This PR makes the automatic first token detection in tactic docs much
more robust, in addition to making it work in modules and other contexts
where builtin tactics are not in the environment. It also adds the
ability to override the tactic's first token as the user-visible name.
Previously, first token detection would look up the parser descriptor in
the environment and process its syntax. This would be incorrect for
builtin parsers, as well as for modules in which the definition is not
loaded. Now, it instead consults the Pratt parsing table for the
`tactic` syntax category. Tests are added that ensure this keeps working
in modules, and also that the first token of all tactics that ship with
Lean are either detected unambiguously or annotated to remove ambiguity.
Closes#12038.
This PR fixes a bug where the unknown identifier code actions were
broken in NeoVim due to the language server not properly setting the
`data?` field for all code action items that it yields.
This PR adds support for offset terms in `SymM`. This is essential for
handling equational theorems for functions that pattern match on natural
numbers in `Sym.simp`. Without this, it cannot handle simple examples
such as
```lean
def pw (n : Nat) : Nat :=
match n with
| 0 => 1
| n+1 => 2 * pw n
example : pw 4 = 16 := by
sym_simp [pw.eq_1, pw.eq_2]
example : pw (a + 2) = 2 * (2 * pw a) := by
sym_simp [pw.eq_2]
```
This PR adds `lake shake` as a built-in Lake command, moving the shake
functionality from `script/Shake.lean` into the Lake CLI.
## Motivation
Per discussion with @Kha and @tydeu, having shake as a top-level Lake
command is preferable to `lake exe shake` because:
- Avoids the awkwardness of accessing core tools via `lake exe`
- Compiles shake into the Lake binary, avoiding lakefile issues
- No benefit to lazy compilation on user machines for this tool
## Changes
- Move shake logic from `script/Shake.lean` to
`src/lake/Lake/CLI/Shake.lean`
- Add `lake shake` command dispatch in `Lake/CLI/Main.lean`
- Add help text in `Lake/CLI/Help.lean`
- Remove the standalone shake executable from `script/lakefile.toml`
## Usage
```
lake shake [OPTIONS] [<MODULE>...]
```
See `lake shake --help` for full documentation.
🤖 Prepared with Claude Code
---------
Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: Mac Malone <mac@lean-fro.org>
Co-authored-by: Sebastian Ullrich <sebasti@nullri.ch>
This PR changes the default of `enableArtifactCache` to use the
workspace's `enableArtifactCache` setting if the package is a dependency
and `LAKE_ARTIFACT_CACHE` is not set. This means that dependencies of a
project with `enableArtifactCache` set will also, by default, use Lake's
local artifact cache.
This PR adds `simpControl`, a simproc that handles control-flow
expressions such as `if-then-else`. It simplifies conditions while
avoiding unnecessary work on branches that won't be taken.
The key behavior of `simpControl`:
- Simplifies the condition of `if-then-else` expressions
- If the condition reduces to `True` or `False`, returns the appropriate
branch, and continue simplifying.
- If the condition simplifies to a new expression, rebuilds the
`if-then-else` with the simplified condition (synthesizing a new
`Decidable` instance), and mark it as "done". That is, simplifier main
loop will not visit branches.
- Does **not** visit branches unless the condition becomes `True` or
`False`
This is useful for symbolic simplification where we want to avoid
wasting effort
simplifying branches that may be eliminated after the condition is
resolved.
This PR also fixes a bug in `Sym/Simp/EvalGround.lean`, and adds some
helper functions.
This PR adds `Sym.Simp.evalGround`, a simplification procedure for
evaluating ground terms of builtin numeric types. It is designed for
`Sym.simp`.
Key design differences from `Meta.Simp` simprocs:
- Pure value extraction: `getValue?` functions are `OptionT Id` rather
than
`MetaM`, avoiding `whnf` overhead since `Sym` maintains canonical forms
- Specialized predicate lemmas: comparisons use pre-proved lemmas like
`Int.lt_eq_true` applied with `rfl`, avoiding `Decidable` instance
reconstruction at each call site
- Type dispatch via `match_expr`: assumes standard instances, no
synthesis
Supported types: `Nat`, `Int`, `Rat`, `Fin n`, `BitVec n`,
`UInt8/16/32/64`,
`Int8/16/32/64`.
Supported operations: arithmetic (`+`, `-`, `*`, `/`, `%`, `^`), bitwise
(`&&&`, `|||`, `^^^`, `~~~`), shifts (`<<<`, `>>>`), comparisons (`<`,
`≤`,
`>`, `≥`, `=`, `≠`, `∣`), and boolean predicates (`==`, `!=`).
This PR fixes an issue where attributes like `@[irreducible]` would not
be allowed under the module system unless combined with `@[exposed]`,
but the former may be helpful without the latter to ensure downstream
non-`module`s are also affected.
Fixes#12025
Drastically speeds up `isTracingEnabledFor` in the common case, which
has evolved from "no options set" to "`Elab.async` and probably some
linter options set but no `trace`".
## Breaking changes
`Lean.Options` is now an opaque type. The basic but not all of the
`KVMap` API has been redefined on top of it.
This PR allows 'Go to Definition' to look through reducible definition
when looking for typeclass instance projections.
Specifically, this means that using 'Go to Definition' on uses of
`GT.gt` will now yield the corresponding `LT` instance as well.
This PR splits up the SCC that the compiler manages into (potentially)
multiple ones after
performing lambda lifting. This aids both the closed term extractor and
the elimDeadBranches pass as
they are both negatively influenced when more declarations than required
are within one SCC.
This PR fixes an issue where go-to-definition would jump to the wrong
location in presence of async theorems.
While the elaborator does not explicitly depend on `FVar`s not being
reused between declarations, the language server turned out to do so. As
we would have to split the name generator in any case as soon as we add
any parallelism within proofs, we now do so for any async code in order
to uphold this invariant again.
---------
Co-authored-by: mhuisi <mhuisi@protonmail.com>
This PR adds support for simplifying the arguments of over-applied and
under-applied function application terms in `Sym.simp`, completing the
implementation for all three congruence strategies (fixed prefix,
interlaced, and congruence theorems).
This PR implements support for auto-generated congruence theorems in
`Sym.simp`, enabling simplification of functions with complex argument
dependencies such as proof arguments and `Decidable` instances.
Previously, `Sym.simp` used basic congruence lemmas (`congrArg`,
`congrFun`, `congrFun'`, `congr`) to construct proofs when simplifying
function arguments. This approach is efficient for simple cases but
cannot handle functions with dependent proof arguments or `Decidable`
instances that depend on earlier arguments.
The new `congrThm` function applies pre-generated congruence theorems
(similar to the main simplifier) to handle these complex cases.
This PR fixes the `floatLetIn` pass to not move variables in case it
could break linearity (owned variables being passed with RC 1). This
mostly improves the situation in the parser which previously had many
functions that were supposed to be linear in terms of `ParserState` but
the compiler made them non-linear. For an example of how this affected
parsers:
```lean-4
def optionalFn (p : ParserFn) : ParserFn := fun c s =>
let iniSz := s.stackSize
let iniPos := s.pos
let s := p c s
let s := if s.hasError && s.pos == iniPos then s.restore iniSz iniPos else s
s.mkNode nullKind iniSz
```
previously moved the `let iniSz := ...` declaration into the `hasError`
branch. However, this means that at the point of calling the inner
parser (`p c s`), the original state `s` needs to have RC>1 because it
is used later in the `hasError` branch, breaking linearity. This fix
prevents such moves, keeping `iniSz` before the `p c s` call.
This PR adds missing type checking for pattern variables during pattern
matching/unification to prevent incorrect matches.
Previously, the pattern matcher could incorrectly match expressions even
when pattern variable types were incompatible with the matched subterm
types. For example, a pattern like `x` where `x : BitVec 0` could match
any term, ignoring the specific type constraint on `x`.
This PR introduces a two-phase type checking approach:
1. **Static analysis** (`mkCheckTypeMask`): Identifies which pattern
variables require type checking based on their syntactic position.
Variables that appear only as arguments to function applications skip
checking (the application structure already constrains their types),
while variables in function position, binder contexts, or standalone
positions must be checked.
2. **Runtime validation**: During matching, when a pattern variable is
assigned, its type is checked against the matched subterm's type if
flagged by the mask. Checking uses `withReducible` to balance soundness
and performance.
The PR also adds helper functions for debugging (`Sym.mkMethods`,
`Sym.simpWith`, `Sym.simpGoal`) and fixes a minor issue where
`Theorem.rewrite` could return `.step` with identical expressions
instead of `.rfl`.Body:
This PR optimizes congruence proof construction in `Sym.simp` by
avoiding
`inferType` calls on expressions that are less likely to be cached.
Instead of
inferring types of expressions like `@HAdd.hAdd Nat Nat Nat instAdd 5`,
we infer
the type of the function prefix `@HAdd.hAdd Nat Nat Nat instAdd` and
traverse
the forall telescope.
The key insight is that function prefixes are more likely shared across
many call sites
(e.g., all `Nat` additions use the same `@HAdd.hAdd Nat Nat Nat
instAdd`), so they
benefit from `inferType` caching.
Benchmark results show improvements on workloads with shared function
prefixes:
- `many_rewrites_5000`: 48.8ms → 43.1ms (-12%)
- `term_tree_5000`: 53.4ms → 30.5ms (-43%)
This PR implements a new strategy for simplifying `have`-telescopes in
`Sym.simp` that achieves linear kernel type-checking time instead of
quadratic.
## Problem
When simplifying deep `have`-telescopes, the previous approach using
`have_congr'` produced proofs that type-checked in quadratic time. The
simplifier itself was fast, but the kernel became the bottleneck for
large telescopes.
For example, at n=100:
- **Before**: simp = 2.4ms, kernel = **225ms**
- **After**: simp = 3.5ms, kernel = **10ms**
The quadratic behavior occurred because the kernel creates fresh free
variables for each binder when type-checking, destroying sharing and
producing O(n²) intermediate terms.
## Solution
We transform sequential `have`-telescopes into a parallel
beta-application form:
```
have x₁ := v₁; have x₂ := v₂[x₁]; b[x₁, x₂]
↓ (definitionally equal)
(fun x₁ x₂' => b[x₁, x₂' x₁]) v₁ (fun x₁ => v₂[x₁])
```
This parallel form leverages the efficient simplifier for lambdas in
`Sym.simp`. This form enables:
1. Independent simplification of each argument
2. Proof construction using standard congruence lemmas
3. Linear kernel type-checking time
The algorithm has three phases:
1. **`toBetaApp`**: Transform telescope → parallel beta-application
2. **`simpBetaApp`**: Simplify using `congr`/`congrArg`/`congrFun'` and
`simpLambda`
3. **`toHave`**: Convert back to `have` form
## Benchmark Results
### Benchmark 1: Chain with all variables used in body
| n | Before (simp) | Before (kernel) | After (simp) | After (kernel) |
|---|---------------|-----------------|--------------|----------------|
| 50 | 1.2ms | 32ms | 1.6ms | 4.4ms |
| 100 | 2.4ms | **225ms** | 3.5ms | **10ms** |
| 200 | 4.5ms | — | 8.4ms | 27ms |
| 500 | 11.7ms | — | 33.6ms | 128ms |
### Benchmark 3: Parallel declarations (simplified values)
| n | Before (simp) | Before (kernel) | After (simp) | After (kernel) |
|---|---------------|-----------------|--------------|----------------|
| 50 | 0.5ms | 24ms | 0.8ms | 1.8ms |
| 100 | 1.2ms | **169ms** | 1.8ms | **5.3ms** |
| 200 | 2.2ms | — | 3.9ms | 17ms |
| 500 | 5.9ms | — | 12.3ms | 93ms |
### Benchmark 5: Chain with single dependency
| n | Before (simp) | Before (kernel) | After (simp) | After (kernel) |
|---|---------------|-----------------|--------------|----------------|
| 100 | 1.6ms | 6.2ms | 1.8ms | 6.2ms |
| 200 | 2.8ms | 21.6ms | 4.4ms | 16.5ms |
| 500 | 7.3ms | **125ms** | 12.8ms | **72ms** |
Key observations:
- Kernel time is now **linear** in telescope depth (previously
quadratic)
- Simp time increases slightly due to the transformation overhead
- Total time (simp + kernel) is dramatically reduced for large
telescopes
- The improvement is most pronounced when the body depends on many
variables
## Trade-offs
- Proof sizes are larger (more congruence lemma applications)
- Simp time has ~1.5x overhead from the transformation
- For very small telescopes (n < 10), the overhead may not pay off
The optimization targets the critical path: kernel type-checking was the
bottleneck preventing scaling to realistic symbolic simulation
workloads.
This PR fixes a panic that occurred when a theorem had a docstring on an
auxiliary definition within a `where` clause.
Reproducer:
```lean
theorem foo : True := aux where /-- -/ aux := True.intro
```
The issue was that `asyncMayModify` used `.any` to check if a nested
declaration could have its extension state modified, which returned
`false` when the declaration wasn't yet in `asyncConsts`. Using `.all`
instead returns `true` for `none` (vacuously true), allowing
modification
of extension state for nested declarations that haven't been added to
`asyncConsts` yet.
Closes#11799🤖 Prepared with Claude Code
---------
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR fixes library suggestions to include private proof-valued
structure fields.
Private proof-valued structure fields (like `private size_keys' :
keys.size = values.size`) generate projections with `_private.*` mangled
names. These were being filtered out by `isDeniedPremise` because
`isInternalDetail` returns true for names starting with `_`.
The fix allows private names through by checking `!isPrivateName name`,
following the pattern from #11946. This enables `grind +suggestions` to
discover and use private proof-valued structure fields from the current
module.
Soon I would like to fix the semantics of `isInternalDetail`, as the
current behaviour is clearly wrong, but as there are many call sites, I
would like to get the behaviour of tactics correct first.
Also switches `currentFile` to use `wasOriginallyTheorem` instead of
matching on `.thmInfo`, which correctly identifies both theorems and
proof-valued projections.
🤖 Prepared with Claude Code
Co-authored-by: Claude <noreply@anthropic.com>
This PR adds a new `first_par` tactic combinator that runs multiple
tactics in parallel and returns the first successful result (cancelling
the others).
The `try?` tactic's `atomicSuggestions` step now uses `first_par` to try
three grind variants in parallel:
- `grind? +suggestions` - uses library suggestion engine
- `grind? +locals` - unfolds local definitions from current file
- `grind? +locals +suggestions` - combines both
This leverages `TacticM.parFirst` which already provides the "first
success wins" parallel execution with cancellation.
### Depends on
- [x] depends on: #11946🤖 Prepared with Claude Code
---------
Co-authored-by: Claude <noreply@anthropic.com>
This PR adds a `+locals` configuration option to the `simp`, `simp_all`,
and `dsimp` tactics that automatically adds all definitions from the
current file to unfold.
Example usage:
```lean
def foo (n : Nat) : Nat := n + 1
-- Without +locals, simp doesn't know about foo
example (n : Nat) : foo n = n + 1 := by simp -- fails
-- With +locals, simp can unfold foo
example (n : Nat) : foo n = n + 1 := by simp +locals -- succeeds
```
The implementation iterates over `env.constants.map₂` (which contains
constants defined in the current module) and adds definitions to unfold.
Instance definitions and internal details are filtered out.
**Note:** For local theorems, use `+suggestions` instead, which will
include relevant local theorems via the library suggestion engine.
🤖 Prepared with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude <noreply@anthropic.com>
This PR adds a `+locals` configuration option to the `grind` tactic that
automatically adds all definitions from the current file as e-match
theorems. This provides a convenient alternative to manually adding
`[local grind]` attributes to each definition. In the form `grind?
+locals`, it is also helpful for discovering which local declarations it
may be useful to add `[local grind]` attributes to.
Example usage:
```lean
def foo (n : Nat) : Nat := n + 1
-- Without +locals, grind doesn't know about foo
example (n : Nat) : foo n = n + 1 := by grind -- fails
-- With +locals, grind can use the equation
example (n : Nat) : foo n = n + 1 := by grind +locals -- succeeds
```
Instance definitions and internal details are filtered out.
🤖 Prepared with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude <noreply@anthropic.com>
This PR makes the external checker lean4checker available as the
existing `leanchecker` binary already known to elan, allowing for
out-of-the-box access to it.
---------
Co-authored-by: Kim Morrison <kim@tqft.net>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR filters deprecated lemmas from `exact?` and `rw?` suggestions.
Previously, both tactics would suggest deprecated lemmas, which could be
confusing for users since using the suggestion would trigger a
deprecation warning.
Now, lemmas marked with `@[deprecated]` are filtered out in the
`addImport` functions that populate the discrimination trees used by
these tactics.
**Example (before this PR):**
```lean
import Mathlib.Logic.Basic
example (h : ∃ n : Nat, n > 0) : True := by
choose (n : Nat) (hn : n > 0 + 0) using h
guard_hyp hn : n > 0 -- `rw?` would suggest `Eq.rec_eq_cast` which is deprecated
```
Zulip discussion:
https://leanprover.zulipchat.com/#narrow/channel/287929-mathlib4/topic/deprecated.20lemma.20from.20rw.3F/near/554106870🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
This PR improves the error message when `initialize` (or `opaque`) fails
to find an `Inhabited` or `Nonempty` instance.
**Before:**
```
failed to synthesize
Inhabited Foo
```
**After:**
```
failed to synthesize 'Inhabited' or 'Nonempty' instance for
Foo
If this type is defined using the 'structure' or 'inductive' command, you can try adding a 'deriving Nonempty' clause to it.
```
Prompted by
https://leanprover.zulipchat.com/#narrow/channel/270676-lean4/topic/initialize.20structure.20with.20IO.2ERef/near/564936030🤖 Prepared with Claude Code
---------
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>
