Examples with Expr com.microsoft.z3.Expr used on opensource projects

Example 21 with Expr

use of com.microsoft.z3.Expr in project batfish by batfish.

the class SymbolicRoute method addExprs.

// TODO: depends on configuration
/*
   * Check if a particular protocol on a router is configured
   * to use multipath routing or not.
   */
/* private boolean isMultipath(String router, Protocol proto, boolean isIbgp) {
    Configuration conf = _enc.getGraph().getConfigurations().get(router);
    if (proto.isConnected()) {
      return true;
    } else if (proto.isStatic()) {
      return true;
    } else if (proto.isOspf()) {
      return true;
    } else if (proto.isBgp()) {
      BgpProcess p = conf.getDefaultVrf().getBgpProcess();
      if (isIbgp) {
        return p.getMultipathIbgp();
      } else {
        return p.getMultipathEbgp();
      }
    } else {
      return true;
    }
  } */
private void addExprs(EncoderSlice enc) {
    Map<String, Expr> all = enc.getAllVariables();
    all.put(_permitted.toString(), _permitted);
    if (_adminDist != null) {
        all.put(_adminDist.toString(), _adminDist);
    }
    if (_med != null) {
        all.put(_med.toString(), _med);
    }
    if (_localPref != null) {
        all.put(_localPref.toString(), _localPref);
    }
    if (_metric != null) {
        all.put(_metric.toString(), _metric);
    }
    if (_prefixLength != null) {
        all.put(_prefixLength.toString(), _prefixLength);
    }
    if (_routerId != null) {
        all.put(_routerId.toString(), _routerId);
    }
    if (_bgpInternal != null) {
        all.put(_bgpInternal.toString(), _bgpInternal);
    }
    if (_ospfArea != null) {
        all.put(_ospfArea.getBitVec().toString(), _ospfArea.getBitVec());
    }
    if (_ospfType != null) {
        all.put(_ospfType.getBitVec().toString(), _ospfType.getBitVec());
    }
    if (_clientId != null) {
        all.put(_clientId.getBitVec().toString(), _clientId.getBitVec());
    }
    if (_igpMetric != null) {
        all.put(_igpMetric.toString(), _igpMetric);
    }
    for (BoolExpr var : _communities.values()) {
        all.put(var.toString(), var);
    }
}

Example 22 with Expr

use of com.microsoft.z3.Expr in project batfish by batfish.

the class TransferSSA method compute.

/*
   * Convert a list of statements into a Z3 boolean expression for the transfer function.
   */
private TransferResult<BoolExpr, BoolExpr> compute(List<Statement> statements, TransferParam<SymbolicRoute> p, TransferResult<BoolExpr, BoolExpr> result) {
    boolean doesReturn = false;
    for (Statement stmt : statements) {
        if (stmt instanceof StaticStatement) {
            StaticStatement ss = (StaticStatement) stmt;
            switch(ss.getType()) {
                case ExitAccept:
                    doesReturn = true;
                    p.debug("ExitAccept");
                    result = returnValue(p, result, true);
                    break;
                case ReturnTrue:
                    doesReturn = true;
                    p.debug("ReturnTrue");
                    result = returnValue(p, result, true);
                    break;
                case ExitReject:
                    doesReturn = true;
                    p.debug("ExitReject");
                    result = returnValue(p, result, false);
                    break;
                case ReturnFalse:
                    doesReturn = true;
                    p.debug("ReturnFalse");
                    result = returnValue(p, result, false);
                    break;
                case SetDefaultActionAccept:
                    p.debug("SetDefaulActionAccept");
                    p = p.setDefaultAccept(true);
                    break;
                case SetDefaultActionReject:
                    p.debug("SetDefaultActionReject");
                    p = p.setDefaultAccept(false);
                    break;
                case SetLocalDefaultActionAccept:
                    p.debug("SetLocalDefaultActionAccept");
                    p = p.setDefaultAcceptLocal(true);
                    break;
                case SetLocalDefaultActionReject:
                    p.debug("SetLocalDefaultActionReject");
                    p = p.setDefaultAcceptLocal(false);
                    break;
                case ReturnLocalDefaultAction:
                    p.debug("ReturnLocalDefaultAction");
                    // TODO: need to set local default action in an environment
                    if (p.getDefaultAcceptLocal()) {
                        result = returnValue(p, result, true);
                    } else {
                        result = returnValue(p, result, false);
                    }
                    break;
                case FallThrough:
                    p.debug("Fallthrough");
                    result = fallthrough(p, result);
                    break;
                case Return:
                    // TODO: assumming this happens at the end of the function, so it is ignored for now.
                    p.debug("Return");
                    break;
                case RemovePrivateAs:
                    p.debug("RemovePrivateAs");
                    System.out.println("Warning: use of unimplemented feature RemovePrivateAs");
                    break;
                default:
                    throw new BatfishException("TODO: computeTransferFunction: " + ss.getType());
            }
        } else if (stmt instanceof If) {
            p.debug("If");
            If i = (If) stmt;
            TransferResult<BoolExpr, BoolExpr> r = compute(i.getGuard(), p);
            result = result.addChangedVariables(r);
            BoolExpr guard = (BoolExpr) r.getReturnValue().simplify();
            String str = guard.toString();
            // If there are updates in the guard, add them to the parameter p before entering branches
            for (Pair<String, Expr> changed : r.getChangedVariables()) {
                p.debug("CHANGED: " + changed.getFirst());
                updateSingleValue(p, changed.getFirst(), changed.getSecond());
            }
            p.debug("guard: " + str);
            // If we know the branch ahead of time, then specialize
            switch(str) {
                case "true":
                    p.debug("True Branch");
                    result = compute(i.getTrueStatements(), p.indent(), result);
                    break;
                case "false":
                    p.debug("False Branch");
                    compute(i.getFalseStatements(), p.indent(), result);
                    break;
                default:
                    p.debug("True Branch");
                    // clear changed variables before proceeding
                    TransferParam<SymbolicRoute> p1 = p.indent().setData(p.getData().copy());
                    TransferParam<SymbolicRoute> p2 = p.indent().setData(p.getData().copy());
                    TransferResult<BoolExpr, BoolExpr> trueBranch = compute(i.getTrueStatements(), p1, initialResult());
                    p.debug("False Branch");
                    TransferResult<BoolExpr, BoolExpr> falseBranch = compute(i.getFalseStatements(), p2, initialResult());
                    p.debug("JOIN");
                    PList<Pair<String, Pair<Expr, Expr>>> pairs = trueBranch.mergeChangedVariables(falseBranch);
                    // Extract and deal with the return value first so that other
                    // variables have this reflected in their value
                    int idx = pairs.find(pair -> pair.getFirst().equals("RETURN"));
                    if (idx >= 0) {
                        Pair<String, Pair<Expr, Expr>> ret = pairs.get(idx);
                        pairs = pairs.minus(idx);
                        pairs = pairs.plus(pairs.size(), ret);
                    }
                    for (Pair<String, Pair<Expr, Expr>> pair : pairs) {
                        String s = pair.getFirst();
                        p.debug("CHANGED: " + s);
                        Pair<Expr, Expr> x = joinPoint(p, result, guard, pair);
                        result = result.addChangedVariable(s, x.getFirst());
                        if (s.equals("RETURN")) {
                            result = result.setReturnValue((BoolExpr) x.getFirst()).setReturnAssignedValue((BoolExpr) x.getSecond());
                        }
                        if (s.equals("FALLTHROUGH")) {
                            result = result.setFallthroughValue((BoolExpr) x.getFirst()).setReturnAssignedValue((BoolExpr) x.getSecond());
                        }
                    }
                    break;
            }
        } else if (stmt instanceof SetDefaultPolicy) {
            p.debug("SetDefaultPolicy");
            p = p.setDefaultPolicy((SetDefaultPolicy) stmt);
        } else if (stmt instanceof SetMetric) {
            p.debug("SetMetric");
            // TODO: what is the semantics for BGP? Is this MED?
            if (!_current.getProto().isBgp()) {
                SetMetric sm = (SetMetric) stmt;
                LongExpr ie = sm.getMetric();
                ArithExpr newValue = applyLongExprModification(p.getData().getMetric(), ie);
                newValue = _enc.mkIf(result.getReturnAssignedValue(), p.getData().getMetric(), newValue);
                ArithExpr x = createArithVariableWith(p, "METRIC", newValue);
                p.getData().setMetric(x);
                result = result.addChangedVariable("METRIC", x);
            }
        } else if (stmt instanceof SetOspfMetricType) {
            p.debug("SetOspfMetricType");
            SetOspfMetricType somt = (SetOspfMetricType) stmt;
            OspfMetricType mt = somt.getMetricType();
            SymbolicOspfType t;
            if (mt == OspfMetricType.E1) {
                t = new SymbolicOspfType(_enc, OspfType.E1);
            } else {
                t = new SymbolicOspfType(_enc, OspfType.E2);
            }
            BitVecExpr newValue = t.getBitVec();
            newValue = _enc.mkIf(result.getReturnAssignedValue(), p.getData().getOspfType().getBitVec(), newValue);
            BitVecExpr x = createBitVecVariableWith(p, "OSPF-TYPE", 2, newValue);
            p.getData().getOspfType().setBitVec(x);
            result = result.addChangedVariable("OSPF-TYPE", x);
        } else if (stmt instanceof SetLocalPreference) {
            p.debug("SetLocalPreference");
            SetLocalPreference slp = (SetLocalPreference) stmt;
            IntExpr ie = slp.getLocalPreference();
            ArithExpr newValue = applyIntExprModification(p.getData().getLocalPref(), ie);
            newValue = _enc.mkIf(result.getReturnAssignedValue(), p.getData().getLocalPref(), newValue);
            ArithExpr x = createArithVariableWith(p, "LOCAL-PREF", newValue);
            p.getData().setLocalPref(x);
            result = result.addChangedVariable("LOCAL-PREF", x);
        } else if (stmt instanceof AddCommunity) {
            p.debug("AddCommunity");
            AddCommunity ac = (AddCommunity) stmt;
            Set<CommunityVar> comms = _enc.getGraph().findAllCommunities(_conf, ac.getExpr());
            for (CommunityVar cvar : comms) {
                BoolExpr newValue = _enc.mkIf(result.getReturnAssignedValue(), p.getData().getCommunities().get(cvar), _enc.mkTrue());
                BoolExpr x = createBoolVariableWith(p, cvar.getValue(), newValue);
                p.getData().getCommunities().put(cvar, x);
                result = result.addChangedVariable(cvar.getValue(), x);
            }
        } else if (stmt instanceof SetCommunity) {
            p.debug("SetCommunity");
            SetCommunity sc = (SetCommunity) stmt;
            Set<CommunityVar> comms = _enc.getGraph().findAllCommunities(_conf, sc.getExpr());
            for (CommunityVar cvar : comms) {
                BoolExpr newValue = _enc.mkIf(result.getReturnAssignedValue(), p.getData().getCommunities().get(cvar), _enc.mkTrue());
                BoolExpr x = createBoolVariableWith(p, cvar.getValue(), newValue);
                p.getData().getCommunities().put(cvar, x);
                result = result.addChangedVariable(cvar.getValue(), x);
            }
        } else if (stmt instanceof DeleteCommunity) {
            p.debug("DeleteCommunity");
            DeleteCommunity ac = (DeleteCommunity) stmt;
            Set<CommunityVar> comms = _enc.getGraph().findAllCommunities(_conf, ac.getExpr());
            Set<CommunityVar> toDelete = new HashSet<>();
            // Find comms to delete
            for (CommunityVar cvar : comms) {
                if (cvar.getType() == Type.REGEX) {
                    toDelete.addAll(_enc.getCommunityDependencies().get(cvar));
                } else {
                    toDelete.add(cvar);
                }
            }
            // Delete each community
            for (CommunityVar cvar : toDelete) {
                BoolExpr newValue = _enc.mkIf(result.getReturnAssignedValue(), p.getData().getCommunities().get(cvar), _enc.mkFalse());
                BoolExpr x = createBoolVariableWith(p, cvar.getValue(), newValue);
                p.getData().getCommunities().put(cvar, x);
                result = result.addChangedVariable(cvar.getValue(), x);
            }
        } else if (stmt instanceof RetainCommunity) {
            p.debug("RetainCommunity");
        // no op
        } else if (stmt instanceof PrependAsPath) {
            p.debug("PrependAsPath");
            PrependAsPath pap = (PrependAsPath) stmt;
            Integer prependCost = prependLength(pap.getExpr());
            ArithExpr newValue = _enc.mkSum(p.getData().getMetric(), _enc.mkInt(prependCost));
            newValue = _enc.mkIf(result.getReturnAssignedValue(), p.getData().getMetric(), newValue);
            ArithExpr x = createArithVariableWith(p, "METRIC", newValue);
            p.getData().setMetric(x);
            result = result.addChangedVariable("METRIC", x);
        } else if (stmt instanceof SetOrigin) {
            p.debug("SetOrigin");
            System.out.println("Warning: use of unimplemented feature SetOrigin");
        } else if (stmt instanceof SetNextHop) {
            p.debug("SetNextHop");
            System.out.println("Warning: use of unimplemented feature SetNextHop");
        } else {
            String s = (_isExport ? "export" : "import");
            String msg = String.format("Unimplemented feature %s for %s transfer function on interface %s", stmt.toString(), s, _graphEdge.toString());
            throw new BatfishException(msg);
        }
    }
    // If this is the outermost call, then we relate the variables
    if (p.getInitialCall()) {
        p.debug("InitialCall finalizing");
        // Apply the default action
        if (!doesReturn) {
            p.debug("Applying default action: " + p.getDefaultAccept());
            if (p.getDefaultAccept()) {
                result = returnValue(p, result, true);
            } else {
                result = returnValue(p, result, false);
            }
        }
        BoolExpr related = relateVariables(p, result);
        BoolExpr retValue = _enc.mkIf(result.getReturnValue(), related, _enc.mkNot(_current.getPermitted()));
        result = result.setReturnValue(retValue);
    }
    return result;
}

Example 23 with Expr

use of com.microsoft.z3.Expr in project batfish by batfish.

the class TransferSSA method compute.

/*
   * Convert a Batfish AST boolean expression to a symbolic Z3 boolean expression
   * by performing inlining of stateful side effects.
   */
private TransferResult<BoolExpr, BoolExpr> compute(BooleanExpr expr, TransferParam<SymbolicRoute> p) {
    // TODO: right now everything is IPV4
    if (expr instanceof MatchIpv4) {
        p.debug("MatchIpv4");
        return fromExpr(_enc.mkTrue());
    }
    if (expr instanceof MatchIpv6) {
        p.debug("MatchIpv6");
        return fromExpr(_enc.mkFalse());
    }
    if (expr instanceof Conjunction) {
        p.debug("Conjunction");
        Conjunction c = (Conjunction) expr;
        BoolExpr acc = _enc.mkTrue();
        TransferResult<BoolExpr, BoolExpr> result = new TransferResult<>();
        for (BooleanExpr be : c.getConjuncts()) {
            TransferResult<BoolExpr, BoolExpr> r = compute(be, p.indent());
            result = result.addChangedVariables(r);
            acc = _enc.mkAnd(acc, r.getReturnValue());
        }
        p.debug("has changed variable");
        return result.setReturnValue(acc);
    }
    if (expr instanceof Disjunction) {
        p.debug("Disjunction");
        Disjunction d = (Disjunction) expr;
        BoolExpr acc = _enc.mkFalse();
        TransferResult<BoolExpr, BoolExpr> result = new TransferResult<>();
        for (BooleanExpr be : d.getDisjuncts()) {
            TransferResult<BoolExpr, BoolExpr> r = compute(be, p.indent());
            result = result.addChangedVariables(r);
            acc = _enc.mkOr(acc, r.getReturnValue());
        }
        p.debug("has changed variable");
        return result.setReturnValue(acc);
    }
    if (expr instanceof ConjunctionChain) {
        p.debug("ConjunctionChain");
        ConjunctionChain d = (ConjunctionChain) expr;
        List<BooleanExpr> conjuncts = new ArrayList<>(d.getSubroutines());
        if (p.getDefaultPolicy() != null) {
            BooleanExpr be = new CallExpr(p.getDefaultPolicy().getDefaultPolicy());
            conjuncts.add(be);
        }
        if (conjuncts.size() == 0) {
            return fromExpr(_enc.mkTrue());
        } else {
            TransferResult<BoolExpr, BoolExpr> result = new TransferResult<>();
            BoolExpr acc = _enc.mkFalse();
            for (int i = conjuncts.size() - 1; i >= 0; i--) {
                BooleanExpr conjunct = conjuncts.get(i);
                TransferParam<SymbolicRoute> param = p.setDefaultPolicy(null).setChainContext(TransferParam.ChainContext.CONJUNCTION);
                TransferResult<BoolExpr, BoolExpr> r = compute(conjunct, param);
                result = result.addChangedVariables(r);
                acc = _enc.mkIf(r.getFallthroughValue(), acc, r.getReturnValue());
            }
            p.debug("ConjunctionChain Result: " + acc);
            return result.setReturnValue(acc);
        }
    }
    if (expr instanceof DisjunctionChain) {
        p.debug("DisjunctionChain");
        DisjunctionChain d = (DisjunctionChain) expr;
        List<BooleanExpr> disjuncts = new ArrayList<>(d.getSubroutines());
        if (p.getDefaultPolicy() != null) {
            BooleanExpr be = new CallExpr(p.getDefaultPolicy().getDefaultPolicy());
            disjuncts.add(be);
        }
        if (disjuncts.size() == 0) {
            return fromExpr(_enc.mkTrue());
        } else {
            TransferResult<BoolExpr, BoolExpr> result = new TransferResult<>();
            BoolExpr acc = _enc.mkFalse();
            for (int i = disjuncts.size() - 1; i >= 0; i--) {
                BooleanExpr disjunct = disjuncts.get(i);
                TransferParam<SymbolicRoute> param = p.setDefaultPolicy(null).setChainContext(TransferParam.ChainContext.CONJUNCTION);
                TransferResult<BoolExpr, BoolExpr> r = compute(disjunct, param);
                result.addChangedVariables(r);
                acc = _enc.mkIf(r.getFallthroughValue(), acc, r.getReturnValue());
            }
            p.debug("DisjunctionChain Result: " + acc);
            return result.setReturnValue(acc);
        }
    }
    if (expr instanceof Not) {
        p.debug("mkNot");
        Not n = (Not) expr;
        TransferResult<BoolExpr, BoolExpr> result = compute(n.getExpr(), p);
        return result.setReturnValue(_enc.mkNot(result.getReturnValue()));
    }
    if (expr instanceof MatchProtocol) {
        MatchProtocol mp = (MatchProtocol) expr;
        Protocol proto = Protocol.fromRoutingProtocol(mp.getProtocol());
        if (proto == null) {
            p.debug("MatchProtocol(" + mp.getProtocol().protocolName() + "): false");
            return fromExpr(_enc.mkFalse());
        }
        if (_other.getProtocolHistory() == null) {
            BoolExpr protoMatch = _enc.mkBool(proto.equals(_proto));
            p.debug("MatchProtocol(" + mp.getProtocol().protocolName() + "): " + protoMatch);
            return fromExpr(protoMatch);
        }
        BoolExpr protoMatch = _other.getProtocolHistory().checkIfValue(proto);
        p.debug("MatchProtocol(" + mp.getProtocol().protocolName() + "): " + protoMatch);
        return fromExpr(protoMatch);
    }
    if (expr instanceof MatchPrefixSet) {
        p.debug("MatchPrefixSet");
        MatchPrefixSet m = (MatchPrefixSet) expr;
        // For BGP, may change prefix length
        TransferResult<BoolExpr, BoolExpr> result = matchPrefixSet(_conf, m.getPrefixSet(), p.getData());
        return result.setReturnAssignedValue(_enc.mkTrue());
    // TODO: implement me
    } else if (expr instanceof MatchPrefix6Set) {
        p.debug("MatchPrefix6Set");
        return fromExpr(_enc.mkFalse());
    } else if (expr instanceof CallExpr) {
        p.debug("CallExpr");
        // TODO: the call can modify certain fields, need to keep track of these variables
        CallExpr c = (CallExpr) expr;
        String name = c.getCalledPolicyName();
        RoutingPolicy pol = _conf.getRoutingPolicies().get(name);
        p = p.setCallContext(TransferParam.CallContext.EXPR_CALL);
        TransferResult<BoolExpr, BoolExpr> r = compute(pol.getStatements(), p.indent().enterScope(name), initialResult());
        p.debug("CallExpr (return): " + r.getReturnValue());
        p.debug("CallExpr (fallthrough): " + r.getFallthroughValue());
        return r;
    } else if (expr instanceof WithEnvironmentExpr) {
        p.debug("WithEnvironmentExpr");
        // TODO: this is not correct
        WithEnvironmentExpr we = (WithEnvironmentExpr) expr;
        // TODO: postStatements() and preStatements()
        return compute(we.getExpr(), p);
    } else if (expr instanceof MatchCommunitySet) {
        p.debug("MatchCommunitySet");
        MatchCommunitySet mcs = (MatchCommunitySet) expr;
        return fromExpr(matchCommunitySet(_conf, mcs.getExpr(), p.getData()));
    } else if (expr instanceof BooleanExprs.StaticBooleanExpr) {
        BooleanExprs.StaticBooleanExpr b = (BooleanExprs.StaticBooleanExpr) expr;
        switch(b.getType()) {
            case CallExprContext:
                p.debug("CallExprContext");
                return fromExpr(_enc.mkBool(p.getCallContext() == TransferParam.CallContext.EXPR_CALL));
            case CallStatementContext:
                p.debug("CallStmtContext");
                return fromExpr(_enc.mkBool(p.getCallContext() == TransferParam.CallContext.STMT_CALL));
            case True:
                p.debug("True");
                return fromExpr(_enc.mkTrue());
            case False:
                p.debug("False");
                return fromExpr(_enc.mkFalse());
            default:
                throw new BatfishException("Unhandled " + BooleanExprs.class.getCanonicalName() + ": " + b.getType());
        }
    } else if (expr instanceof MatchAsPath) {
        p.debug("MatchAsPath");
        System.out.println("Warning: use of unimplemented feature MatchAsPath");
        return fromExpr(_enc.mkFalse());
    }
    String s = (_isExport ? "export" : "import");
    String msg = String.format("Unimplemented feature %s for %s transfer function on interface %s", expr.toString(), s, _graphEdge.toString());
    throw new BatfishException(msg);
}

Example 24 with Expr

use of com.microsoft.z3.Expr in project batfish by batfish.

the class TransferResult method mergeChangedVariables.

// TODO: this really needs to use persistent set data types
public PList<Pair<String, Pair<Expr, Expr>>> mergeChangedVariables(TransferResult<U, T> other) {
    Set<String> seen = new HashSet<>();
    PList<Pair<String, Pair<Expr, Expr>>> vars = PList.empty();
    for (Pair<String, Expr> cv1 : this._changedVariables) {
        String s = cv1.getFirst();
        Expr x = cv1.getSecond();
        if (!seen.contains(s)) {
            seen.add(s);
            Expr e = find(other._changedVariables, s);
            Pair<Expr, Expr> pair = new Pair<>(x, e);
            vars = vars.plus(new Pair<>(s, pair));
        }
    }
    for (Pair<String, Expr> cv1 : other._changedVariables) {
        String s = cv1.getFirst();
        Expr x = cv1.getSecond();
        if (!seen.contains(s)) {
            seen.add(s);
            Expr e = find(this._changedVariables, s);
            // preserve order
            Pair<Expr, Expr> pair = new Pair<>(e, x);
            vars = vars.plus(new Pair<>(s, pair));
        }
    }
    return vars;
}

Example 25 with Expr

use of com.microsoft.z3.Expr in project batfish by batfish.

the class VerificationResult method debug.

public void debug(EncoderSlice enc, boolean showConstraints, String filter) {
    if (showConstraints) {
        System.out.println("================= Constraints ==================");
        for (BoolExpr be : enc.getSolver().getAssertions()) {
            String x = be.simplify().toString();
            if (filter == null || x.contains(filter)) {
                System.out.println(x);
            }
        }
    }
    if (_verified) {
        System.out.println("verified");
    } else {
        System.out.println("================= Model ================");
        enc.getSymbolicDecisions().getDataForwarding().forEach((router, map) -> map.forEach((edge, e) -> {
            String expr = e.toString();
            if (expr.contains("DATA-")) {
                String result = _model.get(expr);
                if ("true".equals(result)) {
                    System.out.println(edge);
                }
            }
        }));
        System.out.println("");
        _model.forEach((var, val) -> {
            if (filter == null || var.contains(filter)) {
                System.out.println(var + "=" + val);
            }
        });
    }
    if (enc.getUnsatCore().getDoTrack()) {
        System.out.println("================= Unsat Core ================");
        for (BoolExpr be : enc.getSolver().getUnsatCore()) {
            BoolExpr constraint = enc.getUnsatCore().getTrackingVars().get(be.toString());
            System.out.println("Var: " + be);
            System.out.println(constraint);
            System.out.println("");
        }
    }
}