This file contains a summary of important user-visible changes.
New Features
- API: New API function
Solver::mkFloatingPoint(const Term& sign, const Term& exp, const Term& sig)
, returns a floating-point value from the three IEEE-754 bit-vector value components. - Support for timeout cores
- API: New API function
Solver::getTimeoutCore()
when applicable returns a subset of the current assertions that cause the solver to timeout without a provided timeout (option--timeout-core-timeout
). - SMT-LIB: New command
(get-timeout-core)
which invokes the above method.
- API: New API function
- A new (hand-written) parser is available and enabled by default.
- Note the previous parser can be enabled using command line options
--no-flex-parser --no-stdin-input-per-line
. These options will be available until version 1.1 is released.
- Note the previous parser can be enabled using command line options
New Features
- Support for the theory of (prime-order) finite fields:
- Sorts are created with
- C++:
Solver::makeFiniteFieldSort
- SMT-LIB:
(_ FiniteField P)
for prime orderP
- C++:
- Constants are created with
- C++:
Solver::makeFiniteFieldElem
- SMT-LIB:
(as ffN F)
for integerN
and field sortF
- C++:
- The operators are multiplication, addition and negation
- C++: kinds
FF_MUL
,FF_ADD
, andFF_NEG
- SMT-LIB: operators
ff.mul
,ff.add
, andff.neg
- C++: kinds
- The only predicate is equality
- Sorts are created with
New Features
- API: New API function
Solver::getVersion()
, returns a string representation of the solver version. - Support for bit-vector overflow detection operators:
BITVECTOR_UADDO
unsigned addition overflow detectionBITVECTOR_SADDO
signed addition overflow detectionBITVECTOR_UMULO
unsigned multiplication overflow detectionBITVECTOR_SMULO
signed multiplication overflow detectionBITVECTOR_USUBO
unsigned subtraction overflow detectionBITVECTOR_SSUBO
signed subtraction overflow detectionBITVECTOR_SDIVO
signed division overflow detection
- Support for Web Assembly compilation using Emscripten.
Changes
- The (non-standard) operators
BITVECTOR_TO_NAT
andINT_TO_BITVECTOR
now belong to the UF theory. A logic that includes UF is required to use them. - The sort for (non-standard) bit-vector operators
BITVECTOR_REDAND
andBITVECTOR_REDOR
is now(_ BitVec 1)
(was Boolean), following the definition of reduction operators in Verilog (their origin). - Reenable functionality that allows
(get-model)
commands after answeringunknown
when:produce-models
is set totrue
. Note that there is no guarantee that building a model succeeds in this case.
Changes
- API: Previously, it was not possible to share Sort, Term, Op, Grammar and datatype objects between Solver instances. This is now allowed for solvers that belong to the same thread.
New Features
- Support for cross-compiling an ARM binary of cvc5 on x86 macOS.
- Support for declaring oracle functions in the API via the method
declareOracleFun
. This allows users to declare functions whose semantics are associated with a provided executable implementation.
Changes
- Removed support for non-standard
declare-funs
,declare-consts
, anddeclare-sorts
commands. - The kind for integer constants is now
CONST_INTEGER
, while real constants continue to have kindCONST_RATIONAL
. - Type rules for (dis)equality and if-then-else no longer allow mixing
integers and reals. Type rules for other operators like
APPLY_UF
now require their arguments to match the type of the function being applied, and do not assume integer/real subtyping. - The API method
mkTuple
no longer supports casting integers to reals when constructing tuples.
Website: https://cvc5.github.io
Documentation: https://cvc5.github.io/docs
System Description
- cvc5: A Versatile and Industrial-Strength SMT Solver.
Barbosa H., Barrett C., Brain M., Kremer G., Lachnitt H., Mann M., Mohamed A., Mohamed M., Niemetz A., Nötzli A., Ozdemir A., Preiner M., Reynolds A., Sheng Y., Tinelli C., and Zohar Y., TACAS 2022.
New Features
-
Streamlined C++ API
- Documentation: https://cvc5.github.io/docs/latest/api/cpp/cpp.html
-
Two new Python language bindings
- Base module: Feature complete with C++ API
- Pythonic module: A pythonic wrapper around the base module
- Documentation: https://cvc5.github.io/docs/latest/api/python/python.html
-
New Java language bindings
- Documentation: https://cvc5.github.io/docs/latest/api/java/java.html
-
Theory of Bags (Multisets)
- A new theory of bags, which are collections that allow duplicates. It supports basic operators like union disjoint, union max, intersection, difference subtract, difference remove, duplicate removal, and multiplicity of an element in a bag.
-
Theory of Sequences
- A new parametric theory of sequences whose syntax is compatible with the syntax for sequences used by Z3.
- A new array-inspired procedure (option
--seq-array
).
-
Arithmetic
- Nonlinear real arithmetic is now solved using a new solver based on
cylindrical algebraic coverings. Includes full support for non-rational
models and a number of options
--nl-cov-*
for, e.g., different projection operators, Lazard's lifting or variable elimination. The new solver requires the libpoly library, and Lazard's lifting additionally requires CoCoALib.
- Nonlinear real arithmetic is now solved using a new solver based on
cylindrical algebraic coverings. Includes full support for non-rational
models and a number of options
-
Arrays
- Added support for an
eqrange
predicate.(eqrange a b i j)
is true if arraysa
andb
are equal on all indices within indicesi
andj
.
- Added support for an
-
Bit-vectors
- New bit-vector solver with CaDiCaL as default SAT back-end.
- New approach for solving bit-vectors as integers (option
--solve-bv-as-int
).
-
Datatypes
- Support for generic datatype updaters
((_ update s) t u)
which replaces the field specified by selectors
oft
by the valueu
.
- Support for generic datatype updaters
-
Integers
- Support for an integer operator
(_ iand n)
that returns the bitwiseand
of two integers, seen as integers modulo n. - Support for an integer operator
int.pow2
, used as(int.pow2 x)
which represents 2 to the power of x.
- Support for an integer operator
-
Quantifiers
- Improved support for enumerative instantiation (option
--enum-inst
). - SyGuS-based quantifier instantiation (option
--sygus-inst
).
- Improved support for enumerative instantiation (option
-
Strings
- Improved performance using new techniques, including model-based reductions, eager context-dependent simplification, and equality-based conflict finding.
- Support for
str.indexof_re(s, r, n)
, which returns the index of the first occurrence of a regular expressionr
in a strings
after indexn
or -1 ifr
does not match a substring aftern
.
-
Proofs
- Documentation available at: https://cvc5.github.io/docs/latest/proofs/proofs.html
- When used after an unsatisfiable response to
checkSat
,getProof
returns a representation of the refutation proof for the current set of assertions (get-proof in SMT-LIB). - Preliminary support for translations to external proof formats LFSC and Alethe.
-
Difficulty Estimation
- The API method
getDifficulty
returns a map from asserted formulas to integers which estimates how much that formula contributed to the difficulty of the overall problem (get-difficulty in SMT-LIB).
- The API method
-
Learned Literals
- The API method
getLearnedLiterals
gets a list of literals that are entailed by the current set of assertions that were learned during solving (get-learned-literals in SMT-LIB).
- The API method
-
Abduction and Interpolation
- The API method
getAbduct
can be used to find an abduct for the current set of assertions and provided goal (get-abduct in SMT-LIB). Optionally, a SyGuS grammar can be provided to restrict the shape of possible abducts. If using the text inferace, the grammar may be provided using the same syntax for grammars as in SyGuS IF format. - The API method
getInterpolant
can be used to find an interpolant for the current set of assertions and provided goal (get-interpolant in SMT-LIB). Like abduction, grammars may be provided to restrict the shape of interpolants.
- The API method
-
Support for Incremental Synthesis Queries
- The core SyGuS solver now supports getting multiple solutions for a
synthesis conjecture via the API. The method
checkSynthNext
finds the next SyGuS solution to the current set of SyGuS constraints (check-synth-next in SyGuS IF). getAbductNext
finds the next abduct for the current set of assertions and provided goal (get-abduct-next in SMT-LIB).getInterpolantNext
finds the next interpolant for the current set of assertions and provided goal (get-interpolant-next in SMT-LIB).
- The core SyGuS solver now supports getting multiple solutions for a
synthesis conjecture via the API. The method
-
Pool-based Quantifier Instantiation
- The API method
declarePool
declares symbol sets of terms called pools (declare-pool
in SMT-LIB). - Pools can be used in annotations of quantified formulas for fine grained control over quantifier instantiations (:inst-pool, :inst-add-to-pool, :skolem-add-to-pool in SMT-LIB).
- The API method
-
Diagnostic Outputs
- The option
-o TAG
can be used to enable a class of useful diagnostic information, such as the state of the input formula before and after pre-preprocessing, quantifier instantiations, literals learned during solving, among others. For SyGuS problems, it can be used to show candidate solutions and grammars that the solver has generated.
- The option
-
Unsat cores
- Production modes based on the new proof infrastructure
(
--unsat-cores-mode=sat-proof
) and on the solving-under-assumption feature of Minisat (--unsat-cores-mode=assumptions
). The mode based on SAT assumptions + preprocessing proofs is the new default. - Computing minimal unsat cores (option
--minimal-unsat-cores
).
- Production modes based on the new proof infrastructure
(
-
Blocking Models
- The API method
blockModels
can be used to block the current model using various policies for how to exclude the values of terms (block-model
in SMT-LIB). - The API method
blockModelValues
can be used to block the current model for a provided set of terms (block-model-values
in SMT-LIB).
- The API method
-
Model Cores
- The API method
isModelCoreSymbol
can be used to query whether the value for a symbol was critical to whether the model satisfies the current set of assertions. - Models can be limited to show only model core symbols (option
--model-cores
).
- The API method
Changes
- CaDiCaL and SymFPU are now required dependencies. CaDiCaL 1.4.1 is now the version used by default.
- Options have been extensively refactored, please refer to the cvc5 documentation for further information.
- Removed support for the CVC language.
- SyGuS: Removed support for SyGuS-IF 1.0.
- Removed support for the (non-standard)
define
command. - Removed the legacy API along with the Java and Python bindings for it.
- Interactive shell: the GPL-licensed Readline library has been replaced the
BSD-licensed Editline. Compiling with
--best
now enables Editline, instead of Readline. Without selecting optional GPL components, Editline-enabled CVC4 builds will be BSD licensed. - The
competition
build type includes the dependencies used for SMT-COMP by default. Note that this makes this build type produce GPL-licensed binaries. - Bit-vector operator
bvxnor
was previously mistakenly marked as left-assoicative in SMT-LIB. This has recently been corrected in SMT-LIB. We now restrictbvxnor
to only allow two operands in order to avoid confusion about the semantics, since the behavior of n-ary operands tobvxnor
is now undefined in SMT-LIB. - SMT-LIB output for
get-model
command now conforms with the standard, and does not begin with the keywordmodel
. The output is the same as before, only with this word removed from the beginning. - Building with Python 2 is now deprecated.
- The SMT-LIB syntax for some extensions has been changed. Notably, set
operators are now prefixed by
set.
, and relations byrel.
. For example,union
is now writtenset.union
. - Removed support for redundant logics
ALL_SUPPORTED
andQF_ALL_SUPPORTED
, useALL
andQF_ALL
instead.