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Getting started

For existing code examples, please see our examples.

Step 1: Install JavaSMT

Automatic Installation using Ivy (preferred)

If your build tool supports fetching packages from Apache Ivy, you can point it to Sosy-Lab Ivy repository, which would automatically fetch JavaSMT and all of its dependencies.

After the repository URL is configured, you only need to add the following dependency:

<dependency org="org.sosy_lab" name="java-smt" rev="3.7.0"/>

Automatic Installation from Maven Central (possibly outdated)

If you use Maven/Gradle/SBT/etc to build your project, a dependency to JavaSMT can be added using a single configuration item.

For Maven:

<dependency>
  <groupId>org.sosy-lab</groupId>
  <artifactId>java-smt</artifactId>
  <version>3.7.0-61-gea80187e</version>
</dependency>

Currently, only SMTInterpol and Princess are automatically fetched from Maven Central, because they are written in Java and Scala, and thus are available on every machine. Shared object for the solvers MathSAT5 and Z3 can be added by using additional dependencies (example for Linux):

    <!-- MathSAT5 has one dependency -->
    <dependency>
      <groupId>org.sosy-lab</groupId>
      <artifactId>javasmt-solver-mathsat5</artifactId>
      <version>5.6.5</version>
      <type>so</type>
    </dependency>

    <!-- Z3 has three dependencies -->
    <dependency>
      <groupId>org.sosy-lab</groupId>
      <artifactId>javasmt-solver-z3</artifactId>
      <version>4.8.10</version>
    </dependency>
    <dependency>
      <groupId>org.sosy-lab</groupId>
      <artifactId>javasmt-solver-z3</artifactId>
      <version>4.8.10</version>
      <type>so</type>
      <classifier>libz3</classifier>
    </dependency>
    <dependency>
      <groupId>org.sosy-lab</groupId>
      <artifactId>javasmt-solver-z3</artifactId>
      <version>4.8.10</version>
      <type>so</type>
      <classifier>libz3java</classifier>
    </dependency>

The XML snippets for other solvers available via Maven, such as Boolector and CVC4, can be found in the POM file of our Example-Maven-Project.

If you are not using Linux and we provide a solver binary for your system, you might need to set the dependencies accordingly, e.g., change the type from so to dll (for Windows) or dylib (for MacOS). You can lookup the required dependency files and filename extension in the Ivy repository.

Additionally you can add and configure some Maven plugins to load the libraries automatically and place them in the correct directories when assembling your application. The plugins copy all dependencies (including the solver binaries) to the target/dependency directory and rename the libraries as required for automated loading. A detailed explanation for these plugins is given in the Example-Maven-Project/pom.xml. For testing, you might need to add the dependency directory to the classpath for your test-engine.

Example:

<configuration>
  <argLine>-Djava.library.path=${project.build.directory}/dependency</argLine>
</configuration>

And finally configure the classpath for your jar-plugin:

<manifest>
  <addClasspath>true</addClasspath>
  <classpathPrefix>${project.build.directory}/dependency</classpathPrefix>
</manifest>

See Example-Maven-Project for more information and a working example. See Example-Maven-Web-Project for more information about a Dynamic-Web-Project runnable by Tomcat 9.

Shared object for other solvers still need to be installed manually: see the section "Manual Installation" below.

Manual Installation

JARs for JavaSMT and its dependencies can be downloaded from our Ivy repository manually. In order to perform the manual installation, the following steps should be followed:

  • The desired version has to be chosen. Latest version can be found by looking at the Ivy index. JavaSMT might not yet support the latest version on the solver's webpage, but only the latest version in the Ivy index.
  • Suppose the version 3.7.0 was chosen. Ivy description file ivy-3.7.0.xml can be consulted in order to determine all the files which should be fetched.
  • The artifacts tag specifies what files the release depends on. In the example case, those are java-smt-3.7.0.jar and (optionally) java-smt-3.7.0-sources.jar, located in the same directory.
  • Finally, the dependencies can be manually followed and resolved. E.g. in the example, Z3 version 4.8.9-sosy0 is specified, which is described by the corresponding XML file, specifying what binaries should be fetched from the corresponding directory.

Binaries for Native Solvers

When using Ivy or Maven for installation on a 64-bit Linux platform, solver binaries for native solvers are downloaded automatically, if available. Some solvers are also available for supporting Windows or MacOS. Everything should work as is after installation.

Without Ivy or Maven you need to download and install the binaries manually as described above under Manual Installation. You can either copy them into the directory of the JavaSMT JAR file, or in a directory ../native/<arch>-<os>/ relative to the directory of the JAR file. See NativeLibraries documentation for more details on which path is searched.

For systems other than 64-bit Linux (e.g., Windows, MacOS, or 32-bit systems) we might not always provide binaries, so you need to download or compile them for yourself. You can find the necessary steps for compiling and using solver binaries in lib/native/source/ and build. Solvers which run directly on JDK (currently Princess and SMTInterpol) do not require any configuration and work out of the box.

Currently, the support for newly integrated solvers like Boolector, CVC4, and Yices2 is limited. We are working on supporting more solvers on more operating systems. A helping hand or feedback is also welcome.

Step 2: Initialization

Below is a small example showing how to initialize the library using the entry point SolverContextFactory:

public class TestApp {
  public static void main(String[] args) throws InvalidConfigurationException {
    Configuration config = Configuration.fromCmdLineArguments(args);
    LogManager logger = BasicLogManager.create(config);
    ShutdownManager shutdown = ShutdownManager.create();

    // SolverContext is a class wrapping a solver context.
    // Solver can be selected either using an argument or a configuration option
    // inside `config`.
    SolverContext context = SolverContextFactory.createSolverContext(
        config, logger, shutdown.getNotifier(), Solvers.SMTINTERPOL);
  }
}

JavaSMT relies on three dependencies from the SoSy-Lab Common library. These dependencies are:

  • Configuration: JavaSMT accepts some configuration options and forwards options to the underlying SMT solver.
  • LogManager: JavaSMT can be configured to provide extensive logging for the operations related to all SMT queries.
  • ShutdownNotifier from a ShutdownManager: Many SMT queries can take a very long time, potentially more than the user is willing to wait. What's more, for a solver implemented in the native code usual ways of interrupting a Java process (e.g. interrupt signal) would not work. Shutdown manager provides a solution to gracefully request termination, and JavaSMT and the solvers will try to respond to such requests as soon as possible.

Here is how to get an instance of these dependencies:

Dependency Dummy instance that does nothing Regular instance
Configuration Configuration.defaultConfiguration() Configuration.fromCmdLineArguments(String[]) or Configuration.builder()...build() for more flexible definition of options (e.g., from .properties files)
LogManager LogManager.createNullLogManager() BasicLogManager.create(Configuration) for logging to the JDK logging API; for other logging frameworks just write a wrapper implementing LogManager
ShutdownNotifier ShutdownNotifier.createDummy() ShutdownManager.create().getNotifier()

Step 3: Solving Constraints

Once the SolverContext is initialized, we can start posing queries to the solver. In this example, we want to find a satisfying example for a constraint over integers a, b and c:

a + b = c \/ a + c = 2 * b

Creating the required constraint is straightforward:

    // Assume we have a SolverContext instance.
    FormulaManager fmgr = context.getFormulaManager();

    BooleanFormulaManager bmgr = fmgr.getBooleanFormulaManager();
    IntegerFormulaManager imgr = fmgr.getIntegerFormulaManager();

    IntegerFormula a = imgr.makeVariable("a"),
                   b = imgr.makeVariable("b"),
                   c = imgr.makeVariable("c");
    BooleanFormula constraint = bmgr.or(
        imgr.equal(
            imgr.add(a, b), c
        ),
        imgr.equal(
            imgr.add(a, c), imgr.multiply(imgr.makeNumber(2), b)
        )
    );

Note the types of the formulas: IntegerFormula and BooleanFormula. Using different classes for different types of formulas adds additional guarantees at compile-time: unless and unsafe cast is used, it is impossible to e.g. add an integer to a boolean using JavaSMT API.

Once the constraint is generated, we can solve it and get the model:

    try (ProverEnvironment prover = context.newProverEnvironment(ProverOptions.GENERATE_MODELS)) {
      prover.addConstraint(constraint);
      boolean isUnsat = prover.isUnsat();
      if (!isUnsat) {
        Model model = prover.getModel();
      }
    }

Try-with-resources syntax will dispose of the prover once solving is finished.

Once the model is obtained we can get values from it either by iterating through all of the returned data, or by querying for the variables we need:

    BigInteger value = model.evaluate(a);

For further information, look at our full example HoudiniApp, other examples, or at the JavaDoc.