This PR adds support for correctly handling computations on fields in
`casesOn` for inductive predicates that support large elimination. In
any such predicate, the only relevant fields allowed are those that are
also used as an index, in which case we can find the supplied index and
use that term instead.
This PR improves support for `Fin n` in `grind cutsat` when `n` is not a
numeral. For example, the following goals can now be solved
automatically:
```lean
example (p d : Nat) (n : Fin (p + 1))
: 2 ≤ p → p ≤ d + 1 → d = 1 → n = 0 ∨ n = 1 ∨ n = 2 := by
grind
example (s : Nat) (i j : Fin (s + 1)) (hn : i ≠ j) (hl : ¬i < j) : j < i := by
grind
example {n : Nat} (j : Fin (n + 1)) : j ≤ j := by
grind
example {n : Nat} (x y : Fin ((n + 1) + 1)) (h₂ : ¬x = y) (h : ¬x < y) : y < x := by
grind
```
This PR adds `@[expose]` to `Lean.ParserState.setPos`. This makes it
possible to prove in-boundedness for a state produced by `setPos` for
functions like `next'` and `get'` without needing to `import all`.
This came up while porting Lake to the module system (#9749).
This PR changes the handling of overapplied constructors when lowering
LCNF to IR from a (slightly implicit) assertion failure to producing
`unreachable`. Transformations on inlined unreachable code can produce
constructor applications with additional arguments.
In the old compiler, these additional arguments were silently ignored,
but it seems more sensible to replace them with `unreachable`, just in
case they arise due to a compiler error.
Fixes#9937.
This PR derives `BEq` and `Hashable` for `Lean.Import`. Lake already did
this later, but it now done when defining `Import`.
Doing this in Lake became problematic when porting it to the module
system (#9749).
The current reuse analysis is greedy in that every function attempts to
reuse a value. However, this means that if the last use is an owned
argument, it will be `inc`'d prior to this last use, in order to prevent
reuse from happening in the callee. In many cases, it makes more sense
to give the callee the chance to reuse it instead. The benchmark results
indicate that this is a much better default.
This PR improves support for nonlinear `/` and `%` in `grind cutsat`.
For example, given `a / b`, if `cutsat` discovers that `b = 2`, it now
propagates that `a / b = b / 2`. This PR is similar to #9996, but for
`/` and `%`. Example:
```lean
example (a b c d : Nat)
: b > 1 → d = 1 → b ≤ d + 1 → a % b = 1 → a = 2 * c → False := by
grind
```
This PR fixes a bug in `#eval` where clicking on the evaluated
expression could show errors in the Infoview. This was caused by `#eval`
not saving the temporary environment that is used when elaborating the
expression.
This PR improves support for nonlinear monomials in `grind cutsat`. For
example, given a monomial `a * b`, if `cutsat` discovers that `a = 2`,
it now propagates that `a * b = 2 * b`.
Recall that nonlinear monomials like `a * b` are treated as variables in
`cutsat`, a procedure designed for linear integer arithmetic.
Example:
```lean
example (a : Nat) (ha : a < 8) (b c : Nat) : 2 ≤ b → c = 1 → b ≤ c + 1 → a * b < 8 * b := by
grind
example (x y z w : Int) : z * x * y = 4 → x = z + w → z = 1 → w = 2 → False := by
grind
```
This PR registers a parser alias for `Lean.Parser.Command.visibility`.
This avoids having to import `Lean.Parser.Command` in simple command
macros that use visibilities.
This PR makes `IsPreorder`, `IsPartialOrder`, `IsLinearPreorder` and
`IsLinearOrder` extend `BEq` and `Ord` as appropriate, adds the
`LawfulOrderBEq` and `LawfulOrderOrd` typeclasses relating `BEq` and
`Ord` to `LE`, and adds many lemmas and instances.
Note: This PR contains a refactoring where `Init.Data.Ord` is moved to
`Init.Data.Ord.Basic`. If I added `Init.Data.Ord` simply importing all
submodules, git would not be able to determine that `Init.Data.Ord` was
renamed to `Init.Data.Ord.Basic`. This could lead to unnecessary merge
conflicts in the future. Hence, I chose the name `Init.Data.OrdRoot`
instead of `Init.Data.Ord` temporarily. After this PR, I will rename
this module back to `Init.Data.Ord` in a separate PR.
(This is a copy of #9430: I will not touch that PR because it currently
allows to debug a CI problem and pushing commits might break the
reproducibility.)
This PR fixes an issue when running Mathlib's `FintypeCat` as code,
where an erased type former is passed to a polymorphic function. We were
lowering the arrow type to`object`, which conflicts with the runtime
representation of an erased value as a tagged scalar.
This PR modifies the generation of induction and partial correctness
lemmas for `mutual` blocks defined via `partial_fixpoint`. Additionally,
the generation of lattice-theoretic induction principles of functions
via `mutual` blocks is modified for consistency with `partial_fixpoint`.
The lemmas now come in two variants:
1. A conjunction variant that combines conclusions for all elements of
the mutual block. This is generated only for the first function inside
of the mutual block.
2. Projected variants for each function separately
## Example 1
```lean4
axiom A : Type
axiom B : Type
axiom A.toB : A → B
axiom B.toA : B → A
mutual
noncomputable def f : A := g.toA
partial_fixpoint
noncomputable def g : B := f.toB
partial_fixpoint
end
```
Generated `fixpoint_induct` lemmas:
```lean4
f.fixpoint_induct (motive_1 : A → Prop) (motive_2 : B → Prop) (adm_1 : admissible motive_1)
(adm_2 : admissible motive_2) (h_1 : ∀ (g : B), motive_2 g → motive_1 g.toA)
(h_2 : ∀ (f : A), motive_1 f → motive_2 f.toB) : motive_1 f
g.fixpoint_induct (motive_1 : A → Prop) (motive_2 : B → Prop) (adm_1 : admissible motive_1)
(adm_2 : admissible motive_2) (h_1 : ∀ (g : B), motive_2 g → motive_1 g.toA)
(h_2 : ∀ (f : A), motive_1 f → motive_2 f.toB) : motive_2 g
```
Mutual (conjunction) variant:
```lean4
f.mutual_fixpoint_induct (motive_1 : A → Prop) (motive_2 : B → Prop) (adm_1 : admissible motive_1) (adm_2 : admissible motive_2)
(h_1 : ∀ (g : B), motive_2 g → motive_1 g.toA) (h_2 : ∀ (f : A), motive_1 f → motive_2 f.toB) :
motive_1 f ∧ motive_2 g
```
## Example 2
```lean4
mutual
def f (n : Nat) : Option Nat :=
g (n + 1)
partial_fixpoint
def g (n : Nat) : Option Nat :=
if n = 0 then .none else f (n + 1)
partial_fixpoint
end
```
Generated `partial_correctness` lemmas (in a projected variant):
```lean4
f.partial_correctness (motive_1 motive_2 : Nat → Nat → Prop)
(h_1 :
∀ (g : Nat → Option Nat),
(∀ (n r : Nat), g n = some r → motive_2 n r) → ∀ (n r : Nat), g (n + 1) = some r → motive_1 n r)
(h_2 :
∀ (f : Nat → Option Nat),
(∀ (n r : Nat), f n = some r → motive_1 n r) →
∀ (n r : Nat), (if n = 0 then none else f (n + 1)) = some r → motive_2 n r)
(n r✝ : Nat) : f n = some r✝ → motive_1 n r✝
g.partial_correctness (motive_1 motive_2 : Nat → Nat → Prop)
(h_1 :
∀ (g : Nat → Option Nat),
(∀ (n r : Nat), g n = some r → motive_2 n r) → ∀ (n r : Nat), g (n + 1) = some r → motive_1 n r)
(h_2 :
∀ (f : Nat → Option Nat),
(∀ (n r : Nat), f n = some r → motive_1 n r) →
∀ (n r : Nat), (if n = 0 then none else f (n + 1)) = some r → motive_2 n r)
(n r✝ : Nat) : g n = some r✝ → motive_2 n r✝
```
Mutual (conjunction) variant:
```
f.mutual_partial_correctness (motive_1 motive_2 : Nat → Nat → Prop)
(h_1 :
∀ (g : Nat → Option Nat),
(∀ (n r : Nat), g n = some r → motive_2 n r) → ∀ (n r : Nat), g (n + 1) = some r → motive_1 n r)
(h_2 :
∀ (f : Nat → Option Nat),
(∀ (n r : Nat), f n = some r → motive_1 n r) →
∀ (n r : Nat), (if n = 0 then none else f (n + 1)) = some r → motive_2 n r) :
(∀ (n r : Nat), f n = some r → motive_1 n r) ∧ ∀ (n r : Nat), g n = some r → motive_2 n r
```
This PR modifies `intro` to create tactic info localized to each
hypothesis, making it possible to see how `intro` works
variable-by-variable. Additionally:
- The tactic supports `intro rfl` to introduce an equality and
immediately substitute it, like `rintro rfl` (recall: the `rfl` pattern
is like doing `intro h; subst h`). The `rintro` tactic can also now
support `HEq` in `rfl` patterns if `eq_of_heq` applies.
- In `intro (h : t)`, elaboration of `t` is interleaved with unification
with the type of `h`, which prevents default instances from causing
unification to fail.
- Tactics that change types of hypotheses (including `intro (h : t)`,
`delta`, `dsimp`) now update the local instance cache.
In `intro x y z`, tactic info ranges are `intro x`, `y`, and `z`. The
reason for including `intro` with `x` is to make sure the info range is
"monotonic" while adding the first argument to `intro`.
This PR cleans up `optParam`/`autoParam`/etc. annotations before
elaborating definition bodies, theorem bodies, `fun` bodies, and `let`
function bodies. Both `variable`s and binders in declaration headers are
supported.
There are no changes to `inductive`/`structure`/`axiom`/etc. processing,
just `def`/`theorem`/`example`/`instance`.
This PR ensures that equations in the `grind cutsat` module are
maintained in solved form. That is, given an equation `a*x + p = 0` used
to eliminate `x`, the linear polynomial `p` must not contain other
eliminated variables. Before this PR, equations were maintained in
triangular form. We are going to use the solved form to linearize
nonlinear terms.
This PR removes the option `grind +ringNull`. It provided an alternative
proof term construction for the `grind ring` module, but it was less
effective than the default proof construction mode and had effectively
become dead code.
This PR also optimizes semiring normalization proof terms using the
infrastructure added in #9946.
**Remark:** After updating stage0, we can remove several background
theorems from the `Init/Grind` folder.
This PR optimizes the proof terms produced by `grind linarith`. It is
similar to #9945, but for the `linarith` module in `grind`.
It removes unused entries from the context objects when generating the
final proof, significantly reducing the amount of junk in the resulting
terms.
This PR optimizes the proof terms produced by `grind cutsat`. It removes
unused entries from the context objects when generating the final proof,
significantly reducing the amount of junk in the resulting terms.
Example:
```lean
/--
trace: [grind.debug.proof] fun h h_1 h_2 h_3 h_4 h_5 h_6 h_7 h_8 =>
let ctx := RArray.leaf (f 2);
let p_1 := Poly.add 1 0 (Poly.num 0);
let p_2 := Poly.add (-1) 0 (Poly.num 1);
let p_3 := Poly.num 1;
le_unsat ctx p_3 (eagerReduce (Eq.refl true)) (le_combine ctx p_2 p_1 p_3 (eagerReduce (Eq.refl true)) h_8 h_1)
-/
#guard_msgs in -- Context should contain only `f 2`
open Lean Int Linear in
set_option trace.grind.debug.proof true in
example (f : Nat → Int) :
f 1 <= 0 → f 2 <= 0 → f 3 <= 0 → f 4 <= 0 → f 5 <= 0 →
f 6 <= 0 → f 7 <= 0 → f 8 <= 0 → -1 * f 2 + 1 <= 0 → False := by
grind
```
This PR expands `mvcgen using invariants | $n => $t` to `mvcgen; case
inv<$n> => exact $t` to avoid MVar instantiation mishaps observable in
the test case for #9581.
Closes#9581.
This PR implements extended `induction`-inspired syntax for `mvcgen`,
allowing optional `using invariants` and `with` sections.
```lean
mvcgen
using invariants
| 1 => Invariant.withEarlyReturn
(onReturn := fun ret seen => ⌜ret = false ∧ ¬l.Nodup⌝)
(onContinue := fun traversalState seen =>
⌜(∀ x, x ∈ seen ↔ x ∈ traversalState.prefix) ∧ traversalState.prefix.Nodup⌝)
with mleave -- mleave is a no-op here, but we are just testing the grammar
| vc1 => grind
| vc2 => grind
| vc3 => grind
| vc4 => grind
| vc5 => grind
```
This PR guards the `Std.Tactic.Do.MGoalEntails` delaborator by a check
ensuring that there are at least 3 arguments present, preventing
potential panics.
