Package org.sosy_lab.java_smt.api

Interface FormulaManager

    • Method Detail

      • getIntegerFormulaManager

        IntegerFormulaManager getIntegerFormulaManager()
        Returns the Integer-Theory. Because most SAT-solvers support automatic casting between Integer- and Rational-Theory, the Integer- and the RationalFormulaManager both return the same Formulas for numeric operations like ADD, SUBTRACT, TIMES, LESSTHAN, EQUAL and others.
        Throws:
        UnsupportedOperationException - If the theory is not supported by the solver.

      • getRationalFormulaManager

        RationalFormulaManager getRationalFormulaManager()
        Returns the Rational-Theory. Because most SAT-solvers support automatic casting between Integer- and Rational-Theory, the Integer- and the RationalFormulaManager both return the same Formulas for numeric operations like ADD, SUBTRACT, TIMES, LESSTHAN, EQUAL, etc.
        Throws:
        UnsupportedOperationException - If the theory is not supported by the solver.

      • getUFManager

        UFManager getUFManager()
        Returns the function for dealing with uninterpreted functions (UFs).

      • makeVariable

        <T extends Formula> T makeVariable​(FormulaType<T> formulaType,
                                   String name)
        Create variable of the type equal to formulaType.
        Parameters:
        formulaType - the type of the variable.
        name - the name of the variable.
        Returns:
        the created variable.

      • makeApplication

        <T extends Formula> T makeApplication​(FunctionDeclaration<T> declaration,
                                      List<? extends Formula> args)
        Create a function application to the given list of arguments.
        Parameters:
        declaration - Function declaration
        args - List of arguments
        Returns:
        Constructed formula

      • makeApplication

        <T extends Formula> T makeApplication​(FunctionDeclaration<T> declaration,
                                      Formula... args)
        Create a function application to the given list of arguments.
        Parameters:
        declaration - Function declaration
        args - List of arguments
        Returns:
        Constructed formula

      • getFormulaType

        <T extends Formula> FormulaType<T> getFormulaType​(T formula)
        Returns the type of the given Formula.

      • parse

        BooleanFormula parse​(String s)
              throws IllegalArgumentException
        Parse a boolean formula given as a String in an SMTLIB file format. We expect exactly one assertion to be contained in the query.

        Example: (declare-fun x () Int)(assert (= 0 x))

        It depends on the used SMT solver whether the given query must be self-contained and include declarations for all used symbols or not, and also whether the query is allowed to contain symbols with equal name, but different type/sort than existing symbols. The safest way is to always declare all used symbols and to avoid conflicting types for them.

        The behavior of the SMT solver is undefined if commands are provided in the SMTLIB-based String that are different from declarations or an assertion, such as push/pop or set-info. Most solvers just ignore those commands.

        Variables that are defined, but not used in the assertion, might be ignored by the SMT solver and they might not be available for later usage.

        Returns:
        A single formula from the assertion in the internal representation.
        Throws:
        IllegalArgumentException - If the string cannot be parsed.

      • dumpFormula

        Appender dumpFormula​(BooleanFormula pT)
        Serialize an input formula to an SMT-LIB format. Very useful when passing formulas between different solvers.

        To get a String, simply call Object.toString() on the returned object. This method is lazy and does not create an output string until the returned object is actually used.

        Returns:
        SMT-LIB formula serialization.

      • simplify

        <T extends Formula> T simplify​(T input)
                        throws InterruptedException
        Simplify an input formula, while ensuring equivalence.

        For solvers that do not provide a simplification API, an original formula is returned.

        Parameters:
        input - The input formula
        Returns:
        Simplified version of the formula
        Throws:
        InterruptedException

      • visit

        @CanIgnoreReturnValue
<R> R visit​(Formula f,
            FormulaVisitor<R> rFormulaVisitor)
        Visit the formula with a given visitor.

        This method does not recursively visit sub-components of a formula its own, so the given FormulaVisitor needs to call such visitation on its own.

        Please be aware that calling this method might cause extensive stack usage depending on the nesting of the given formula and the given FormulaVisitor. Additionally, sub-formulas that are used several times in the formula might be visited several times. For an efficient formula traversing, we also provide visitRecursively(Formula, FormulaVisitor).

        Parameters:
        f - formula to be visited
        rFormulaVisitor - an implementation that provides steps for each kind of formula.

      • visitRecursively

        void visitRecursively​(Formula f,
                      FormulaVisitor<TraversalProcess> rFormulaVisitor)
        Visit the formula recursively with a given FormulaVisitor. This method traverses sub-components of a formula automatically, depending on the return value of the TraversalProcess in the given FormulaVisitor.

        This method guarantees that the traversal is done iteratively, without using Java recursion, and thus is not prone to StackOverflowErrors.

        Furthermore, this method also guarantees that every equal part of the formula is visited only once. Thus, it can be used to traverse DAG-like formulas efficiently.

        The traversal is done in PRE-ORDER manner with regard to caching identical subtrees, i.e., a parent will be visited BEFORE its children. The unmodified child-formulas are passed as argument to the parent's visitation.

      • transformRecursively

        <T extends Formula> T transformRecursively​(T f,
                                           FormulaTransformationVisitor pFormulaVisitor)
        Visit the formula recursively with a given FormulaVisitor.

        This method guarantees that the traversal is done iteratively, without using Java recursion, and thus is not prone to StackOverflowErrors.

        Furthermore, this method also guarantees that every equal part of the formula is visited only once. Thus, it can be used to traverse DAG-like formulas efficiently.

        The traversal is done in POST-ORDER manner with regard to caching identical subtrees, i.e., a parent will be visited AFTER its children. The result of the child-visitation is passed as argument to the parent's visitation.

        Parameters:
        pFormulaVisitor - Transformation described by the user.

      • extractVariables

        ImmutableMap<String,​Formula> extractVariables​(Formula f)
        Extract the names of all free variables and UFs in a formula.
        Parameters:
        f - The input formula
        Returns:
        Map from variable names to the corresponding formulas.

      • extractVariablesAndUFs

        ImmutableMap<String,​Formula> extractVariablesAndUFs​(Formula f)
        Extract the names of all free variables and UFs in a formula.
        Parameters:
        f - The input formula
        Returns:
        Map from variable names to the corresponding formulas. If an UF occurs multiple times in the input formula, an arbitrary instance of an application of this UF is in the map.

      • substitute

        <T extends Formula> T substitute​(T f,
                                 Map<? extends Formula,​? extends Formula> fromToMapping)
        Substitute every occurrence of any item from changeFrom in formula f to the corresponding occurrence from changeTo.

        E.g. if changeFrom contains a variable a and changeTo contains a variable b all occurrences of a will be changed to b in the returned formula.

        Parameters:
        f - Formula to change.
        fromToMapping - Mapping of old and new formula parts.
        Returns:
        Formula with parts replaced.

      • translateFrom

        BooleanFormula translateFrom​(BooleanFormula formula,
                             FormulaManager otherManager)
        Translates the formula from another context into the context represented by this. Default implementation relies on string serialization (dumpFormula(BooleanFormula) and parse(String)), but each solver may implement more efficient translation between its own contexts.
        Parameters:
        formula - Formula belonging to otherContext.
        otherManager - Formula manager belonging to the other context.
        Returns:
        Formula belonging to this context.

      • isValidName

        boolean isValidName​(String variableName)
        Check whether the given String can be used as symbol/name for variables or undefined functions.

        We explicitly state that with further development of SMT solvers and the SMTLib specification, the list of forbidden variable names may change in the future. Users should if possible not use logical or mathematical operators, or keywords strongly depending on SMTlib.

        If a variable name is rejected, a possibility is escaping, e.g. either substituting the whole variable name or just every invalid character with an escaped form. We recommend using an escape sequence based on the token "JAVASMT", because it might be unusual enough to appear when encoding a user's problem in SMT. Please note that you might also have to handle escaping the escape sequence. Examples:

        • the invalid variable name "=" (logical operator for equality) can be replaced with a string "JAVASMT_EQUALS".
        • the invalid SMTlib-escaped variable name "|test|" (the solver SMTInterpol does not allow the pipe symbol "|" in names) can be replaced with "JAVASMT_PIPEtestJAVASMT_PIPE".

      • escape

        String escape​(String variableName)
        Get an escaped symbol/name for variables or undefined functions, if necessary.

        See isValidName(String) for further details.

      • unescape

        String unescape​(String variableName)
        Unescape the symbol/name for variables or undefined functions, if necessary.

        The result is undefined for Strings that are not properly escaped.

        See isValidName(String) for further details.