- Cache now indexes by (ele, r) pair using obj_pair_map
- Remove eval() function; operator()(ele, r) handles all cases
- Rewrite simplify_ite_rec with path vector of signed conditions
- Add range-based simplification: (lo <= x, false) + (x <= hi, false)
eliminates ite(x = v, t, e) when v is outside [lo, hi]
- Add is_itos case in derive_to_re: guards on n >= 0, digit range,
and first character match
- Port is_reverse normalization (previous commit)
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Instead of treating reverse(r) as stuck (returning symbolic mk_derivative),
normalize it by pushing reverse inward through the regex structure, then
compute the derivative of the normalized result. Mirrors mk_re_reverse logic.
Handles: concat, union, intersection, diff, ite, opt, complement, star,
plus, loop, to_re (string literals, units, concats), and symmetric cases.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Implement a new seq::derive class (seq_derive.h/cpp) that computes
symbolic derivatives of regular expressions using ITE-trees, based on
the RE# approach (Varatalu, Veanes, Ernits - POPL 2025).
Key features:
- Two-argument operator()(ele, r): computes derivative of regex r w.r.t.
element ele (concrete character or de Bruijn variable for symbolic mode)
- ACI canonicalization (flatten, stable_sort, dedup) for union/intersection
- ITE-tree combinators for binary/unary operations
- Info-based nullability with recursive fallback
- Complement absorption rules
- Depth-bounded recursion to prevent stack overflow
Integration with seq_rewriter:
- mk_derivative(ele, r) and mk_derivative(r) now delegate to m_derive
- Removed dead mk_derivative_rec function
- Added ITE hoisting in mk_re_star, mk_re_concat, mk_re_union0,
mk_re_inter0, mk_re_complement
- Added depth limiting in Antimirov derivative helpers
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
Implements the algorithm of Eq(p,q) = Empty(p XOR q)' using a union-find
driven bisimulation closure (per the CAV'26 ERE paper).
### What's added
* **New primitive OP_RE_XOR (re.xor)** wired through seq_decl_plugin:
parser signature, info propagation (nullable, min_length), and
pretty-printer.
* **seq_rewriter**: structural XOR rewrites ( XOR r = empty, XOR empty =
r, ull XOR r = comp(r), comp/comp absorption, complement push, AC
normalisation), nullability (Null(p XOR q) = Null(p) != Null(q)),
derivative (D_a(p XOR q) = D_a(p) XOR D_a(q)), reverse, antimirov
derivative, and `check_deriv_normal_form` coverage.
* **New class seq::regex_bisim** in
`src/ast/rewriter/seq_regex_bisim.{h,cpp}` to keep the bisim logic out
of the already-large `seq_rewriter.cpp`. Uses `basic_union_find` from
`util/union_find.h`, an `obj_map` for the node assignment, and a
50000-step bound (returns `l_undef` on overrun).
* **Integration** in `seq_rewriter::reduce_re_eq` (with a re-entry
guard) and in `seq_regex::propagate_eq` / `propagate_ne` for ground
regexes; on `l_undef` we fall back to the existing axiomatisation.
* **`sls_seq_plugin`**: extend `OP_RE_DIFF` switch arms to also cover
`OP_RE_XOR`.
### Validation
* Full release build with MSVC + Ninja.
* `./test-z3 /a` -- 89/89 tests passing.
* `./test-z3 /seq smt2print_parse` -- PASS.
* Smoke tests with `(a|b)*` vs `(a*b*)*` (equal) and `a*` vs `(a|b)*`
(not equal) return the expected `sat`/`unsat` quickly.
---------
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
`seq_rewriter.cpp` was missing several regex-concat normalizations
around `re.all` (`Σ*`), causing avoidable growth and missed
simplifications. This update fills the four gaps: nullable absorption,
guarded union distribution, intersection suffix elimination, and
nested-star collapse.
- **Nullable/full-seq absorption (A1)**
- Generalizes `Σ*·R → Σ*` and `R·Σ* → Σ*` beyond `Σ*·Σ*`.
- Applies when `R` is interpreted, nullable, and has `min_length = 0`.
- **Guarded distribution over union (A2)**
- Adds `Σ*·(R1 ∪ R2)` distribution when at least one arm is already
`Σ*`-headed.
- Rebuilds via normalized union so the redundant arm collapses to `Σ*`.
- **Intersection + full-seq tail elimination (A3)**
- Adds `(R1 ∩ … ∩ Rn)·Σ* → (R1 ∩ … ∩ Rn)` when every intersection leaf
already ends in `Σ*`.
- **Nested star concat collapse (A4)**
- Adds `R*·(R*·X) → R*·X`, covering non-adjacent star patterns not
handled by the prior adjacent-only rewrite.
```cpp
if (re().is_full_seq(a) && accepts_empty_word(b)) result = a; // A1
if (re().is_full_seq(a) && re().is_union(b, u1, u2) && ...) ... // A2
if (re().is_intersection(a, u1, u2) && re().is_full_seq(b) && ...) result=a; // A3
if (re().is_star(a, a1) && re().is_concat(b, b1, b2) && re().is_star(b1,b3) && a1==b3) result=b; // A4
```
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Z3 could return `sat` for an unsatisfiable QF_ABV formula equating two
store chains over distinct constant arrays. The rewrite path for array
equalities was missing a necessary base-value constraint in
finite-domain cases where stores cannot cover all indices.
- **Root cause**
- In `array_rewriter::mk_eq_core`, equality rewriting for nested stores
over const-array bases did not enforce equality of the underlying const
values when the index domain size exceeds the number of updated indices.
- **Rewriter fix**
- Added a sound rewrite branch for:
- `store* ((as const ...) v)` vs `store* ((as const ...) w)`
- When `|domain| > (#stores_lhs + #stores_rhs)`, rewrite now includes:
- select equalities for touched indices (existing behavior)
- **and** base-value equality `v = w` (new requirement)
- This prevents spurious models where only updated indices are
constrained.
- **Regression coverage**
- Added a focused regression in `src/test/mod_factor.cpp` that asserts
`unsat` for a minimized constant-array/store-chain BV case with
`(distinct x y)` and one store per side.
```cpp
(assert (distinct x y))
(assert (= (store A0 i0 e0) (store A1 i1 e1)))
(check-sat) ; expected: unsat
```
---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
The arith rewriter now recognizes that x * (x + 1) >= 0 for all
integers, since no integer lies strictly between -1 and 0.
Two changes:
1. is_non_negative: detect products where unpaired factors are
consecutive integer expressions (differ by exactly 1), handling
both +1 and -1 offsets and n-ary additions
2. is_separated: return true for (>= non_negative_mul 0), restricted
to multiplication expressions to avoid disrupting other theories
Also adds regression tests for the new simplification.
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
* Initial plan
* Refactor der.cpp to use structured bindings for expression/index pairs
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
* Fix comment to refer to 'e' instead of 't' after structured binding refactor
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
* Fix implicit conversion warnings: use UINT_MAX instead of -1 for unsigned variables
Replace implicit conversion from negative literal to unsigned type
with explicit UINT_MAX constant to eliminate compiler warnings.
Fixed 10 instances across 6 files:
- src/ast/rewriter/bv_rewriter.cpp: 1 instance
- src/ast/sls/sls_bv_tracker.h: 2 instances
- src/math/lp/dioph_eq.cpp: 3 instances
- src/math/lp/lp_primal_core_solver.h: 2 instances
- src/muz/transforms/dl_mk_array_instantiation.cpp: 1 instance
- src/muz/transforms/dl_mk_synchronize.cpp: 1 instance
These changes preserve the exact same runtime behavior (UINT_MAX
equals the wrapped value of -1 for unsigned types) while making
the code more explicit and warning-free.
* Update bv_rewriter.cpp
---------
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
* Initial plan
* Refactor mk_and and mk_app to use std::span
- Made mk_and(unsigned num_args, expr * const * args) private
- Added new public mk_and(std::span<expr* const> args) method
- Added new public mk_app(family_id fid, decl_kind k, std::span<expr* const> args) method
- Updated all convenience overloads to use std::span version
- Updated all external call sites to use the new std::span API
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
* Fix remaining test files to use std::span API
- Updated src/test/sorting_network.cpp
- Updated src/test/ho_matcher.cpp with explicit cast to resolve ambiguity
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
* Revert overlapping changes superseded by PR #8286
Reverted 30 files to match the state from PR #8286 (commit ebc0688) which refactored mk_and/mk_or call sites to use vector overloads. This supersedes the std::span changes in those files.
Retained std::span changes in files unique to this PR:
- Core API changes (ast.h, ast.cpp)
- Files not affected by PR #8286 (api_context.cpp, ast_util.cpp, bool_rewriter.h, datatype_rewriter.cpp, dom_simplifier.cpp, factor_rewriter.cpp, pb2bv_rewriter.cpp, quant_hoist.cpp, spacer_cluster_util.cpp, sortmax.cpp, array_axioms.cpp, smtfd_solver.cpp, goal.cpp, ho_matcher.cpp, qe_arith.cpp, sorting_network.cpp)
- Special case in hnf.cpp where both PRs modified different lines
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
* Initial plan
* Refactor mk_and and mk_or call sites to use overloaded methods
Changed 130 call sites across 64 files to use vector overloads directly instead of manually passing .size() and .data()/.c_ptr()
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
* Revert mk_or changes for ptr_buffer/ptr_vector (no overload exists in ast_util.h)
* Fix compilation errors from mk_and/mk_or refactoring
Fixed type mismatches by:
- Removing m parameter for expr_ref_vector (ast_util.h has mk_and/mk_or(expr_ref_vector) overloads)
- Reverting changes for ref_buffer types (no overload exists in ast_util.h, only in ast.h for m.mk_and)
- Verified build succeeds and Z3 works correctly
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
* Fix test files to use correct mk_and/mk_or overloads
Changed test/doc.cpp and test/udoc_relation.cpp to use mk_and(expr_ref_vector) and mk_or(expr_ref_vector) without m parameter
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
* Initial plan
* Update z3 codebase to use std::string_view (except z3++.h)
- Updated params.cpp/h to use string_view internally for parameter descriptions
- Updated trace.h/cpp to accept string_view for trace tag functions
- Updated hash.h/cpp to use string_view for string_hash function
- Updated all callers of string_hash to use string_view
- Properly handled nullptr to empty string_view conversions
- All tests passing
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
* Add missing string_view includes to headers
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
* Initial plan
* Migrate iterator-based for loops to range-based for loops in 11 files
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
* Fix compilation error in aig_exporter.cpp - use correct iterator API
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
* Revert changes to z3++.h as requested
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
* somewhaat failed attempt at declaring subterm predicate
I can't really figure out how to link the smt parser to the rest of the
machinenery, so I will stop here and try from the other side. I'll start
implmenting the logic and see if it brings me back to the parser.
* initial logic implmentation
Very primitive, but I don't like have that much work uncommitted.
* parser implementation
* more theory
* Working base
* subterm reflexivity
* a few optimization
Skip adding obvious equalities or disequality
* removed some optimisations
* better handling of backtracking
* stupid segfault
Add m_subterm to the trail
* Update src/smt/theory_datatype.h
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
* Update src/ast/rewriter/datatype_rewriter.cpp
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
* Update src/smt/theory_datatype.cpp
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
* Update src/smt/theory_datatype.cpp
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
* Update src/smt/theory_datatype.cpp
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
* review
* forgot to update `iterate_subterm`'s signature
* fix iterator segfault
* Remove duplicate include statement
Removed duplicate include of 'theory_datatype.h'.
* Replace 'optional' with 'std::option' in datatype_decl_plugin.h
* Add is_subterm_predicate matcher to datatype_decl_plugin
* Change std::option to std::optional for m_subterm
* Update pdecl.h
* Change has_subterm to use has_value method
* Update pdecl.cpp
---------
Co-authored-by: Nikolaj Bjorner <nbjorner@microsoft.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
* Initial plan
* Convert plain enums to enum class in EUF module
- Convert eq_status in euf::ac_plugin to enum class
- Convert undo_kind in euf::ac_plugin to enum class
- Convert undo_t in euf::arith_plugin to enum class
- Convert to_merge_t in euf::egraph to enum class
- Update all usage sites to use scoped enum syntax
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
* Convert more plain enums to enum class
- Convert state enum in substitution class
- Convert instruction enum in generic_model_converter class
- Convert eq_type enum in bit2int class
- Update all usage sites to use scoped enum syntax
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
---------
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
default behavior is conservative: if the body of a recursive function contains uninterpreted variables they are not rewritten.
Model evaluation will bind values to uninterpreted variables so the filter should not apply here.
