ec8811a75a
before code like
def dup (a : Nat) (b : Nat := a) := a + b
def rec : Nat → Nat
| 0 => 1
| n+1 => dup (dup (dup (rec n)))
decreasing_by decreasing_tactic
would run the `decreasing_tactic` 8 tims, because the recursive call
`rec n` gets duplicate due to the default paramter. Similar effects can
be observed due to dependent types or tactics like `cases`.
This is wasteful, and is confusing to the user when they use
`decreasing_by` interactively. Therfore, we now go through the proof
obligations (MVars) and if solving one would imply solving another one,
we assign the mvars to each other accordingly.
This PR is a sibling of #3004.
|
||
|---|---|---|
| .github | ||
| doc | ||
| images | ||
| nix | ||
| script | ||
| src | ||
| stage0 | ||
| tests | ||
| .gitattributes | ||
| .gitignore | ||
| .ignore | ||
| CMakeLists.txt | ||
| CODEOWNERS | ||
| CONTRIBUTING.md | ||
| default.nix | ||
| flake.lock | ||
| flake.nix | ||
| lean-toolchain | ||
| lean.code-workspace | ||
| LICENSE | ||
| LICENSES | ||
| README.md | ||
| RELEASES.md | ||
| shell.nix | ||
This is the repository for Lean 4.
We provide nightly releases and have just begun regular stable point releases.
About
- Quickstart
- Walkthrough installation video
- Quick tour video
- Homepage
- Theorem Proving Tutorial
- Functional Programming in Lean
- Manual
- Release notes starting at v4.0.0-m3
- Examples
- External Contribution Guidelines
- FAQ
Installation
See Setting Up Lean.
Contributing
Please read our Contribution Guidelines first.
Building from Source
See Building Lean.