Package org.sosy_lab.java_smt.api

Interface InterpolatingProverEnvironment<T>

Type Parameters:
T - The type of the objects which can be used to select formulas for interpolant creation.
All Superinterfaces:
AutoCloseable, BasicProverEnvironment<T>
All Known Implementing Classes:
InterpolatingProverWithAssumptionsWrapper
public interface InterpolatingProverEnvironment<T> extends BasicProverEnvironment<T>
This class provides an interface to an incremental SMT solver with methods for pushing and popping formulas as well as SAT checks. Furthermore, interpolants can be generated for an unsatisfiable list of formulas.
See Also:

  • Method Details

    • getInterpolant

      BooleanFormula getInterpolant(Collection<T> formulasOfA) throws SolverException, InterruptedException
      Get an interpolant for two groups of formulas. This should be called only immediately after an BasicProverEnvironment.isUnsat() call that returned true.

      There is no direct guarantee that the interpolants returned are part of an inductive sequence', however this seems to work for most (all?) solvers as long as the same proof is used, i.e. all interpolants are computed after the same SAT-check.

      Parameters:
      formulasOfA - A collection of values returned by BasicProverEnvironment.push(BooleanFormula). All the corresponding formulas from group A, the remaining formulas form group B.
      Returns:
      An interpolant for A and B
      Throws:
      SolverException - if interpolant cannot be computed, for example because interpolation procedure is incomplete
      InterruptedException

    • getSeqInterpolants

      default List<BooleanFormula> getSeqInterpolants(List<? extends Collection<T>> partitionedFormulas) throws SolverException, InterruptedException
      This method returns interpolants of an 'inductive sequence'. This property must be supported by the interpolation-strategy of the underlying SMT-solver! Depending on the underlying SMT-solver this method might be faster than N direct calls to getInterpolant().

      The prover stack should contain the partitioned formulas, but any order is allowed. For an input of N partitions we return N-1 interpolants. Any asserted formula that is on the prover stack and not part of the partitioned list, will be used for background theory and its symbols can appear in any interpolant.

      Returns:
      a 'inductive sequence' of interpolants, such that the implication AND(I_i, P_i) => I_(i+1) is satisfied for all i, where P_i is the conjunction of all formulas in partition i.
      Throws:
      SolverException - if interpolant cannot be computed, for example because interpolation procedure is incomplete
      InterruptedException

    • getSeqInterpolants0

      default List<BooleanFormula> getSeqInterpolants0(List<T> formulas) throws SolverException, InterruptedException
      This utility method wraps each formula in a collection and then forwards to getSeqInterpolants(java.util.List<? extends java.util.Collection<T>>).
      Throws:
      SolverException
      InterruptedException
      See Also:

    • getTreeInterpolants

      List<BooleanFormula> getTreeInterpolants(List<? extends Collection<T>> partitionedFormulas, int[] startOfSubTree) throws SolverException, InterruptedException
      Compute a sequence of interpolants. The nesting array describes the start of the subtree for tree interpolants. For inductive sequences of interpolants use a nesting array completely filled with 0.

      Example: 

       A  D
 |  |
 B  E
 | /
 C
 |
 F  H
 | /
 G

 arrayIndex     = [0,1,2,3,4,5,6,7]  // only for demonstration, not needed
 partition      = [A,B,D,E,C,F,H,G]  // post-order of tree
 startOfSubTree = [0,0,2,2,0,0,6,0]  // index of left-most leaf of the current element

      The prover stack should contain the partitioned formulas. For an input of N partitions (nodes in the tree) we return N-1 interpolants (one interpolant for/below each node except the root). Any asserted formula that is on the prover stack and not part of the partitioned list, will be used for background theory and its symbols can appear in any interpolant.

      Parameters:
      partitionedFormulas - of formulas
      startOfSubTree - The start of the subtree containing the formula at this index as root.
      Returns:
      Tree interpolants respecting the nesting relation.
      Throws:
      SolverException - if interpolant cannot be computed, for example because interpolation procedure is incomplete
      InterruptedException

    • getTreeInterpolants0

      default List<BooleanFormula> getTreeInterpolants0(List<T> formulas, int[] startOfSubTree) throws SolverException, InterruptedException
      This utility method wraps each formula in a collection and then forwards to getTreeInterpolants(java.util.List<? extends java.util.Collection<T>>, int[]).
      Throws:
      SolverException
      InterruptedException
      See Also:

    • checkTreeStructure

      static boolean checkTreeStructure(int numOfPartitions, int[] startOfSubTree)
      Checks for a valid subtree-structure. This code is taken from SMTinterpol.