This PR fixes a CMake scoping bug that made `-DLEAN_VERSION_*` overrides
ineffective.
The version variables (`LEAN_VERSION_MAJOR`, `MINOR`, `PATCH`,
`IS_RELEASE`) were declared with plain `set()`, which creates normal
variables that shadow cache variables set by `-D` on the command line.
The fix changes them to `CACHE STRING ""` to match the existing
`LEAN_SPECIAL_VERSION_DESC` pattern.
However, `CACHE STRING ""` alone isn't sufficient because `project(LEAN
CXX C)` implicitly creates empty `LEAN_VERSION_{MAJOR,MINOR,PATCH}`
normal variables (CMake sets `<PROJECT>_VERSION_*` for the project
name). These shadow the cache values, so we `unset()` them after the
cache declarations to let `${VAR}` fall through to the cache.
Closes https://github.com/leanprover/lean4/issues/12681🤖 Prepared with Claude Code
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR deprecates `levelZero` in favor of `Level.zero` and `levelOne`
in favor of the new `Level.one`, and updates all usages throughout the
codebase. The `levelZero` alias was previously required for computed
field `data` to work, but this is no longer needed.
🤖 Prepared with Claude Code
This PR adds general projection lemmas for `ExceptConds` conjunction:
- `ExceptConds.and_elim_left`: `(x ∧ₑ y) ⊢ₑ x`
- `ExceptConds.and_elim_right`: `(x ∧ₑ y) ⊢ₑ y`
The existing `and_true`, `true_and`, `and_false`, `false_and` are
refactored as one-line corollaries.
Suggested by @sgraf812 in
https://github.com/leanprover-community/cslib/pull/376#discussion_r2066993469.
🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR fixes `@[implicit_reducible]` on well-founded recursive
definitions.
`addPreDefAttributes` sets WF-recursive definitions as `@[irreducible]`
by default, skipping this only when the user explicitly wrote
`@[reducible]` or `@[semireducible]`. It was missing
`@[instance_reducible]` and `@[implicit_reducible]`, causing those
attributes to be silently overridden.
Add `instance_reducible` and `implicit_reducible` to the check in
`src/Lean/Elab/PreDefinition/Mutual.lean` that guards against overriding
user-specified reducibility attributes, and add regression tests in
`tests/elab/wfirred.lean`.
## Example
```lean
-- Before fix: printed @[irreducible] def f : List Nat → Nat
-- After fix: printed @[implicit_reducible] def f : List Nat → Nat
@[instance_reducible] def f : ∀ _l : List Nat, Nat
| [] => 0
| [_x] => 1
| x :: y :: l => if h : x = y then f (x :: l) else f l + 2
termination_by l => sizeOf l
#print sig f
```
Fixes#12775
---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: nomeata <148037+nomeata@users.noreply.github.com>
This PR provides a `ForwardPatternModel` for string patterns and deduces
theorems and lawfulness instances from the corresponding results for
slice patterns.
This PR fixes an inconsistency in `getStuckMVar?` where the instance
argument to class projection functions and auxiliary parent projections
was not whnf-normalized before checking for stuck metavariables. Every
other case in `getStuckMVar?` (recursors, quotient recursors, `.proj`
nodes) normalizes the major argument via `whnf` before recursing — class
projection functions and aux parent projections were the exception.
This bug was identified by Matthew Jasper. When the instance parameter
to a class projection is not normalized, `getStuckMVar?` may fail to
detect stuck metavariables that would be revealed by whnf, or conversely
may report stuckness for expressions that would reduce to constructors.
This caused issues with `OfNat` and `Zero` at
`with_reducible_and_instances` transparency.
Note: PR #12701 (already merged) is also required to fix the original
Mathlib examples.
This PR adds `at` location syntax to the `cbv` tactic, matching the
interface of `simp at`. Previously `cbv` could only reduce the goal
target; now it supports `cbv at h`, `cbv at h |-`, and `cbv at *`.
`cbvGoal` is rewritten to use `Sym.preprocessMVar` followed by `cbvCore`
within a single `SymM` context, sharing the term table across all
hypotheses and the target. The old `cbvGoalCore` (which reduced one side
of an equation goal at a time) is replaced by a general approach that
reduces arbitrary goal types and hypothesis types, with special handling
for `True` targets and `False` hypotheses. `cbvDecideGoal` is updated to
use the extracted `cbvCore` as well.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
---------
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This PR adds a dedicated cbv simproc for `Decidable.decide` that
directly matches on `isTrue`/`isFalse` instances, producing simpler
proof terms and avoiding unnecessary unfolding through `Decidable.rec`.
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR generalizes `String.Slice.Pos.cast`, which turns an `s.Pos` into
a `t.Pos`, to no longer require `s = t`, but merely `s.copy = t.copy`.
This is a breaking change, but one that is easy to adapt to, by
replacing `proof` with `congrArg Slice.copy proof` where required.
This PR adds `deriving noncomputable instance Foo for Bar` syntax so
that delta-derived instances can be marked noncomputable. Previously,
when the underlying instance was noncomputable, `deriving instance`
would fail with an opaque async compilation error.
Now:
- `deriving noncomputable instance Foo for Bar` marks the generated
instance as noncomputable (using `addDecl` + `addNoncomputable` instead
of `addAndCompile`)
- `deriving instance Foo for Bar` pre-checks for noncomputable
dependencies and gives an actionable error with a "Try this:" suggestion
pointing to the noncomputable variant
- For handler-based deriving (inductives/structures), `noncomputable`
sets `isNoncomputable` on the scope
The `optDefDeriving` and `optDeriving` trailing parsers are updated with
`notSymbol "noncomputable"` to prevent them from stealing the parse of
`deriving noncomputable instance ...`.
🤖 Prepared with Claude Code
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR enables Lake to download artifacts from a remote cache service
on demand as part of a `lake build`. It also refactors much of the cache
API to be more type safe.
The newly documented `lake cache add` command loads input-to-output
mappings from a file and stores them in the cache with optional
information about which cache service and what scope they come from.
With this information, Lake can now download artifacts on demand during
a `lake build`.
The `lake cache get` command has also changed its default behavior to
download just the input-to-outputs mapping and then lazily fetch
artifacts from Reservoir as part of a `lake build`. The original eager
behavior can be forced via the new `--download-arts` option.
This PR using `StateT.run` rather than the "defeq abuse" of function
application. There remain many places where we still use function
application for `ReaderT`, but I've updated this in the touched files.
(To really solve this, we would make `StateT` irreducible, but that is
not happening here.)
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR adds a HACK comment to the transparency restriction in
`isNonTrivialRegular` (from
https://github.com/leanprover/lean4/pull/12650) so it's not forgotten.
🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR ensures `linter.all` disables `constructorNameAsVariable`.
The issue was discovered by @eric-wieser while investigating a quote4
issue.
This seems like an easy mistake to make when setting up a new linter,
and perhaps we need a better structure to make it easy to do the right
thing.
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR replaces the `isImplicitReducible` check with `Meta.isInstance`
in the `shouldInline` function within `inlineCandidate?`.
At the base phase, we skip inlining instances tagged with
`[inline]`/`[always_inline]`/`[inline_if_reduce]` because their local
functions will be lambda lifted during the base phase. The goal is to
keep instance code compact so the lambda lifter can extract
cheap-to-inline declarations. Inlining instances prematurely expands the
code and creates extra work for the lambda lifter — producing many
additional lambda-lifted closures.
The previous check used `isImplicitReducible`, which does not capture
the original intent: some `instanceReducible` declarations are not
instances. `Meta.isInstance` correctly targets only actual type class
instances. Although `Meta.isInstance` depends on the scoped extension
state, this is safe because `shouldInline` runs during LCNF compilation
at `addDecl` time — any instance referenced in the code was resolved
during elaboration when the scope was active, and LCNF compilation
occurs before the scope changes.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR changes the approach in `simpIteCbv` and `simpDIteCbv`, by
replacing call to `Decidable.decide`
with reducing and direct pattern matching on the `Decidable` instance
for `isTrue`/`isFalse`. This produces simpler proof terms.
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR adds pre-pass simprocs `simpOr` and `simpAnd` to the `cbv`
tactic that evaluate only the left argument of `Or`/`And` first,
short-circuiting when the result is determined without evaluating the
right side. Previously, `cbv` processed `Or`/`And` via congruence, which
always evaluated both arguments. For expressions like `decide (m < n ∨
expensive)`, when `m < n` is true, the expensive right side is now
skipped entirely.
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR adds a bitblasting circuit for `BitVec.cpop` with a
divide-and-conquer for a parallel-prefix-sum.
This is the [most efficient circuit we could
fine](https://docs.google.com/spreadsheets/d/1dJ5uUY4-eWIQmMjIui3H4U-wBxBxy-qYuqJZFZD1xvA/edit?usp=sharing),
after comparing with Kernighan's algorithm and with the intuitive
addition circuit.
---------
Co-authored-by: Henrik Böving <hargonix@gmail.com>
This PR provides injectivity lemmas for `List.getElem`, `List.getElem?`,
`List.getElem!` and `List.getD` as well as for `Option`. Note: This
introduces a breaking change, changing the signature of
`Option.getElem?_inj`.
This PR fixes `pp.fvars.anonymous` to display loose free variables as
`_fvar._` instead of `_` when the option is set to `false`. This was the
intended behavior in https://github.com/leanprover/lean4/pull/12688 but
the fix was committed locally and not pushed before that PR was merged.
🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR gives the `generate` function's "apply @Foo to Goal" trace nodes
their own trace sub-class `Meta.synthInstance.apply` instead of sharing
the parent `Meta.synthInstance` class.
This allows metaprograms that walk synthesis traces to distinguish
instance application attempts from other synthesis nodes by checking
`td.cls` rather than string-matching on the header text.
The new class is registered with `inherited := true`, so `set_option
trace.Meta.synthInstance true` continues to show these nodes.
Motivated by mathlib's `#defeq_abuse` diagnostic tactic
(https://github.com/leanprover-community/mathlib4/pull/35750) which
currently checks `headerStr.contains "apply"` to identify these nodes.
See
https://leanprover.zulipchat.com/#narrow/channel/113488-general/topic/backward.2EisDefEq.2ErespectTransparency🤖 Prepared with Claude Code
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR adds a `pp.fvars.anonymous` option (default `true`) that
controls the display of loose free variables (fvars not in the local
context).
- When `true` (default), loose fvars display their internal name like
`_fvar.42`
- When `false`, they display as `_fvar._`
This is analogous to `pp.mvars.anonymous` for metavariables. It's useful
for stabilizing output in `#guard_msgs` when messages contain fvar IDs
that vary between runs — for example, in diagnostic tools that report
`isDefEq` failures from trace output where the local context is not
available.
🤖 Prepared with Claude Code
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR fixes a gap in how `@[implicit_reducible]` is assigned to parent
projections during structure elaboration.
When `class C extends P₁, P₂` has diamond inheritance, some ancestor
structures become constructor subobject fields even though they aren't
direct parents. For example, in `Monoid extends Semigroup, MulOneClass`,
`One` becomes a constructor subobject of `Monoid` — its field `one`
doesn't overlap with `Semigroup`'s fields, and `inSubobject?` is `none`
during `MulOneClass` flattening.
`mkProjections` creates the projection `Monoid.toOne` but defers
reducibility to `addParentInstances` (guarded by `if !instImplicit`).
However, `addParentInstances` only processes direct parents from the
`extends` clause. Grandparent subobject projections fall through the gap
and stay `semireducible`.
This causes defeq failures when `backward.isDefEq.respectTransparency`
is enabled (#12179): at `.instances` transparency, the semireducible
grandparent projection can't unfold, so two paths to the same ancestor
structure aren't recognized as definitionally equal.
Fix: before `addParentInstances`, iterate over all `.subobject` fields
and set `implicitReducible` on those whose parent is a class.
🤖 Prepared with Claude Code
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR marks `levelZero` and `Level.ofNat` as `@[implicit_reducible]`
so that `Level.ofNat 0 =?= Level.zero` succeeds when the definitional
equality checker respects transparency annotations. Without this,
coercions between structures with implicit `Level` parameters fail, as
reported by @FLDutchmann on
[Zulip](https://leanprover.zulipchat.com/#narrow/channel/113488-general/topic/backward.2EisDefEq.2ErespectTransparency/near/576131374).
🤖 Prepared with Claude Code
---------
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
This PR relates `String.split` to `List.splitOn` and `List.splitOnP`,
provided that we are splitting by a character or character predicate.
Also included: some more lemmas about `List.splitOn`, and a refactor of
the generic `split` verification to get rid of the awkward `SlicesFrom`
constuct.
This PR ensures the compiler extracts `Array`/`ByteArray`/`FloatArray`
literals as one big closed term to avoid quadratic overhead at closed
term initialization time.
This PR fixes a bug in `Meta.zetaReduce` where `have` expressions were
not being zeta reduced. It also adds a feature where applications of
local functions are beta reduced, and another where zeta-delta reduction
can be disabled. These are all controllable by flags:
- `zetaDelta` (default: true) enables unfolding local definitions
- `zetaHave` (default: true) enables zeta reducing `have` expressions
- `beta` (default: true) enables beta reducing applications of local
definitions
Closes#10850
This PR changes the order of implicit parameters `α` and `ps` such that
`α` consistently comes before `ps` in `PostCond.noThrow`,
`PostCond.mayThrow`, `PostCond.entails`, `PostCond.and`, `PostCond.imp`
and theorems.
This PR ports the simple ground expression extraction pass from IR to
LCNF.
I locally confirmed that this produces no diff between stage1/stage2 at
the C level (apart from the
changed compiler files) so this should essentially be binary equivalent.
This PR upstreams `List.splitOn` and `List.splitOnP` from
Batteries/mathlib.
The function `splitOnP.go` is factored out to `splitOnPPrepend`, because
it is useful to state induction hypotheses in terms of
`splitOnPPrepend`.
This PR ports the expand reset/reuse pass from IR to LCNF. In addition
it prevents exponential code generation unlike the old one. This results
in a ~15% decrease in binary size and slight speedups across the board.
The change also removes the "is this reset actually used" syntactic
approximation as the previous passes guarantee (at the moment) that all
uses are in the continuation and will thus be caught by this.
This PR enables the module system, in cooperation with the linker, to
separate meta and non-meta code in native binaries. In particular, this
ensures tactics merely used in proofs do not make it into the final
binary. A simple example using `meta import Lean` has its binary size
reduced from 130MB to 1.7MB.
# Breaking change
`importModules (loadExts := true)` must now be preceded by
`enableInitializersExecution`. This was always the case for correct
importing but is now enforced and checked eagerly.
This PR reverts commit 9b7a8eb7c8. After
some more contemplation on
the implications of these changes I think this is not the direction we
want to move into.
This PR sets up the new integrated test/bench suite. It then migrates
all benchmarks and some related tests to the new suite. There's also
some documentation and some linting.
For now, a lot of the old tests are left alone so this PR doesn't become
even larger than it already is. Eventually, all tests should be migrated
to the new suite though so there isn't a confusing mix of two systems.
This PR fixes an issue where `mutual public structure` would have a
private constructor. The fix copies the fix from #11940.
Closes#10067. Also recloses duplicate issue #11116 (its test case is
added to the test suite).
This PR adds several useful lemmas for `List`, `Array` and `Vector`
whenever they were missing, improving API coverage and consistency among
these types.
- `size_singleton`/`sum_singleton`/`sum_push`
-
`foldlM_toArray`/`foldlM_toList`/`foldl_toArray`/`foldl_toList`/`foldrM_toArray`/`foldrM_toList`/`foldr_toList`
- `toArray_toList`
- `foldl_eq_apply_foldr`/`foldr_eq_apply_foldl`, `foldr_eq_foldl`:
relates `foldl` and `foldr` for associative operations with identity
- `sum_eq_foldl`: relates sum to `foldl` for associative operations with
identity
- `Perm.pairwise_iff`/`Perm.pairwise`: pairwise properties are preserved
under permutations of arrays
This PR provides `WellFounded.partialExtrinsicFix`, which makes it
possible to implement and verify partially terminating functions, safely
building on top of the seemingly less general `extrinsicFix` (which is
now called `totalExtrinsicFix`). A proof of termination is only
necessary in order to formally verify the behavior of
`partialExtrinsicFix`.
