Example #1
0
box naive_icp::solve(box b, contractor const & ctc, SMTConfig & config) {
    vector<box> solns;
    vector<box> box_stack;
    box_stack.push_back(b);
    do {
        DREAL_LOG_INFO << "icp_loop()"
                       << "\t" << "box stack Size = " << box_stack.size();
        b = box_stack.back();
        box_stack.pop_back();
        try {
            b = ctc.prune(b, config);
            if (config.nra_use_stat) { config.nra_stat.increase_prune(); }
        } catch (contractor_exception & e) {
            // Do nothing
        }
        if (!b.is_empty()) {
            tuple<int, box, box> splits = b.bisect(config.nra_precision);
            if (config.nra_use_stat) { config.nra_stat.increase_branch(); }
            int const i = get<0>(splits);
            if (i >= 0) {
                box const & first  = get<1>(splits);
                box const & second = get<2>(splits);
                if (second.is_bisectable()) {
                    box_stack.push_back(second);
                    box_stack.push_back(first);
                } else {
                    box_stack.push_back(first);
                    box_stack.push_back(second);
                }
                if (config.nra_proof) {
                    config.nra_proof_out << "[branched on "
                                         << b.get_name(i)
                                         << "]" << endl;
                }
            } else {
                config.nra_found_soln++;
                if (config.nra_found_soln >= config.nra_multiple_soln) {
                    break;
                }
                if (config.nra_multiple_soln > 1) {
                    // If --multiple_soln is used
                    output_solution(b, config, config.nra_found_soln);
                }
                solns.push_back(b);
            }
        }
    } while (box_stack.size() > 0);
    if (config.nra_multiple_soln > 1 && solns.size() > 0) {
        return solns.back();
    } else {
        assert(!b.is_empty() || box_stack.size() == 0);
        // cerr << "BEFORE ADJUST_BOUND\n==================\n" << b << "=========================\n\n\n";
        b.adjust_bound(box_stack);
        // cerr << "AFTER  ADJUST_BOUND\n==================\n" << b << "=========================\n\n\n";
        return b;
    }
}
Example #2
0
box ncbt_icp::solve(box b, contractor const & ctc, SMTConfig & config) {
    static unsigned prune_count = 0;
    vector<box> box_stack;
    vector<int> bisect_var_stack;
    box_stack.push_back(b);
    bisect_var_stack.push_back(-1);  // Dummy var
    do {
        // Loop Invariant
        assert(box_stack.size() == bisect_var_stack.size());
        DREAL_LOG_INFO << "new_icp_loop()"
                       << "\t" << "box stack Size = " << box_stack.size();
        b = box_stack.back();
        try {
            b = ctc.prune(b, config);
            if (config.nra_use_stat) { config.nra_stat.increase_prune(); }
        } catch (contractor_exception & e) {
            // Do nothing
        }
        prune_count++;
        box_stack.pop_back();
        bisect_var_stack.pop_back();
        if (!b.is_empty()) {
            // SAT
            tuple<int, box, box> splits = b.bisect(config.nra_precision);
            if (config.nra_use_stat) { config.nra_stat.increase_branch(); }
            int const index = get<0>(splits);
            if (index >= 0) {
                box const & first    = get<1>(splits);
                box const & second   = get<2>(splits);
                if (second.is_bisectable()) {
                    box_stack.push_back(second);
                    box_stack.push_back(first);
                } else {
                    box_stack.push_back(first);
                    box_stack.push_back(second);
                }
                bisect_var_stack.push_back(index);
                bisect_var_stack.push_back(index);
            } else {
                break;
            }
        } else {
            // UNSAT
            while (box_stack.size() > 0) {
                assert(box_stack.size() == bisect_var_stack.size());
                int bisect_var = bisect_var_stack.back();
                ibex::BitSet const & input = ctc.input();
                DREAL_LOG_DEBUG << ctc;
                if (!input[bisect_var]) {
                    box_stack.pop_back();
                    bisect_var_stack.pop_back();
                } else {
                    break;
                }
            }
        }
    } while (box_stack.size() > 0);
    DREAL_LOG_DEBUG << "prune count = " << prune_count;
    b.adjust_bound(box_stack);
    return b;
}