Copyright | (c) Levent Erkok |
---|---|
License | BSD3 |
Maintainer | erkokl@gmail.com |
Stability | experimental |
Safe Haskell | None |
Language | Haskell2010 |
Data.SBV.Control
Description
Control sublanguage for interacting with SMT solvers.
Synopsis
- class MonadIO m => ExtractIO (m :: Type -> Type) where
- class Monad m => MonadQuery (m :: Type -> Type) where
- queryState :: m State
- type Query = QueryT IO
- query :: Query a -> Symbolic a
- data CheckSatResult
- checkSat :: Query CheckSatResult
- ensureSat :: Query ()
- checkSatUsing :: String -> Query CheckSatResult
- checkSatAssuming :: [SBool] -> Query CheckSatResult
- checkSatAssumingWithUnsatisfiableSet :: [SBool] -> Query (CheckSatResult, Maybe [SBool])
- getFunction :: (SymVal a, SymVal r, SMTFunction fun a r) => fun -> Query (Either (String, (Bool, Maybe [String], SExpr)) ([(a, r)], r))
- getUninterpretedValue :: HasKind a => SBV a -> Query String
- getModel :: Query SMTModel
- getAssignment :: Query [(String, Bool)]
- getSMTResult :: Query SMTResult
- getUnknownReason :: Query SMTReasonUnknown
- getObservables :: Query [(Name, CV)]
- getUnsatCore :: Query [String]
- getValue :: SymVal a => SBV a -> Query a
- getProof :: Query String
- getInterpolantMathSAT :: [String] -> Query String
- getInterpolantZ3 :: [SBool] -> Query String
- getAbduct :: Maybe String -> String -> SBool -> Query String
- getAbductNext :: Query String
- getAssertions :: Query [String]
- data SMTInfoFlag
- data SMTErrorBehavior
- data SMTInfoResponse
- getInfo :: SMTInfoFlag -> Query SMTInfoResponse
- getOption :: (a -> SMTOption) -> Query (Maybe SMTOption)
- getAssertionStackDepth :: Query Int
- push :: Int -> Query ()
- pop :: Int -> Query ()
- inNewAssertionStack :: Query a -> Query a
- caseSplit :: Bool -> [(String, SBool)] -> Query (Maybe (String, SMTResult))
- resetAssertions :: Query ()
- (|->) :: SymVal a => SBV a -> a -> Assignment
- mkSMTResult :: [Assignment] -> Query SMTResult
- exit :: Query ()
- ignoreExitCode :: SMTConfig -> Bool
- timeout :: Int -> Query a -> Query a
- queryDebug :: [String] -> Query ()
- echo :: String -> Query ()
- io :: IO a -> Query a
- data SMTOption
- = DiagnosticOutputChannel FilePath
- | ProduceAssertions Bool
- | ProduceAssignments Bool
- | ProduceProofs Bool
- | ProduceInterpolants Bool
- | ProduceUnsatAssumptions Bool
- | ProduceUnsatCores Bool
- | ProduceAbducts Bool
- | RandomSeed Integer
- | ReproducibleResourceLimit Integer
- | SMTVerbosity Integer
- | OptionKeyword String [String]
- | SetLogic Logic
- | SetInfo String [String]
- | SetTimeOut Integer
Documentation
In certain cases, the user might want to take over the communication with the solver, programmatically querying the engine and issuing commands accordingly. Queries can be extremely powerful as they allow direct control of the solver. Here's a simple example:
module Test where import Data.SBV import Data.SBV.Control -- queries require this module to be imported! test :: Symbolic (Maybe (Integer, Integer)) test = do x <- sInteger "x" -- a free variable named "x" y <- sInteger "y" -- a free variable named "y" -- require the sum to be 10 constrain $ x + y .== 10 -- Go into the Query mode query $ do -- Query the solver: Are the constraints satisfiable? cs <- checkSat case cs of Unk -> error "Solver said unknown!" DSat{} -> error "Solver said DSat!" Unsat -> return Nothing -- no solution! Sat -> -- Query the values: do xv <- getValue x yv <- getValue y io $ putStrLn $ "Solver returned: " ++ show (xv, yv) -- We can now add new constraints, -- Or perform arbitrary computations and tell -- the solver anything we want! constrain $ x .> literal xv + literal yv -- call checkSat again csNew <- checkSat case csNew of Unk -> error "Solver said unknown!" DSat{} -> error "Solver said DSat!" Unsat -> return Nothing Sat -> do xv2 <- getValue x yv2 <- getValue y return $ Just (xv2, yv2)
Note the type of test
: it returns an optional pair of integers in the Symbolic
monad. We turn
it into an IO value with the runSMT
function: (There's also runSMTWith
that uses a user specified
solver instead of the default. Note that z3
is best supported (and tested), if you use another solver your results may vary!)
pair :: IO (Maybe (Integer, Integer)) pair = runSMT test
When run, this can return:
*Test> pair Solver returned: (10,0) Just (11,-1)
demonstrating that the user has full contact with the solver and can guide it as the program executes. SBV provides access to many SMTLib features in the query mode, as exported from this very module.
For other examples see:
- Documentation.SBV.Examples.Queries.AllSat: Simulating SBV's
allSat
using queries. - Documentation.SBV.Examples.Queries.CaseSplit: Performing a case-split during a query.
- Documentation.SBV.Examples.Queries.Enums: Using enumerations in queries.
- Documentation.SBV.Examples.Queries.FourFours: Solution to a fun arithmetic puzzle, coded using queries.
- Documentation.SBV.Examples.Queries.GuessNumber: The famous number guessing game.
- Documentation.SBV.Examples.Queries.UnsatCore: Extracting unsat-cores using queries.
- Documentation.SBV.Examples.Queries.Interpolants: Extracting interpolants using queries.
User queries
class MonadIO m => ExtractIO (m :: Type -> Type) where Source #
Monads which support IO
operations and can extract all IO
behavior for
interoperation with functions like catches
, which takes
an IO
action in negative position. This function can not be implemented
for transformers like ReaderT r
or StateT s
, whose resultant IO
actions are a function of some environment or state.
Instances
ExtractIO IO Source # | Trivial IO extraction for |
ExtractIO m => ExtractIO (MaybeT m) Source # | IO extraction for |
ExtractIO m => ExtractIO (ExceptT e m) Source # | IO extraction for |
(Monoid w, ExtractIO m) => ExtractIO (WriterT w m) Source # | IO extraction for lazy |
(Monoid w, ExtractIO m) => ExtractIO (WriterT w m) Source # | IO extraction for strict |
class Monad m => MonadQuery (m :: Type -> Type) where Source #
Computations which support query operations.
Minimal complete definition
Nothing
Methods
queryState :: m State Source #
default queryState :: forall (t :: (Type -> Type) -> Type -> Type) (m' :: Type -> Type). (MonadTrans t, MonadQuery m', m ~ t m') => m State Source #
Instances
type Query = QueryT IO Source #
A query is a user-guided mechanism to directly communicate and extract results from the solver.
Checking satisfiability
data CheckSatResult Source #
Result of a checkSat
or checkSatAssuming
call.
Constructors
Sat | Satisfiable: A model is available, which can be queried with |
DSat (Maybe String) | Delta-satisfiable: A delta-sat model is available. String is the precision info, if available. |
Unsat | Unsatisfiable: No model is available. Unsat cores might be obtained via |
Unk | Unknown: Use |
Instances
checkSat :: Query CheckSatResult Source #
Check for satisfiability.
NB. For a version which generalizes over the underlying monad, see checkSat
ensureSat :: Query () Source #
Ensure that the current context is satisfiable. If not, this function will throw an error.
NB. For a version which generalizes over the underlying monad, see ensureSat
checkSatUsing :: String -> Query CheckSatResult Source #
Check for satisfiability with a custom check-sat-using command.
NB. For a version which generalizes over the underlying monad, see checkSatUsing
checkSatAssuming :: [SBool] -> Query CheckSatResult Source #
Check for satisfiability, under the given conditions. Similar to checkSat
except it allows making
further assumptions as captured by the first argument of booleans. (Also see checkSatAssumingWithUnsatisfiableSet
for a variant that returns the subset of the given assumptions that led to the Unsat
conclusion.)
NB. For a version which generalizes over the underlying monad, see checkSatAssuming
checkSatAssumingWithUnsatisfiableSet :: [SBool] -> Query (CheckSatResult, Maybe [SBool]) Source #
Check for satisfiability, under the given conditions. Returns the unsatisfiable
set of assumptions. Similar to checkSat
except it allows making further assumptions
as captured by the first argument of booleans. If the result is Unsat
, the user will
also receive a subset of the given assumptions that led to the Unsat
conclusion. Note
that while this set will be a subset of the inputs, it is not necessarily guaranteed to be minimal.
You must have arranged for the production of unsat assumptions first via
setOption
$ProduceUnsatAssumptions
True
for this call to not error out!
Usage note: getUnsatCore
is usually easier to use than checkSatAssumingWithUnsatisfiableSet
, as it
allows the use of named assertions, as obtained by namedConstraint
. If getUnsatCore
fills your needs, you should definitely prefer it over checkSatAssumingWithUnsatisfiableSet
.
NB. For a version which generalizes over the underlying monad, see checkSatAssumingWithUnsatisfiableSet
Querying the solver
Extracting values
getFunction :: (SymVal a, SymVal r, SMTFunction fun a r) => fun -> Query (Either (String, (Bool, Maybe [String], SExpr)) ([(a, r)], r)) Source #
Get the value of an uninterpreted function, as a list of domain, value pairs. The final value is the "else" clause, i.e., what the function maps values outside of the domain of the first list. If the result is not a value-association, then we get a string representation and the triple of whether it's curried, the argument list given by the user, and the s-expression as parsed by SBV from the SMT solver.
getUninterpretedValue :: HasKind a => SBV a -> Query String Source #
Get the value of an uninterpreted sort, as a String
NB. For a version which generalizes over the underlying monad, see getUninterpretedValue
getModel :: Query SMTModel Source #
Collect model values. It is implicitly assumed that we are in a check-sat
context. See getSMTResult
for a variant that issues a check-sat first and
returns an SMTResult
.
NB. For a version which generalizes over the underlying monad, see getModel
getAssignment :: Query [(String, Bool)] Source #
Retrieve the assignment. This is a lightweight version of getValue
, where the
solver returns the truth value for all named subterms of type Bool
.
You must have first arranged for assignments to be produced via
setOption
$ProduceAssignments
True
for this call to not error out!
NB. For a version which generalizes over the underlying monad, see getAssignment
getSMTResult :: Query SMTResult Source #
Issue check-sat and get an SMT Result out.
NB. For a version which generalizes over the underlying monad, see getSMTResult
getUnknownReason :: Query SMTReasonUnknown Source #
Get the reason unknown. Only internally used.
NB. For a version which generalizes over the underlying monad, see getUnknownReason
getObservables :: Query [(Name, CV)] Source #
Get the observables recorded during a query run.
NB. For a version which generalizes over the underlying monad, see getObservables
Extracting the unsat core
getUnsatCore :: Query [String] Source #
Retrieve the unsat-core. Note you must have arranged for unsat cores to be produced first via
setOption
$ProduceUnsatCores
True
for this call to not error out! Furthermore, unsat-cores require for the user to name the
constraints to be considered as part of the set, which is done via namedConstraint
.
NB. There is no notion of a minimal unsat-core, in case unsatisfiability can be derived in multiple ways. Furthermore, Z3 does not guarantee that the generated unsat core does not have any redundant assertions either, as doing so can incur a performance penalty. (There might be assertions in the set that is not needed.) To ensure all the assertions in the core are relevant, use:
setOption
$OptionKeyword
":smt.core.minimize" ["true"]
Note that this only works with Z3.
NB. For a version which generalizes over the underlying monad, see getUnsatCore
Getting the model value for a symbolic variable
getValue :: SymVal a => SBV a -> Query a Source #
Get the value of a term.
NB. For a version which generalizes over the underlying monad, see getValue
Extracting a proof
getProof :: Query String Source #
Retrieve the proof. Note you must have arranged for proofs to be produced first via
setOption
$ProduceProofs
True
for this call to not error out!
A proof is simply a String
, as returned by the solver. In the future, SBV might
provide a better datatype, depending on the use cases. Please get in touch if you
use this function and can suggest a better API.
NB. For a version which generalizes over the underlying monad, see getProof
Extracting interpolants
getInterpolantMathSAT :: [String] -> Query String Source #
Interpolant extraction for MathSAT. Compare with getInterpolantZ3
, which performs
similar function (but with a different use model) in Z3.
Retrieve an interpolant after an Unsat
result is obtained. Note you must have arranged for
interpolants to be produced first via
setOption
$ProduceInterpolants
True
for this call to not error out!
To get an interpolant for a pair of formulas A
and B
, use a constrainWithAttribute
call to attach
interplation groups to A
and B
. Then call getInterpolantMathSAT
["A"]
, assuming those are the names
you gave to the formulas in the A
group.
An interpolant for A
and B
is a formula I
such that:
A .=> I and B .=> sNot I
That is, it's evidence that A
and B
cannot be true together
since A
implies I
but B
implies not I
; establishing that A
and B
cannot
be satisfied at the same time. Furthermore, I
will have only the symbols that are common
to A
and B
.
NB. Interpolant extraction isn't standardized well in SMTLib. Currently both MathSAT and Z3 support them, but with slightly differing APIs. So, we support two APIs with slightly differing types to accommodate both. See Documentation.SBV.Examples.Queries.Interpolants for example usages in these solvers.
NB. For a version which generalizes over the underlying monad, see getInterpolantMathSAT
getInterpolantZ3 :: [SBool] -> Query String Source #
Interpolant extraction for z3. Compare with getInterpolantMathSAT
, which performs
similar function (but with a different use model) in MathSAT.
Unlike the MathSAT variant, you should simply call getInterpolantZ3
on symbolic booleans
to retrieve the interpolant. Do not call checkSat
or create named constraints. This makes it
harder to identify formulas, but the current state of affairs in interpolant API requires this kludge.
An interpolant for A
and B
is a formula I
such that:
A ==> I and B ==> not I
That is, it's evidence that A
and B
cannot be true together
since A
implies I
but B
implies not I
; establishing that A
and B
cannot
be satisfied at the same time. Furthermore, I
will have only the symbols that are common
to A
and B
.
In Z3, interpolants generalize to sequences: If you pass more than two formulas, then you will get
a sequence of interpolants. In general, for N
formulas that are not satisfiable together, you will be
returned N-1
interpolants. If formulas are A1 .. An
, then interpolants will be I1 .. I(N-1)
, such
that A1 ==> I1
, A2 /\ I1 ==> I2
, A3 /\ I2 ==> I3
, ..., and finally AN ===> not I(N-1)
.
Currently, SBV only returns simple and sequence interpolants, and does not support tree-interpolants. If you need these, please get in touch. Furthermore, the result will be a list of mere strings representing the interpolating formulas, as opposed to a more structured type. Please get in touch if you use this function and can suggest a better API.
NB. Interpolant extraction isn't standardized well in SMTLib. Currently both MathSAT and Z3 support them, but with slightly differing APIs. So, we support two APIs with slightly differing types to accommodate both. See Documentation.SBV.Examples.Queries.Interpolants for example usages in these solvers.
NB. For a version which generalizes over the underlying monad, see getInterpolantZ3
Getting abducts
getAbduct :: Maybe String -> String -> SBool -> Query String Source #
Get an abduct. The first argument is a conjecture. The return value will be an assertion such that in addition with the existing assertions you have, will imply this conjecture. The second argument is the grammar which guides the synthesis of this abduct, if given. Note that SBV doesn't do any checking on the grammar. See the relevant documentation on CVC5 for details.
NB. Before you use this function, make sure to call
setOption $ ProduceAbducts True
to enable abduct generation.
getAbductNext :: Query String Source #
Get the next abduct. Only call this after the first call to getAbduct
goes through. You can call
it repeatedly to get a different abduct.
Extracting assertions
getAssertions :: Query [String] Source #
Retrieve assertions. Note you must have arranged for assertions to be available first via
setOption
$ProduceAssertions
True
for this call to not error out!
Note that the set of assertions returned is merely a list of strings, just like the
case for getProof
. In the future, SBV might provide a better datatype, depending
on the use cases. Please get in touch if you use this function and can suggest
a better API.
NB. For a version which generalizes over the underlying monad, see getAssertions
Getting solver information
data SMTInfoFlag Source #
Collectable information from the solver.
Constructors
AllStatistics | |
AssertionStackLevels | |
Authors | |
ErrorBehavior | |
Name | |
ReasonUnknown | |
Version | |
InfoKeyword String |
Instances
Show SMTInfoFlag Source # | |
Defined in Data.SBV.Control.Types Methods showsPrec :: Int -> SMTInfoFlag -> ShowS # show :: SMTInfoFlag -> String # showList :: [SMTInfoFlag] -> ShowS # |
data SMTErrorBehavior Source #
Behavior of the solver for errors.
Constructors
ErrorImmediateExit | |
ErrorContinuedExecution |
Instances
Show SMTErrorBehavior Source # | |
Defined in Data.SBV.Control.Types Methods showsPrec :: Int -> SMTErrorBehavior -> ShowS # show :: SMTErrorBehavior -> String # showList :: [SMTErrorBehavior] -> ShowS # |
data SMTInfoResponse Source #
Collectable information from the solver.
Constructors
Resp_Unsupported | |
Resp_AllStatistics [(String, String)] | |
Resp_AssertionStackLevels Integer | |
Resp_Authors [String] | |
Resp_Error SMTErrorBehavior | |
Resp_Name String | |
Resp_ReasonUnknown SMTReasonUnknown | |
Resp_Version String | |
Resp_InfoKeyword String [String] |
Instances
Show SMTInfoResponse Source # | |
Defined in Data.SBV.Control.Types Methods showsPrec :: Int -> SMTInfoResponse -> ShowS # show :: SMTInfoResponse -> String # showList :: [SMTInfoResponse] -> ShowS # |
getInfo :: SMTInfoFlag -> Query SMTInfoResponse Source #
Ask solver for info.
NB. For a version which generalizes over the underlying monad, see getInfo
getOption :: (a -> SMTOption) -> Query (Maybe SMTOption) Source #
Retrieve the value of an 'SMTOption.' The curious function argument is on purpose here,
simply pass the constructor name. Example: the call
will return
either getOption
ProduceUnsatCores
Nothing
or Just (ProduceUnsatCores True)
or Just (ProduceUnsatCores False)
.
Result will be Nothing
if the solver does not support this option.
NB. For a version which generalizes over the underlying monad, see getOption
Entering and exiting assertion stack
getAssertionStackDepth :: Query Int Source #
The current assertion stack depth, i.e., #push - #pops after start. Always non-negative.
NB. For a version which generalizes over the underlying monad, see getAssertionStackDepth
push :: Int -> Query () Source #
Push the context, entering a new one. Pushes multiple levels if n > 1.
NB. For a version which generalizes over the underlying monad, see push
pop :: Int -> Query () Source #
Pop the context, exiting a new one. Pops multiple levels if n > 1. It's an error to pop levels that don't exist.
NB. For a version which generalizes over the underlying monad, see pop
inNewAssertionStack :: Query a -> Query a Source #
Run the query in a new assertion stack. That is, we push the context, run the query commands, and pop it back.
NB. For a version which generalizes over the underlying monad, see inNewAssertionStack
Higher level tactics
caseSplit :: Bool -> [(String, SBool)] -> Query (Maybe (String, SMTResult)) Source #
Search for a result via a sequence of case-splits, guided by the user. If one of
the conditions lead to a satisfiable result, returns Just
that result. If none of them
do, returns Nothing
. Note that we automatically generate a coverage case and search
for it automatically as well. In that latter case, the string returned will be Coverage.
The first argument controls printing progress messages See Documentation.SBV.Examples.Queries.CaseSplit
for an example use case.
NB. For a version which generalizes over the underlying monad, see caseSplit
Resetting the solver state
resetAssertions :: Query () Source #
Reset the solver, by forgetting all the assertions. However, bindings are kept as is,
as opposed to a full reset of the solver. Use this variant to clean-up the solver
state while leaving the bindings intact. Pops all assertion levels. Declarations and
definitions resulting from the setLogic
command are unaffected. Note that SBV
implicitly uses global-declarations, so bindings will remain intact.
NB. For a version which generalizes over the underlying monad, see resetAssertions
Constructing assignments
(|->) :: SymVal a => SBV a -> a -> Assignment infix 1 Source #
Make an assignment. The type Assignment
is abstract, the result is typically passed
to mkSMTResult
:
mkSMTResult [ a |-> 332 , b |-> 2.3 , c |-> True ]
End users should use getModel
for automatically constructing models from the current solver state.
However, an explicit Assignment
might be handy in complex scenarios where a model needs to be
created manually.
Terminating the query
mkSMTResult :: [Assignment] -> Query SMTResult Source #
Produce the query result from an assignment.
NB. For a version which generalizes over the underlying monad, see mkSMTResult
Exit the solver. This action will cause the solver to terminate. Needless to say, trying to communicate with the solver after issuing "exit" will simply fail.
NB. For a version which generalizes over the underlying monad, see exit
Controlling the solver behavior
ignoreExitCode :: SMTConfig -> Bool Source #
If true, we shall ignore the exit code upon exit. Otherwise we require ExitSuccess.
timeout :: Int -> Query a -> Query a Source #
Timeout a query action, typically a command call to the underlying SMT solver.
The duration is in microseconds (1/10^6
seconds). If the duration
is negative, then no timeout is imposed. When specifying long timeouts, be careful not to exceed
maxBound :: Int
. (On a 64 bit machine, this bound is practically infinite. But on a 32 bit
machine, it corresponds to about 36 minutes!)
Semantics: The call timeout n q
causes the timeout value to be applied to all interactive calls that take place
as we execute the query q
. That is, each call that happens during the execution of q
gets a separate
time-out value, as opposed to one timeout value that limits the whole query. This is typically the intended behavior.
It is advisable to apply this combinator to calls that involve a single call to the solver for
finer control, as opposed to an entire set of interactions. However, different use cases might call for different scenarios.
If the solver responds within the time-out specified, then we continue as usual. However, if the backend solver times-out using this mechanism, there is no telling what the state of the solver will be. Thus, we raise an error in this case.
NB. For a version which generalizes over the underlying monad, see timeout
Miscellaneous
queryDebug :: [String] -> Query () Source #
If verbose
is True
, print the message, useful for debugging messages
in custom queries. Note that redirectVerbose
will be respected: If a
file redirection is given, the output will go to the file.
NB. For a version which generalizes over the underlying monad, see queryDebug
echo :: String -> Query () Source #
Echo a string. Note that the echoing is done by the solver, not by SBV.
NB. For a version which generalizes over the underlying monad, see echo
io :: IO a -> Query a Source #
Perform an arbitrary IO action.
NB. For a version which generalizes over the underlying monad, see io
Solver options
Option values that can be set in the solver, following the SMTLib specification https://smt-lib.org/language.shtml.
Note that not all solvers may support all of these!
Furthermore, SBV doesn't support the following options allowed by SMTLib.
:interactive-mode
(Deprecated in SMTLib, useProduceAssertions
instead.):print-success
(SBV critically needs this to be True in query mode.):produce-models
(SBV always sets this option so it can extract models.):regular-output-channel
(SBV always requires regular output to come on stdout for query purposes.):global-declarations
(SBV always uses global declarations since definitions are accumulative.)
Note that SetLogic
and SetInfo
are, strictly speaking, not SMTLib options. However, we treat it as such here
uniformly, as it fits better with how options work.
Constructors
DiagnosticOutputChannel FilePath | |
ProduceAssertions Bool | |
ProduceAssignments Bool | |
ProduceProofs Bool | |
ProduceInterpolants Bool | |
ProduceUnsatAssumptions Bool | |
ProduceUnsatCores Bool | |
ProduceAbducts Bool | |
RandomSeed Integer | |
ReproducibleResourceLimit Integer | |
SMTVerbosity Integer | |
OptionKeyword String [String] | |
SetLogic Logic | |
SetInfo String [String] | |
SetTimeOut Integer |