max/lean4-htt
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions 2
Lean 4 fork for HoTT-compatible kernel extensions (Path types, transport, HITs). Maintained against upstream leanprover/lean4.
35547 commits 1 branch 0 tags 5.3 GiB
Find a file
Siddharth 1bbd2c183b
feat: BitVec.extract_Lsb'_append_[ite|of_lt|of_le] (#7482) 
This PR implements the
[BV_EXTRACT_CONCAT](6a1a768987/src/rewrite/rewrites_bv.cpp (L1264))
rule from Bitwuzla, which explains how to extract bits from an append.
We first prove a 'master theorem' which has the full case analysis, from
which we rapidly derive the necessary `BV_EXTRACT_CONCAT` theorems:

```lean
theorem extractLsb'_append_eq_ite {v w} {xhi : BitVec v} {xlo : BitVec w} {start len : Nat} :
    extractLsb' start len (xhi ++ xlo) =
    if hstart : start < w
    then
      if hlen : start + len < w
      then extractLsb' start len xlo
      else
        (((extractLsb' (start - w) (len - (w - start)) xhi) ++
            extractLsb' start (w - start) xlo)).cast (by omega)
    else
      extractLsb' (start - w) len xhi

theorem extractLsb'_append_eq_of_lt {v w} {xhi : BitVec v} {xlo : BitVec w}
    {start len : Nat} (h : start + len < w) :
    extractLsb' start len (xhi ++ xlo) = extractLsb' start len xlo

theorem extractLsb'_append_eq_of_le {v w} {xhi : BitVec v} {xlo : BitVec w}
    {start len : Nat} (h : w ≤ start) :
    extractLsb' start len (xhi ++ xlo) = extractLsb' (start - w) len xhi
```

---------

Co-authored-by: Tobias Grosser <github@grosser.es>
2025-03-14 18:25:50 +00:00
.github chore: don't run MacOS aarch64 in merge queue (#7439) 2025-03-11 14:35:10 +00:00
doc chore: post-#7100 cleanup (#7196) 2025-02-23 22:46:22 +00:00
images
nix fix: Windows stage0 linking (#6622) 2025-01-14 09:09:50 +01:00
releases chore: copy v4.17.0 release notes from releases/v4.17.0 branch (#7325) 2025-03-04 11:24:51 +00:00
releases_drafts chore: cherry-pick release notes from releases/v4.15.0 and releases/v4.16.0 (#6520) 2025-01-04 01:25:33 +00:00
script fix: indenting in release notes script (#7326) 2025-03-12 23:02:02 +00:00
src feat: BitVec.extract_Lsb'_append_[ite|of_lt|of_le] (#7482) 2025-03-14 18:25:50 +00:00
stage0 chore: update stage0 2025-03-14 08:29:06 +00:00
tests feat: add BitVec.add_neg_mul to bv_decide (#7486) 2025-03-14 15:28:20 +00:00
.gitattributes
.gitignore
.gitpod.Dockerfile chore: add gitpod configuration (#6382) 2024-12-15 21:38:13 +00:00
.gitpod.yml chore: add gitpod configuration (#6382) 2024-12-15 21:38:13 +00:00
.ignore
CMakeLists.txt feat: upgrade cadical to 2.1.2 (#7347) 2025-03-05 17:58:58 +00:00
CMakePresets.json fix: prevent Task.get deadlocks from threadpool starvation (#6758) 2025-01-23 23:01:39 +00:00
CODEOWNERS
CONTRIBUTING.md
flake.lock feat: upgrade cadical to 2.1.2 (#7347) 2025-03-05 17:58:58 +00:00
flake.nix feat: upgrade cadical to 2.1.2 (#7347) 2025-03-05 17:58:58 +00:00
lean-toolchain
lean.code-workspace
LICENSE
LICENSES
README.md chore: update documentation title and link README to reference (#6409) 2024-12-17 22:18:56 +00:00
RELEASES.md chore: split RELEASES.md into releases/ folder (#6918) 2025-02-03 11:04:09 +00:00

README.md

This is the repository for Lean 4.

About

Installation

See Setting Up Lean.

Contributing

Please read our Contribution Guidelines first.

Building from Source

See Building Lean (documentation source: doc/make/index.md).