Skip to content
Snippets Groups Projects
Select Git revision
  • ha_mcp
  • master default protected
  • pac_composite_target_mce
  • ramsey_k_order
  • 4.6
  • occbin
  • uop
  • rework_pac
  • aux_vars_fix
  • created_preprocessor_repo
10 results

ModelTree.cc

Blame
  • Forked from Dynare / preprocessor
    643 commits behind the upstream repository.
    ModelTree.cc 72.21 KiB
    /*
     * Copyright © 2003-2022 Dynare Team
     *
     * This file is part of Dynare.
     *
     * Dynare is free software: you can redistribute it and/or modify
     * it under the terms of the GNU General Public License as published by
     * the Free Software Foundation, either version 3 of the License, or
     * (at your option) any later version.
     *
     * Dynare is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     * GNU General Public License for more details.
     *
     * You should have received a copy of the GNU General Public License
     * along with Dynare.  If not, see <https://www.gnu.org/licenses/>.
     */
    
    #include "ModelTree.hh"
    #include "VariableDependencyGraph.hh"
    #pragma GCC diagnostic push
    #pragma GCC diagnostic ignored "-Wold-style-cast"
    #pragma GCC diagnostic ignored "-Wsign-compare"
    #pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
    #include <boost/graph/adjacency_list.hpp>
    #include <boost/graph/max_cardinality_matching.hpp>
    #include <boost/graph/topological_sort.hpp>
    #pragma GCC diagnostic pop
    
    #ifdef __APPLE__
    # include <mach-o/dyld.h>
    #endif
    
    #include <regex>
    #include <utility>
    
    void
    ModelTree::copyHelper(const ModelTree &m)
    {
      auto f = [this](expr_t e) { return e->clone(*this); };
    
      // Equations
      for (const auto &it : m.equations)
        equations.push_back(dynamic_cast<BinaryOpNode *>(f(it)));
      for (const auto &it : m.aux_equations)
        aux_equations.push_back(dynamic_cast<BinaryOpNode *>(f(it)));
    
      auto convert_deriv_map = [f](map<vector<int>, expr_t> dm)
                               {
                                 map<vector<int>, expr_t> dm2;
                                 for (const auto &it : dm)
                                   dm2.emplace(it.first, f(it.second));
                                 return dm2;
                               };
    
      // Derivatives
      for (const auto &it : m.derivatives)
        derivatives.push_back(convert_deriv_map(it));
      for (const auto &it : m.params_derivatives)
        params_derivatives[it.first] = convert_deriv_map(it.second);
    
      auto convert_temporary_terms_t = [f](temporary_terms_t tt)
                                       {
                                         temporary_terms_t tt2;
                                         for (const auto &it : tt)
                                           tt2.insert(f(it));
                                         return tt2;
                                       };
    
      // Temporary terms
      for (const auto &it : m.temporary_terms_mlv)
        temporary_terms_mlv[dynamic_cast<VariableNode *>(f(it.first))] = f(it.second);
      for (const auto &it : m.temporary_terms_derivatives)
        temporary_terms_derivatives.push_back(convert_temporary_terms_t(it));
      for (const auto &it : m.temporary_terms_idxs)
        temporary_terms_idxs[f(it.first)] = it.second;
      for (const auto &it : m.params_derivs_temporary_terms)
        params_derivs_temporary_terms[it.first] = convert_temporary_terms_t(it.second);
      for (const auto &it : m.params_derivs_temporary_terms_idxs)
        params_derivs_temporary_terms_idxs[f(it.first)] = it.second;
    
      // Other stuff
      for (const auto &it : m.trend_symbols_map)
        trend_symbols_map[it.first] = f(it.second);
      for (const auto &it : m.nonstationary_symbols_map)
        nonstationary_symbols_map[it.first] = {it.second.first, f(it.second.second)};
    
      for (const auto &it : m.equation_type_and_normalized_equation)
        equation_type_and_normalized_equation.emplace_back(it.first, dynamic_cast<BinaryOpNode *>(f(it.second)));
    
      for (const auto &it : m.blocks_derivatives)
        {
          map<tuple<int, int, int>, expr_t> v;
          for (const auto &it2 : it)
            v[it2.first] = f(it2.second);
          blocks_derivatives.push_back(v);
        }
    
      auto convert_vector_tt = [f](vector<temporary_terms_t> vtt)
                               {
                                 vector<temporary_terms_t> vtt2;
                                 for (const auto &tt : vtt)
                                   {
                                     temporary_terms_t tt2;
                                     for (const auto &it : tt)
                                       tt2.insert(f(it));
                                     vtt2.push_back(tt2);
                                   }
                                 return vtt2;
                               };
      for (const auto &it : m.blocks_temporary_terms)
        blocks_temporary_terms.push_back(convert_vector_tt(it));
      for (const auto &it : m.blocks_temporary_terms_idxs)
        blocks_temporary_terms_idxs[f(it.first)] = it.second;
    }
    
    ModelTree::ModelTree(SymbolTable &symbol_table_arg,
                         NumericalConstants &num_constants_arg,
                         ExternalFunctionsTable &external_functions_table_arg,
                         bool is_dynamic_arg) :
      DataTree{symbol_table_arg, num_constants_arg, external_functions_table_arg, is_dynamic_arg},
      derivatives(4),
      NNZDerivatives(4, 0),
      temporary_terms_derivatives(4)
    {
    }
    
    ModelTree::ModelTree(const ModelTree &m) :
      DataTree{m},
      user_set_add_flags{m.user_set_add_flags},
      user_set_subst_flags{m.user_set_subst_flags},
      user_set_add_libs{m.user_set_add_libs},
      user_set_subst_libs{m.user_set_subst_libs},
      user_set_compiler{m.user_set_compiler},
      equations_lineno{m.equations_lineno},
      equation_tags{m.equation_tags},
      computed_derivs_order{m.computed_derivs_order},
      NNZDerivatives{m.NNZDerivatives},
      eq_idx_block2orig{m.eq_idx_block2orig},
      endo_idx_block2orig{m.endo_idx_block2orig},
      eq_idx_orig2block{m.eq_idx_orig2block},
      endo_idx_orig2block{m.endo_idx_orig2block},
      blocks{m.blocks},
      endo2block{m.endo2block},
      eq2block{m.eq2block},
      endo2eq{m.endo2eq},
      cutoff{m.cutoff},
      mfs{m.mfs}
    {
      copyHelper(m);
    }
    
    ModelTree &
    ModelTree::operator=(const ModelTree &m)
    {
      DataTree::operator=(m);
    
      equations.clear();
      equations_lineno = m.equations_lineno;
      aux_equations.clear();
      equation_tags = m.equation_tags;
      computed_derivs_order = m.computed_derivs_order;
      NNZDerivatives = m.NNZDerivatives;
    
      derivatives.clear();
      params_derivatives.clear();
    
      temporary_terms_mlv.clear();
      temporary_terms_derivatives.clear();
      params_derivs_temporary_terms.clear();
      params_derivs_temporary_terms_idxs.clear();
    
      trend_symbols_map.clear();
      nonstationary_symbols_map.clear();
    
      eq_idx_block2orig = m.eq_idx_block2orig;
      endo_idx_block2orig = m.endo_idx_block2orig;
      eq_idx_orig2block = m.eq_idx_orig2block;
      endo_idx_orig2block = m.endo_idx_orig2block;
      equation_type_and_normalized_equation.clear();
      blocks_derivatives.clear();
      blocks = m.blocks;
      endo2block = m.endo2block;
      eq2block = m.eq2block;
      blocks_temporary_terms.clear();
      blocks_temporary_terms_idxs.clear();
      endo2eq = m.endo2eq;
      cutoff = m.cutoff;
      mfs = m.mfs;
    
      user_set_add_flags = m.user_set_add_flags;
      user_set_subst_flags = m.user_set_subst_flags;
      user_set_add_libs = m.user_set_add_libs;
      user_set_subst_libs = m.user_set_subst_libs;
      user_set_compiler = m.user_set_compiler;
    
      copyHelper(m);
    
      return *this;
    }
    
    bool
    ModelTree::computeNormalization(const jacob_map_t &contemporaneous_jacobian, bool verbose)
    {
      const int n = equations.size();
    
      assert(n == symbol_table.endo_nbr());
    
      using BipartiteGraph = boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS>;
    
      /*
        Vertices 0 to n-1 are for endogenous (using type specific ID)
        Vertices n to 2*n-1 are for equations (using equation no.)
      */
      BipartiteGraph g(2 * n);
    
      // Fill in the graph
      for (const auto &[eq_and_endo, val] : contemporaneous_jacobian)
        add_edge(eq_and_endo.first + n, eq_and_endo.second, g);
    
      // Compute maximum cardinality matching
      vector<int> mate_map(2*n);
    
      bool check = checked_edmonds_maximum_cardinality_matching(g, &mate_map[0]);
    
      assert(check);
    
    #ifdef DEBUG
      for (int i = 0; i < n; i++)
        cout << "Endogenous " << symbol_table.getName(symbol_table.getID(eEndogenous, i))
             << " matched with equation " << (mate_map[i]-n+1) << endl;
    #endif
    
      // Create the resulting map, by copying the n first elements of mate_map, and substracting n to them
      endo2eq.resize(equations.size());
      transform(mate_map.begin(), mate_map.begin() + n, endo2eq.begin(), [=](int i) { return i-n; });
    
      // Check if all variables are normalized
      if (auto it = find(mate_map.begin(), mate_map.begin() + n, boost::graph_traits<BipartiteGraph>::null_vertex());
          it != mate_map.begin() + n)
        {
          if (verbose)
            cerr << "ERROR: Could not normalize the model. Variable "
                 << symbol_table.getName(symbol_table.getID(SymbolType::endogenous, it - mate_map.begin()))
                 << " is not in the maximum cardinality matching." << endl;
          check = false;
        }
      return check;
    }
    
    void
    ModelTree::computeNonSingularNormalization(const jacob_map_t &contemporaneous_jacobian)
    {
      cout << "Normalizing the model..." << endl;
    
      int n = equations.size();
    
      // Compute the maximum value of each row of the contemporaneous Jacobian matrix
      vector<double> max_val(n, 0.0);
      for (const auto &[eq_and_endo, val] : contemporaneous_jacobian)
        max_val[eq_and_endo.first] = max(max_val[eq_and_endo.first], fabs(val));
    
      // Compute normalized contemporaneous Jacobian
      jacob_map_t normalized_contemporaneous_jacobian(contemporaneous_jacobian);
      for (auto &[eq_and_endo, val] : normalized_contemporaneous_jacobian)
        val /= max_val[eq_and_endo.first];
    
      // We start with the highest value of the cutoff and try to normalize the model
      double current_cutoff = 0.99999999;
      const double cutoff_lower_limit = 1e-19;
    
      bool found_normalization = false;
      int last_suppressed = 0;
      while (!found_normalization && current_cutoff > cutoff_lower_limit)
        {
          // Drop elements below cutoff from normalized contemporaneous Jacobian
          jacob_map_t normalized_contemporaneous_jacobian_above_cutoff;
          int suppressed = 0;
          for (const auto &[eq_and_endo, val] : normalized_contemporaneous_jacobian)
            if (fabs(val) > max(current_cutoff, cutoff))
              normalized_contemporaneous_jacobian_above_cutoff[eq_and_endo] = val;
            else
              suppressed++;
    
          if (suppressed != last_suppressed)
            found_normalization = computeNormalization(normalized_contemporaneous_jacobian_above_cutoff, false);
          last_suppressed = suppressed;
          if (!found_normalization)
            {
              current_cutoff /= 2;
              // In this last case try to normalize with the complete jacobian
              if (current_cutoff <= cutoff_lower_limit)
                found_normalization = computeNormalization(normalized_contemporaneous_jacobian, false);
            }
        }
    
      if (!found_normalization)
        {
          cout << "Normalization failed with cutoff, trying symbolic normalization..." << endl;
          /* If no non-singular normalization can be found, try to find a
             normalization even with a potential singularity.
             TODO: Explain why symbolic_jacobian is not contemporaneous. */
          auto symbolic_jacobian = computeSymbolicJacobian();
          found_normalization = computeNormalization(symbolic_jacobian, true);
        }
    
      if (!found_normalization)
        {
          cerr << "No normalization could be computed. Aborting." << endl;
          exit(EXIT_FAILURE);
        }
    }
    
    ModelTree::jacob_map_t
    ModelTree::evaluateAndReduceJacobian(const eval_context_t &eval_context) const
    {
      jacob_map_t contemporaneous_jacobian;
      for (const auto &[indices, d1] : derivatives[1])
        {
          int deriv_id = indices[1];
          if (getTypeByDerivID(deriv_id) == SymbolType::endogenous)
            {
              int eq = indices[0];
              int symb = getSymbIDByDerivID(deriv_id);
              int var = symbol_table.getTypeSpecificID(symb);
              int lag = getLagByDerivID(deriv_id);
              double val = 0;
              try
                {
                  val = d1->eval(eval_context);
                }
              catch (ExprNode::EvalExternalFunctionException &e)
                {
                  val = 1;
                }
              catch (ExprNode::EvalException &e)
                {
                  cerr << "ERROR: evaluation of Jacobian failed for equation " << eq+1 << " (line " << equations_lineno[eq] << ") and variable " << symbol_table.getName(symb) << "(" << lag << ") [" << symb << "] !" << endl;
                  d1->writeOutput(cerr, ExprNodeOutputType::matlabDynamicModel, {}, {});
                  cerr << endl;
                  exit(EXIT_FAILURE);
                }
              if ((isnan(val) || fabs(val) >= cutoff) && lag == 0)
                contemporaneous_jacobian[{ eq, var }] = val;
            }
        }
    
      return contemporaneous_jacobian;
    }
    
    pair<int, int>
    ModelTree::computePrologueAndEpilogue()
    {
      const int n = equations.size();
    
      /* Initialize “eq_idx_block2orig” and “endo_idx_block2orig” to the identity
         permutation. */
      eq_idx_block2orig.resize(n);
      endo_idx_block2orig.resize(n);
      for (int i = 0; i < n; i++)
        {
          eq_idx_block2orig[i] = i;
          endo_idx_block2orig[endo2eq[i]] = i;
        }
    
      /* Compute incidence matrix, equations in rows, variables in columns. Row
         (resp. column) indices are to be interpreted according to
         “eq_idx_block2orig” (resp. “endo_idx_block2orig”). Stored in row-major
         order. */
      vector<bool> IM(n*n, false);
      for (int i = 0; i < n; i++)
        {
          set<pair<int, int>> endos_and_lags;
          equations[i]->collectEndogenous(endos_and_lags);
          for (auto [endo, lag] : endos_and_lags)
            IM[i * n + endo2eq[endo]] = true;
        }
    
      bool something_has_been_done;
      // Find the prologue equations and place first the AR(1) shock equations first
      int prologue = 0;
      do
        {
          something_has_been_done = false;
          int new_prologue = prologue;
          for (int i = prologue; i < n; i++)
            {
              int nze = 0;
              int k = 0;
              for (int j = new_prologue; j < n; j++)
                if (IM[i * n + j])
                  {
                    nze++;
                    k = j;
                  }
              if (nze == 1)
                {
                  // Swap equations indexed by “new_prologue” and i
                  for (int j = 0; j < n; j++)
                    swap(IM[new_prologue * n + j], IM[i * n + j]);
                  swap(eq_idx_block2orig[new_prologue], eq_idx_block2orig[i]);
    
                  // Swap variables indexed by “new_prologue” and k (in the matching)
                  for (int j = 0; j < n; j++)
                    swap(IM[j * n + new_prologue], IM[j * n + k]);
                  swap(endo_idx_block2orig[new_prologue], endo_idx_block2orig[k]);
    
                  new_prologue++;
                  something_has_been_done = true;
                }
            }
          prologue = new_prologue;
        }
      while (something_has_been_done);
      
      // Find the epilogue equations
      int epilogue = 0;
      do
        {
          something_has_been_done = false;
          int new_epilogue = epilogue;
          for (int i = prologue; i < n - epilogue; i++)
            {
              int nze = 0;
              int k = 0;
              for (int j = prologue; j < n - new_epilogue; j++)
                if (IM[j * n + i])
                  {
                    nze++;
                    k = j;
                  }
              if (nze == 1)
                {
                  for (int j = 0; j < n; j++)
                    swap(IM[(n - 1 - new_epilogue) * n + j], IM[k * n + j]);
                  swap(eq_idx_block2orig[n - 1 - new_epilogue], eq_idx_block2orig[k]);
    
                  for (int j = 0; j < n; j++)
                    swap(IM[j * n + n - 1 - new_epilogue], IM[j * n + i]);
                  swap(endo_idx_block2orig[n - 1 - new_epilogue], endo_idx_block2orig[i]);
    
                  new_epilogue++;
                  something_has_been_done = true;
                }
            }
          epilogue = new_epilogue;
        }
      while (something_has_been_done);
    
      updateReverseVariableEquationOrderings();
    
      return { prologue, epilogue };
    }
    
    void
    ModelTree::equationTypeDetermination(const map<tuple<int, int, int>, expr_t> &first_order_endo_derivatives, int mfs)
    {
      equation_type_and_normalized_equation.clear();
      equation_type_and_normalized_equation.resize(equations.size());
      for (int i = 0; i < static_cast<int>(equations.size()); i++)
        {
          int eq = eq_idx_block2orig[i];
          int var = endo_idx_block2orig[i];
          expr_t lhs = equations[eq]->arg1;
          EquationType Equation_Simulation_Type = EquationType::solve;
          BinaryOpNode *normalized_eq = nullptr;
          if (auto it = first_order_endo_derivatives.find({ eq, var, 0 });
              it != first_order_endo_derivatives.end())
            {
              expr_t derivative = it->second;
              // Determine whether the equation can be evaluated rather than solved
              if (lhs->isVariableNodeEqualTo(SymbolType::endogenous, endo_idx_block2orig[i], 0)
                  && derivative->isNumConstNodeEqualTo(1))
                Equation_Simulation_Type = EquationType::evaluate;
              else
                {
                  set<pair<int, int>> result;
                  derivative->collectEndogenous(result);
                  bool variable_not_in_derivative = result.find({ var, 0 }) == result.end();
    
                  try
                    {
                      normalized_eq = equations[eq]->normalizeEquation(symbol_table.getID(SymbolType::endogenous, var), 0);
                      if ((mfs == 2 && variable_not_in_derivative) || mfs == 3)
                        Equation_Simulation_Type = EquationType::evaluateRenormalized;
                    }
                  catch (ExprNode::NormalizationFailed &e)
                    {
                    }
                }
            }
          equation_type_and_normalized_equation[eq] = { Equation_Simulation_Type, normalized_eq };
        }
    }
    
    void
    ModelTree::computeDynamicStructureOfBlock(int blk)
    {
      vector<pair<int, int>> max_endo_lag_lead(blocks[blk].size, { 0, 0 });
      blocks[blk].max_endo_lag = blocks[blk].max_endo_lead = 0;
      blocks[blk].max_other_endo_lag = blocks[blk].max_other_endo_lead = 0;
      blocks[blk].max_exo_lag = blocks[blk].max_exo_lead = 0;
      blocks[blk].max_exo_det_lag = blocks[blk].max_exo_det_lead = 0;
      for (int eq = 0; eq < blocks[blk].size; eq++)
        {
          set<pair<int, int>> endos_and_lags;
          expr_t e = getBlockEquationExpr(blk, eq);
    
          /* Compute max lags/leads for endogenous. Also fill per-variable structure
             for endos belonging to this block */
          e->collectEndogenous(endos_and_lags);
          for (auto [endo, lag] : endos_and_lags)
            if (endo2block[endo] == blk)
              {
                blocks[blk].max_endo_lag = max(blocks[blk].max_endo_lag, -lag);
                blocks[blk].max_endo_lead = max(blocks[blk].max_endo_lead, lag);
                auto &[max_endo_lag, max_endo_lead] = max_endo_lag_lead[getBlockInitialVariableID(blk, endo)];
                max_endo_lag = max(max_endo_lag, -lag);
                max_endo_lead = max(max_endo_lead, lag);
              }
            else
              {
                blocks[blk].max_other_endo_lag = max(blocks[blk].max_other_endo_lag, -lag);
                blocks[blk].max_other_endo_lead = max(blocks[blk].max_other_endo_lead, lag);
              }
    
          // Compute max lags/leads for exogenous
          blocks[blk].max_exo_lag = max(e->maxExoLag(), blocks[blk].max_exo_lag);
          blocks[blk].max_exo_lead = max(e->maxExoLead(), blocks[blk].max_exo_lead);
    
          // Compute max lags/leads for deterministic exogenous
          set<pair<int, int>> dynvars;
          e->collectDynamicVariables(SymbolType::exogenousDet, dynvars);
          for (auto [symb_id, lag] : dynvars)
            {
              blocks[blk].max_exo_det_lag = max(-lag, blocks[blk].max_exo_det_lag);
              blocks[blk].max_exo_det_lead = max(lag, blocks[blk].max_exo_det_lead);
            }
        }
    
      // Compute max lags/leads over all variables
      blocks[blk].max_lag = max(blocks[blk].max_endo_lag, max(blocks[blk].max_other_endo_lag,
                                                              max(blocks[blk].max_exo_lag,
                                                                  blocks[blk].max_exo_det_lag)));
      blocks[blk].max_lead = max(blocks[blk].max_endo_lead, max(blocks[blk].max_other_endo_lead,
                                                                max(blocks[blk].max_exo_lead,
                                                                    blocks[blk].max_exo_det_lead)));
    
      // Categorize endos that belong to the block
      blocks[blk].n_mixed = blocks[blk].n_forward = blocks[blk].n_backward = blocks[blk].n_static = 0;
      for (int var = 0; var < blocks[blk].size; var++)
        {
          auto [max_lag, max_lead] = max_endo_lag_lead[var];
          if (max_lag != 0 && max_lead != 0)
            blocks[blk].n_mixed++;
          else if (max_lag == 0 && max_lead != 0)
            blocks[blk].n_forward++;
          else if (max_lag != 0 && max_lead == 0)
            blocks[blk].n_backward++;
          else
            blocks[blk].n_static++;
        }
    }
    
    void
    ModelTree::computeSimulationTypeOfBlock(int blk)
    {
      auto &type = blocks[blk].simulation_type;
      if (blocks[blk].max_endo_lag > 0 && blocks[blk].max_endo_lead > 0)
        {
          if (blocks[blk].size == 1)
            type = BlockSimulationType::solveTwoBoundariesSimple;
          else
            type = BlockSimulationType::solveTwoBoundariesComplete;
        }
      else if (blocks[blk].size > 1)
        {
          if (blocks[blk].max_endo_lead > 0)
            type = BlockSimulationType::solveBackwardComplete;
          else
            type = BlockSimulationType::solveForwardComplete;
        }
      else
        {
          bool can_eval = (getBlockEquationType(blk, 0) == EquationType::evaluate
                           || getBlockEquationType(blk, 0) == EquationType::evaluateRenormalized);
          if (blocks[blk].max_endo_lead > 0)
            type = can_eval ? BlockSimulationType::evaluateBackward :
              BlockSimulationType::solveBackwardSimple;
          else
            type = can_eval ? BlockSimulationType::evaluateForward :
              BlockSimulationType::solveForwardSimple;
        }
    }
    
    pair<lag_lead_vector_t, lag_lead_vector_t>
    ModelTree::getVariableLeadLagByBlock() const
    {
      int nb_endo = symbol_table.endo_nbr();
    
      lag_lead_vector_t variable_lag_lead(nb_endo, { 0, 0 }), equation_lag_lead(nb_endo, { 0, 0 });
      for (int eq = 0; eq < nb_endo; eq++)
        {
          set<pair<int, int>> endos_and_lags;
          equations[eq]->collectEndogenous(endos_and_lags);
          for (auto [endo, lag] : endos_and_lags)
            if (endo2block[endo] == eq2block[eq])
              {
                variable_lag_lead[endo].first = max(variable_lag_lead[endo].first, -lag);
                variable_lag_lead[endo].second = max(variable_lag_lead[endo].second, lag);
                equation_lag_lead[eq].first = max(equation_lag_lead[eq].first, -lag);
                equation_lag_lead[eq].second = max(equation_lag_lead[eq].second, lag);
              }
        }
      return { equation_lag_lead, variable_lag_lead };
    }
    
    void
    ModelTree::computeBlockDecomposition(int prologue, int epilogue)
    {
      int nb_var = symbol_table.endo_nbr();
      int nb_simvars = nb_var - prologue - epilogue;
    
      /* Construct the graph representing the dependencies between all
         variables that do not belong to the prologue or the epilogue.
    
         For detecting dependencies between variables, use the symbolic adjacency
         matrix */
      VariableDependencyGraph G(nb_simvars);
      for (const auto &[key, value] : computeSymbolicJacobian())
        {
          auto [eq, endo] = key;
          if (eq_idx_orig2block[eq] >= prologue
              && eq_idx_orig2block[eq] < nb_var - epilogue
              && endo_idx_orig2block[endo] >= prologue
              && endo_idx_orig2block[endo] < nb_var - epilogue
              && eq != endo2eq[endo])
            add_edge(vertex(eq_idx_orig2block[endo2eq[endo]]-prologue, G),
                     vertex(eq_idx_orig2block[eq]-prologue, G), G);
        }
    
      /* Identify the simultaneous blocks. Each simultaneous block is given an
         index, starting from 0, in recursive order */
      auto [num_simblocks, simvar2simblock] = G.sortedStronglyConnectedComponents();
    
      int num_blocks = prologue+num_simblocks+epilogue;
    
      blocks.clear();
      blocks.resize(num_blocks);
      endo2block.resize(nb_var);
      eq2block.resize(nb_var);
    
      // Initialize size and mfs_size for prologue and epilogue, plus eq/endo→block mappings
      for (int blk = 0; blk < num_blocks; blk++)
        if (blk < prologue || blk >= num_blocks-epilogue)
          {
            int var_eq = (blk < prologue ? blk : blk-num_simblocks+nb_simvars);
            blocks[blk].size = 1;
            blocks[blk].mfs_size = 1;
            blocks[blk].first_equation = var_eq;
            endo2block[endo_idx_block2orig[var_eq]] = blk;
            eq2block[eq_idx_block2orig[var_eq]] = blk;
          }
    
      // Initialize size for simultaneous blocks, plus eq/endo→block mappings
      vector<vector<int>> simblock2simvars(num_simblocks);
      for (int i = 0; i < static_cast<int>(simvar2simblock.size()); i++)
        {
          simblock2simvars[simvar2simblock[i]].push_back(i);
          int blk = prologue+simvar2simblock[i];
          blocks[blk].size++;
          endo2block[endo_idx_block2orig[prologue+i]] = blk;
          eq2block[eq_idx_block2orig[prologue+i]] = blk;
        }
    
      // Determine the dynamic structure of each block
      auto [equation_lag_lead, variable_lag_lead] = getVariableLeadLagByBlock();
    
      /* For each simultaneous block, the minimum set of feedback variable is computed.
         Then, the variables within the blocks are reordered so that recursive
         (non-feedback) appear first, to get a sub-recursive block without feedback variables.
         Within each of the two sub-blocks, variables are reordered depending
         on their dynamic status: static first, then backward, mixed and forward. */
    
      /* First, add a loop on vertices which could not be normalized or vertices
         related to lead/lag variables. This forces those vertices to belong to the
         feedback set */
      for (int i = 0; i < nb_simvars; i++)
        if (equation_type_and_normalized_equation[eq_idx_block2orig[i+prologue]].first == EquationType::solve
            || variable_lag_lead[endo_idx_block2orig[i+prologue]].first > 0
            || variable_lag_lead[endo_idx_block2orig[i+prologue]].second > 0
            || equation_lag_lead[eq_idx_block2orig[i+prologue]].first > 0
            || equation_lag_lead[eq_idx_block2orig[i+prologue]].second > 0
            || mfs == 0)
          add_edge(vertex(i, G), vertex(i, G), G);
    
      const vector<int> old_eq_idx_block2orig(eq_idx_block2orig), old_endo_idx_block2orig(endo_idx_block2orig);
      int ordidx = prologue;
      for (int blk = prologue; blk < prologue+num_simblocks; blk++)
        {
          blocks[blk].first_equation = (blk == 0 ? 0 : blocks[blk-1].first_equation + blocks[blk-1].size);
          auto subG = G.extractSubgraph(simblock2simvars[blk-prologue]);
          auto feed_back_vertices = subG.minimalSetOfFeedbackVertices();
          blocks[blk].mfs_size = feed_back_vertices.size();
          auto recursive_vertices = subG.reorderRecursiveVariables(feed_back_vertices);
          auto v_index1 = get(boost::vertex_index1, subG);
    
          const vector<pair<int, int>> dynamic_order{ make_pair(0, 0), make_pair(1, 0),
                                                      make_pair(1, 1), make_pair(0, 1) };
    
          // First the recursive equations conditional on feedback variables
          for (auto max_lag_lead : dynamic_order)
            for (int vtx : recursive_vertices)
              if (int simvar = v_index1[vertex(vtx, subG)];
                  variable_lag_lead[old_endo_idx_block2orig[simvar+prologue]] == max_lag_lead)
                {
                  eq_idx_block2orig[ordidx] = old_eq_idx_block2orig[simvar+prologue];
                  endo_idx_block2orig[ordidx] = old_endo_idx_block2orig[simvar+prologue];
                  ordidx++;
                }
    
          // Then the equations related to the feedback variables
          for (auto max_lag_lead : dynamic_order)
            for (int vtx : feed_back_vertices)
              if (int simvar = v_index1[vertex(vtx, subG)];
                  variable_lag_lead[old_endo_idx_block2orig[simvar+prologue]] == max_lag_lead)
                {
                  eq_idx_block2orig[ordidx] = old_eq_idx_block2orig[simvar+prologue];
                  endo_idx_block2orig[ordidx] = old_endo_idx_block2orig[simvar+prologue];
                  ordidx++;
                }
        }
    
      updateReverseVariableEquationOrderings();
    
      for (int blk = 0; blk < static_cast<int>(blocks.size()); blk++)
        {
          computeDynamicStructureOfBlock(blk);
          computeSimulationTypeOfBlock(blk);
        }
    }
    
    void
    ModelTree::printBlockDecomposition() const
    {
      int largest_block = 0, Nb_SimulBlocks = 0, Nb_feedback_variable = 0;
      int Nb_TotalBlocks = blocks.size();
      for (int block = 0; block < Nb_TotalBlocks; block++)
        if (BlockSimulationType simulation_type = blocks[block].simulation_type;
            simulation_type == BlockSimulationType::solveForwardComplete
            || simulation_type == BlockSimulationType::solveBackwardComplete
            || simulation_type == BlockSimulationType::solveTwoBoundariesComplete)
          {
            Nb_SimulBlocks++;
            if (int size = blocks[block].size;
                size > largest_block)
              {
                largest_block = size;
                Nb_feedback_variable = blocks[block].mfs_size;
              }
          }
    
      int Nb_RecursBlocks = Nb_TotalBlocks - Nb_SimulBlocks;
      cout << Nb_TotalBlocks << " block(s) found:" << endl
           << "  " << Nb_RecursBlocks << " recursive block(s) and " << Nb_SimulBlocks << " simultaneous block(s)." << endl
           << "  the largest simultaneous block has " << largest_block << " equation(s)" << endl
           << "                                 and " << Nb_feedback_variable << " feedback variable(s)." << endl;
    }
    
    void
    ModelTree::reduceBlockDecomposition()
    {
      for (int blk = 1; blk < static_cast<int>(blocks.size()); blk++)
        if (blocks[blk].size == 1)
          {
            /* Try to merge this block with the previous one.
               This is only possible if the two blocks can simply be evaluated
               (in the same direction), and if the merge does not break the
               restrictions on leads/lags. */
            set<pair<int, int>> endos_and_lags;
            getBlockEquationExpr(blk, 0)->collectEndogenous(endos_and_lags);
            bool is_lead = false, is_lag = false;
            for (int var = 0; var < blocks[blk-1].size; var++)
              {
                is_lag = is_lag || endos_and_lags.find({ getBlockVariableID(blk-1, var), -1 }) != endos_and_lags.end();
                is_lead = is_lead || endos_and_lags.find({ getBlockVariableID(blk-1, var), 1 }) != endos_and_lags.end();
              }
    
            if ((blocks[blk-1].simulation_type == BlockSimulationType::evaluateForward
                 && blocks[blk].simulation_type == BlockSimulationType::evaluateForward
                 && !is_lead)
                || (blocks[blk-1].simulation_type == BlockSimulationType::evaluateBackward
                    && blocks[blk].simulation_type == BlockSimulationType::evaluateBackward
                    && !is_lag))
              {
                // Merge the current block into the previous one
                blocks[blk-1].size++;
                blocks[blk-1].mfs_size = blocks[blk-1].size;
                computeDynamicStructureOfBlock(blk-1);
                blocks.erase(blocks.begin()+blk);
                for (auto &b : endo2block)
                  if (b >= blk)
                    b--;
                for (auto &b : eq2block)
                  if (b >= blk)
                    b--;
                blk--;
                continue;
              }
          }
    }
    
    void
    ModelTree::determineLinearBlocks()
    {
      // Note that field “linear” in class BlockInfo defaults to true
      for (int blk = 0; blk < static_cast<int>(blocks.size()); blk++)
        switch (blocks[blk].simulation_type)
          {
          case BlockSimulationType::solveBackwardSimple:
          case BlockSimulationType::solveBackwardComplete:
          case BlockSimulationType::solveForwardSimple:
          case BlockSimulationType::solveForwardComplete:
            for (const auto &[indices, d1] : blocks_derivatives[blk])
              {
                int lag = get<2>(indices);
                if (lag == 0)
                  {
                    set<pair<int, int>> endogenous;
                    d1->collectEndogenous(endogenous);
                    for (int l = 0; l < blocks[blk].size; l++)
                      if (endogenous.find({ endo_idx_block2orig[blocks[blk].first_equation+l], 0 })
                          != endogenous.end())
                        {
                          blocks[blk].linear = false;
                          goto the_end;
                        }
                  }
              }
          the_end:
            break;
          case BlockSimulationType::solveTwoBoundariesComplete:
          case BlockSimulationType::solveTwoBoundariesSimple:
            for (const auto &[indices, d1] : blocks_derivatives[blk])
              {
                int lag = get<2>(indices);
                set<pair<int, int>> endogenous;
                d1->collectEndogenous(endogenous);
                for (int l = 0; l < blocks[blk].size; l++)
                  if (endogenous.find({ endo_idx_block2orig[blocks[blk].first_equation+l], lag })
                      != endogenous.end())
                    {
                      blocks[blk].linear = false;
                      goto the_end2;
                    }
              }
          the_end2:
            break;
          default:
            break;
          }
    }
    
    int
    ModelTree::equation_number() const
    {
      return (equations.size());
    }
    
    void
    ModelTree::writeDerivative(ostream &output, int eq, int symb_id, int lag,
                               ExprNodeOutputType output_type,
                               const temporary_terms_t &temporary_terms) const
    {
      if (auto it = derivatives[1].find({ eq, getDerivID(symb_id, lag) });
          it != derivatives[1].end())
        it->second->writeOutput(output, output_type, temporary_terms, {});
      else
        output << 0;
    }
    
    void
    ModelTree::computeDerivatives(int order, const set<int> &vars)
    {
      assert(order >= 1);
    
      computed_derivs_order = order;
    
      // Do not shrink the vectors, since they have a minimal size of 4 (see constructor)
      derivatives.resize(max(static_cast<size_t>(order+1), derivatives.size()));
      NNZDerivatives.resize(max(static_cast<size_t>(order+1), NNZDerivatives.size()), 0);
    
      // First-order derivatives
      for (int var : vars)
        for (int eq = 0; eq < static_cast<int>(equations.size()); eq++)
          {
            expr_t d1 = equations[eq]->getDerivative(var);
            if (d1 == Zero)
              continue;
            derivatives[1][{ eq, var }] = d1;
            ++NNZDerivatives[1];
          }
    
      // Higher-order derivatives
      for (int o = 2; o <= order; o++)
        for (const auto &[lower_indices, lower_d] : derivatives[o-1])
          for (int var : vars)
            {
              if (lower_indices.back() > var)
                continue;
    
              expr_t d = lower_d->getDerivative(var);
              if (d == Zero)
                continue;
    
              vector<int> indices{lower_indices};
              indices.push_back(var);
              // At this point, indices of endogenous variables are sorted in non-decreasing order
              derivatives[o][indices] = d;
              // We output symmetric elements at order = 2
              if (o == 2 && indices[1] != indices[2])
                NNZDerivatives[o] += 2;
              else
                NNZDerivatives[o]++;
            }
    }
    
    void
    ModelTree::computeTemporaryTerms(bool is_matlab, bool no_tmp_terms)
    {
      /* Collect all model local variables appearing in equations (and only those,
         because printing unused model local variables can lead to a crash,
         see Dynare/dynare#101).
         Then store them in a dedicated structure (temporary_terms_mlv), that will
         be treated as the rest of temporary terms. */
      temporary_terms_mlv.clear();
      set<int> used_local_vars;
      for (auto &equation : equations)
        equation->collectVariables(SymbolType::modelLocalVariable, used_local_vars);
      for (int used_local_var : used_local_vars)
        {
          VariableNode *v = AddVariable(used_local_var);
          temporary_terms_mlv[v] = local_variables_table.find(used_local_var)->second;
        }
    
      // Compute the temporary terms in equations and derivatives
      map<pair<int, int>, temporary_terms_t> temp_terms_map;
      map<expr_t, pair<int, pair<int, int>>> reference_count;
    
      for (auto &equation : equations)
        equation->computeTemporaryTerms({ 0, 0 },
                                        temp_terms_map,
                                        reference_count,
                                        is_matlab);
    
      for (int order = 1; order < static_cast<int>(derivatives.size()); order++)
        for (const auto &it : derivatives[order])
          it.second->computeTemporaryTerms({ 0, order },
                                           temp_terms_map,
                                           reference_count,
                                           is_matlab);
    
      /* If the user has specified the notmpterms option, clear all temporary
         terms, except those that correspond to external functions (since they are
         not optional) */
      if (no_tmp_terms)
        for (auto &it : temp_terms_map)
          // The following loop can be simplified with std::erase_if() in C++20
          for (auto it2 = it.second.begin(); it2 != it.second.end();)
            if (!dynamic_cast<AbstractExternalFunctionNode *>(*it2))
              it2 = it.second.erase(it2);
            else
              ++it2;
    
      // Fill the structures
      temporary_terms_derivatives.clear();
      temporary_terms_derivatives.resize(derivatives.size());
      for (int order = 0; order < static_cast<int>(derivatives.size()); order++)
        temporary_terms_derivatives[order] = move(temp_terms_map[{ 0, order }]);
    
      // Compute indices in MATLAB/Julia vector
      int idx = 0;
      for (auto [mlv, value] : temporary_terms_mlv)
        temporary_terms_idxs[mlv] = idx++;
      for (int order = 0; order < static_cast<int>(derivatives.size()); order++)
        for (auto it : temporary_terms_derivatives[order])
          temporary_terms_idxs[it] = idx++;
    }
    
    void
    ModelTree::computeBlockTemporaryTerms()
    {
      int nb_blocks = blocks.size();
      blocks_temporary_terms.resize(nb_blocks);
    
      map<expr_t, tuple<int, int, int>> reference_count;
      for (int blk = 0; blk < nb_blocks; blk++)
        {
          blocks_temporary_terms[blk].resize(blocks[blk].size + 1);
          for (int eq = 0; eq < blocks[blk].size; eq++)
            {
              if (eq < blocks[blk].getRecursiveSize() && isBlockEquationRenormalized(blk, eq))
                getBlockEquationRenormalizedExpr(blk, eq)->computeBlockTemporaryTerms(blk, eq, blocks_temporary_terms, reference_count);
              else
                getBlockEquationExpr(blk, eq)->computeBlockTemporaryTerms(blk, eq, blocks_temporary_terms, reference_count);
            }
          for (const auto &[ignore, d] : blocks_derivatives[blk])
            d->computeBlockTemporaryTerms(blk, blocks[blk].size, blocks_temporary_terms, reference_count);
    
          additionalBlockTemporaryTerms(blk, blocks_temporary_terms, reference_count);
        }
    
      // Compute indices in the temporary terms vector
      int idx = 0;
      blocks_temporary_terms_idxs.clear();
      for (auto &blk_tt : blocks_temporary_terms)
        for (auto &eq_tt : blk_tt)
          for (auto tt : eq_tt)
            blocks_temporary_terms_idxs[tt] = idx++;
    }
    
    void
    ModelTree::additionalBlockTemporaryTerms(int blk,
                                             vector<vector<temporary_terms_t>> &blocks_temporary_terms,
                                             map<expr_t, tuple<int, int, int>> &reference_count) const
    {
    }
    
    void
    ModelTree::writeModelLocalVariableTemporaryTerms(temporary_terms_t &temp_term_union,
                                                     const temporary_terms_idxs_t &tt_idxs,
                                                     ostream &output, ExprNodeOutputType output_type,
                                                     deriv_node_temp_terms_t &tef_terms) const
    {
      temporary_terms_t tto;
      for (auto [mlv, value] : temporary_terms_mlv)
        tto.insert(mlv);
    
      for (auto [mlv, value] : temporary_terms_mlv)
        {
          value->writeExternalFunctionOutput(output, output_type, temp_term_union, tt_idxs, tef_terms);
    
          if (isJuliaOutput(output_type))
            output << "    @inbounds const ";
    
          mlv->writeOutput(output, output_type, tto, tt_idxs, tef_terms);
          output << " = ";
          value->writeOutput(output, output_type, temp_term_union, tt_idxs, tef_terms);
    
          if (isCOutput(output_type) || isMatlabOutput(output_type))
            output << ";";
          output << endl;
    
          /* We put in temp_term_union the VariableNode corresponding to the MLV,
             not its definition, so that when equations use the MLV,
             T(XXX) is printed instead of the MLV name */
          temp_term_union.insert(mlv);
        }
    }
    
    void
    ModelTree::writeTemporaryTerms(const temporary_terms_t &tt,
                                   temporary_terms_t &temp_term_union,
                                   const temporary_terms_idxs_t &tt_idxs,
                                   ostream &output, ExprNodeOutputType output_type, deriv_node_temp_terms_t &tef_terms) const
    {
      for (auto it : tt)
        {
          if (dynamic_cast<AbstractExternalFunctionNode *>(it))
            it->writeExternalFunctionOutput(output, output_type, temp_term_union, tt_idxs, tef_terms);
    
          if (isJuliaOutput(output_type))
            output << "    @inbounds ";
    
          it->writeOutput(output, output_type, tt, tt_idxs, tef_terms);
          output << " = ";
          it->writeOutput(output, output_type, temp_term_union, tt_idxs, tef_terms);
    
          if (isCOutput(output_type) || isMatlabOutput(output_type))
            output << ";";
          output << endl;
    
          temp_term_union.insert(it);
        }
    }
    
    void
    ModelTree::writeJsonTemporaryTerms(const temporary_terms_t &tt,
                                       temporary_terms_t &temp_term_union,
                                       ostream &output,
                                       deriv_node_temp_terms_t &tef_terms, const string &concat) const
    {
      // Local var used to keep track of temp nodes already written
      bool wrote_term = false;
      temporary_terms_t tt2 = temp_term_union;
    
      output << R"("external_functions_temporary_terms_)" << concat << R"(": [)";
      for (auto it : tt)
        {
          if (dynamic_cast<AbstractExternalFunctionNode *>(it))
            {
              if (wrote_term)
                output << ", ";
              vector<string> efout;
              it->writeJsonExternalFunctionOutput(efout, tt2, tef_terms);
              for (auto it1 = efout.begin(); it1 != efout.end(); ++it1)
                {
                  if (it1 != efout.begin())
                    output << ", ";
                  output << *it1;
                }
              wrote_term = true;
            }
          tt2.insert(it);
        }
    
      wrote_term = false;
      output << "]"
             << R"(, "temporary_terms_)" << concat << R"(": [)";
      for (const auto &it : tt)
        {
          if (wrote_term)
            output << ", ";
          output << R"({"temporary_term": ")";
          it->writeJsonOutput(output, tt, tef_terms);
          output << R"(")"
                 << R"(, "value": ")";
          it->writeJsonOutput(output, temp_term_union, tef_terms);
          output << R"("})" << endl;
          wrote_term = true;
    
          temp_term_union.insert(it);
        }
      output << "]";
    }
    
    void
    ModelTree::fixNestedParenthesis(ostringstream &output, map<string, string> &tmp_paren_vars, bool &message_printed) const
    {
      string str = output.str();
      if (!testNestedParenthesis(str))
        return;
      int open = 0;
      int first_open_paren = 0;
      int matching_paren = 0;
      bool hit_limit = false;
      int i1 = 0;
      for (size_t i = 0; i < str.length(); i++)
        {
          if (str.at(i) == '(')
            {
              if (open == 0)
                first_open_paren = i;
              open++;
            }
          else if (str.at(i) == ')')
            {
              open--;
              if (open == 0)
                matching_paren = i;
            }
          if (open > 32)
            hit_limit = true;
    
          if (hit_limit && open == 0)
            {
              if (!message_printed)
                {
                  cerr << "Warning: A .m file created by Dynare will have more than 32 nested parenthesis. MATLAB cannot support this. " << endl
                       << "         We are going to modify, albeit inefficiently, this output to have fewer than 32 nested parenthesis. " << endl
                       << "         It would hence behoove you to use the use_dll option of the model block to circumnavigate this problem." << endl
                       << "         If you have not yet set up a compiler on your system, see the MATLAB documentation for doing so." << endl
                       << "         For Windows, see: https://www.mathworks.com/help/matlab/matlab_external/install-mingw-support-package.html" << endl << endl;
                  message_printed = true;
                }
              string str1 = str.substr(first_open_paren, matching_paren - first_open_paren + 1);
              string repstr, varname;
              while (testNestedParenthesis(str1))
                {
                  size_t open_paren_idx = string::npos;
                  size_t match_paren_idx = string::npos;
                  size_t last_open_paren = string::npos;
                  for (size_t j = 0; j < str1.length(); j++)
                    {
                      if (str1.at(j) == '(')
                        {
                          // don't match, e.g. y(1)
                          if (size_t idx = str1.find_last_of("*/-+", j - 1);
                              j == 0 || (idx != string::npos && idx == j - 1))
                            open_paren_idx = j;
                          last_open_paren = j;
                        }
                      else if (str1.at(j) == ')')
                        {
                          // don't match, e.g. y(1)
                          if (size_t idx = str1.find_last_not_of("0123456789", j - 1);
                              idx != string::npos && idx != last_open_paren)
                            match_paren_idx = j;
                        }
    
                      if (open_paren_idx != string::npos && match_paren_idx != string::npos)
                        {
                          string val = str1.substr(open_paren_idx, match_paren_idx - open_paren_idx + 1);
                          if (auto it = tmp_paren_vars.find(val);
                              it == tmp_paren_vars.end())
                            {
                              ostringstream ptvstr;
                              ptvstr << i1++;
                              varname = "paren32_tmp_var_" + ptvstr.str();
                              repstr = repstr + varname + " = " + val + ";\n";
                              tmp_paren_vars[val] = varname;
                            }
                          else
                            varname = it->second;
                          str1.replace(open_paren_idx, match_paren_idx - open_paren_idx + 1, varname);
                          break;
                        }
                    }
                }
              if (auto it = tmp_paren_vars.find(str1);
                  it == tmp_paren_vars.end())
                {
                  ostringstream ptvstr;
                  ptvstr << i1++;
                  varname = "paren32_tmp_var_" + ptvstr.str();
                  repstr = repstr + varname + " = " + str1 + ";\n";
                }
              else
                varname = it->second;
              str.replace(first_open_paren, matching_paren - first_open_paren + 1, varname);
              size_t insertLoc = str.find_last_of("\n", first_open_paren);
              str.insert(insertLoc + 1, repstr);
              hit_limit = false;
              i = -1;
              first_open_paren = matching_paren = open = 0;
            }
        }
      output.str(str);
    }
    
    bool
    ModelTree::testNestedParenthesis(const string &str) const
    {
      int open = 0;
      for (char i : str)
        {
          if (i == '(')
            open++;
          else if (i == ')')
            open--;
          if (open > 32)
            return true;
        }
      return false;
    }
    
    void
    ModelTree::compileTemporaryTerms(ostream &code_file, unsigned int &instruction_number, bool dynamic, bool steady_dynamic, temporary_terms_t &temporary_terms_union, const temporary_terms_idxs_t &temporary_terms_idxs) const
    {
      // To store the functions that have already been written in the form TEF* = ext_fun();
      deriv_node_temp_terms_t tef_terms;
      for (auto [tt, idx] : temporary_terms_idxs)
        {
          if (dynamic_cast<AbstractExternalFunctionNode *>(tt))
            tt->compileExternalFunctionOutput(code_file, instruction_number, false, temporary_terms_union, temporary_terms_idxs, dynamic, steady_dynamic, tef_terms);
    
          FNUMEXPR_ fnumexpr(ExpressionType::TemporaryTerm, idx);
          fnumexpr.write(code_file, instruction_number);
          tt->compile(code_file, instruction_number, false, temporary_terms_union, temporary_terms_idxs, dynamic, steady_dynamic, tef_terms);
          if (dynamic)
            {
              FSTPT_ fstpt(idx);
              fstpt.write(code_file, instruction_number);
            }
          else
            {
              FSTPST_ fstpst(idx);
              fstpst.write(code_file, instruction_number);
            }
        }
    }
    
    void
    ModelTree::writeJsonModelLocalVariables(ostream &output, bool write_tef_terms, deriv_node_temp_terms_t &tef_terms) const
    {
      /* Collect all model local variables appearing in equations, and print only
         them. Printing unused model local variables can lead to a crash (see
         ticket #101). */
      set<int> used_local_vars;
    
      for (auto equation : equations)
        equation->collectVariables(SymbolType::modelLocalVariable, used_local_vars);
    
      output << R"("model_local_variables": [)";
      bool printed = false;
      for (int id : local_variables_vector)
        if (used_local_vars.find(id) != used_local_vars.end())
          {
            if (printed)
              output << ", ";
            else
              printed = true;
    
            expr_t value = local_variables_table.find(id)->second;
            if (write_tef_terms)
              {
                vector<string> efout;
                value->writeJsonExternalFunctionOutput(efout, {}, tef_terms);
                for (auto it1 = efout.begin(); it1 != efout.end(); ++it1)
                  {
                    if (it1 != efout.begin())
                      output << ", ";
                    output << *it1;
                  }
    
                if (!efout.empty())
                  output << ", ";
              }
    
            output << R"({"variable": ")" << symbol_table.getName(id)
                   << R"(", "value": ")";
            value->writeJsonOutput(output, {}, tef_terms);
            output << R"("})" << endl;
          }
      output << "]";
    }
    
    void
    ModelTree::writeModelEquations(ostream &output, ExprNodeOutputType output_type) const
    {
      temporary_terms_t tt;
      temporary_terms_idxs_t ttidxs;
      writeModelEquations(output, output_type, tt);
    }
    
    void
    ModelTree::writeModelEquations(ostream &output, ExprNodeOutputType output_type,
                                   const temporary_terms_t &temporary_terms) const
    {
      for (int eq = 0; eq < static_cast<int>(equations.size()); eq++)
        {
          BinaryOpNode *eq_node = equations[eq];
          expr_t lhs = eq_node->arg1;
          expr_t rhs = eq_node->arg2;
    
          // Test if the right hand side of the equation is empty.
          double vrhs = 1.0;
          try
            {
              vrhs = rhs->eval(eval_context_t());
            }
          catch (ExprNode::EvalException &e)
            {
            }
    
          if (vrhs != 0) // The right hand side of the equation is not empty ==> residual=lhs-rhs;
            if (isJuliaOutput(output_type))
              {
                output << "    @inbounds residual" << LEFT_ARRAY_SUBSCRIPT(output_type)
                       << eq + ARRAY_SUBSCRIPT_OFFSET(output_type)
                       << RIGHT_ARRAY_SUBSCRIPT(output_type)
                       << " = (";
                lhs->writeOutput(output, output_type, temporary_terms, temporary_terms_idxs);
                output << ") - (";
                rhs->writeOutput(output, output_type, temporary_terms, temporary_terms_idxs);
                output << ")" << endl;
              }
            else
              {
                output << "lhs = ";
                lhs->writeOutput(output, output_type, temporary_terms, temporary_terms_idxs);
                output << ";" << endl
                       << "rhs = ";
                rhs->writeOutput(output, output_type, temporary_terms, temporary_terms_idxs);
                output << ";" << endl
                       << "residual" << LEFT_ARRAY_SUBSCRIPT(output_type)
                       << eq + ARRAY_SUBSCRIPT_OFFSET(output_type)
                       << RIGHT_ARRAY_SUBSCRIPT(output_type)
                       << " = lhs - rhs;" << endl;
              }
          else // The right hand side of the equation is empty ==> residual=lhs;
            {
              if (isJuliaOutput(output_type))
                output << "    @inbounds ";
              output << "residual" << LEFT_ARRAY_SUBSCRIPT(output_type)
                     << eq + ARRAY_SUBSCRIPT_OFFSET(output_type)
                     << RIGHT_ARRAY_SUBSCRIPT(output_type)
                     << " = ";
              lhs->writeOutput(output, output_type, temporary_terms, temporary_terms_idxs);
              output << ";" << endl;
            }
        }
    }
    
    void
    ModelTree::compileModelEquations(ostream &code_file, unsigned int &instruction_number, bool dynamic, bool steady_dynamic, const temporary_terms_t &temporary_terms_union, const temporary_terms_idxs_t &temporary_terms_idxs) const
    {
      for (int eq = 0; eq < static_cast<int>(equations.size()); eq++)
        {
          BinaryOpNode *eq_node = equations[eq];
          expr_t lhs = eq_node->arg1;
          expr_t rhs = eq_node->arg2;
          FNUMEXPR_ fnumexpr(ExpressionType::ModelEquation, eq);
          fnumexpr.write(code_file, instruction_number);
          // Test if the right hand side of the equation is empty.
          double vrhs = 1.0;
          try
            {
              vrhs = rhs->eval(eval_context_t());
            }
          catch (ExprNode::EvalException &e)
            {
            }
    
          if (vrhs != 0) // The right hand side of the equation is not empty ==> residual=lhs-rhs;
            {
              lhs->compile(code_file, instruction_number, false, temporary_terms_union, temporary_terms_idxs, dynamic, steady_dynamic);
              rhs->compile(code_file, instruction_number, false, temporary_terms_union, temporary_terms_idxs, dynamic, steady_dynamic);
    
              FBINARY_ fbinary{static_cast<int>(BinaryOpcode::minus)};
              fbinary.write(code_file, instruction_number);
    
              FSTPR_ fstpr(eq);
              fstpr.write(code_file, instruction_number);
            }
          else // The right hand side of the equation is empty ==> residual=lhs;
            {
              lhs->compile(code_file, instruction_number, false, temporary_terms_union, temporary_terms_idxs, dynamic, steady_dynamic);
              FSTPR_ fstpr(eq);
              fstpr.write(code_file, instruction_number);
            }
        }
    }
    
    void
    ModelTree::writeBytecodeBinFile(const string &filename, int &u_count_int, bool &file_open,
                                    bool is_two_boundaries) const
    {
      int j;
      std::ofstream SaveCode;
      if (file_open)
        SaveCode.open(filename, ios::out | ios::in | ios::binary | ios::ate);
      else
        SaveCode.open(filename, ios::out | ios::binary);
      if (!SaveCode.is_open())
        {
          cerr << R"(Error : Can't open file ")" << filename << R"(" for writing)" << endl;
          exit(EXIT_FAILURE);
        }
      u_count_int = 0;
      for (const auto & [indices, d1] : derivatives[1])
        {
          int deriv_id = indices[1];
          if (getTypeByDerivID(deriv_id) == SymbolType::endogenous)
            {
              int eq = indices[0];
              int symb = getSymbIDByDerivID(deriv_id);
              int var = symbol_table.getTypeSpecificID(symb);
              int lag = getLagByDerivID(deriv_id);
              SaveCode.write(reinterpret_cast<char *>(&eq), sizeof(eq));
              int varr = var + lag * symbol_table.endo_nbr();
              SaveCode.write(reinterpret_cast<char *>(&varr), sizeof(varr));
              SaveCode.write(reinterpret_cast<char *>(&lag), sizeof(lag));
              int u = u_count_int + symbol_table.endo_nbr();
              SaveCode.write(reinterpret_cast<char *>(&u), sizeof(u));
              u_count_int++;
            }
        }
      if (is_two_boundaries)
        u_count_int += symbol_table.endo_nbr();
      for (j = 0; j < symbol_table.endo_nbr(); j++)
        SaveCode.write(reinterpret_cast<char *>(&j), sizeof(j));
      for (j = 0; j < symbol_table.endo_nbr(); j++)
        SaveCode.write(reinterpret_cast<char *>(&j), sizeof(j));
      SaveCode.close();
    }
    
    void
    ModelTree::writeLatexModelFile(const string &mod_basename, const string &latex_basename, ExprNodeOutputType output_type, bool write_equation_tags) const
    {
      filesystem::create_directories(mod_basename + "/latex");
    
      ofstream output, content_output;
      string filename = mod_basename + "/latex/" + latex_basename + ".tex";
      string content_filename = mod_basename + "/latex/" + latex_basename + "_content" + ".tex";
      output.open(filename, ios::out | ios::binary);
      if (!output.is_open())
        {
          cerr << "ERROR: Can't open file " << filename << " for writing" << endl;
          exit(EXIT_FAILURE);
        }
    
      content_output.open(content_filename, ios::out | ios::binary);
      if (!content_output.is_open())
        {
          cerr << "ERROR: Can't open file " << content_filename << " for writing" << endl;
          exit(EXIT_FAILURE);
        }
    
      output << R"(\documentclass[10pt,a4paper]{article})" << endl
             << R"(\usepackage[landscape]{geometry})" << endl
             << R"(\usepackage{fullpage})" << endl
             << R"(\usepackage{amsfonts})" << endl
             << R"(\usepackage{breqn})" << endl
             << R"(\begin{document})" << endl
             << R"(\footnotesize)" << endl;
    
      // Write model local variables
      for (int id : local_variables_vector)
        {
          expr_t value = local_variables_table.find(id)->second;
    
          content_output << R"(\begin{dmath*})" << endl
                         << symbol_table.getTeXName(id) << " = ";
          // Use an empty set for the temporary terms
          value->writeOutput(content_output, output_type);
          content_output << endl << R"(\end{dmath*})" << endl;
        }
    
      for (int eq = 0; eq < static_cast<int>(equations.size()); eq++)
        {
          content_output << "% Equation " << eq + 1 << endl;
          if (write_equation_tags)
            equation_tags.writeLatexOutput(content_output, eq);
    
          content_output << R"(\begin{dmath})" << endl;
          // Here it is necessary to cast to superclass ExprNode, otherwise the overloaded writeOutput() method is not found
          dynamic_cast<ExprNode *>(equations[eq])->writeOutput(content_output, output_type);
          content_output << endl << R"(\end{dmath})" << endl;
        }
    
      output << R"(\include{)" << latex_basename + "_content" << "}" << endl
             << R"(\end{document})" << endl;
    
      output.close();
      content_output.close();
    }
    
    void
    ModelTree::addEquation(expr_t eq, int lineno)
    {
      auto beq = dynamic_cast<BinaryOpNode *>(eq);
      assert(beq && beq->op_code == BinaryOpcode::equal);
    
      equations.push_back(beq);
      equations_lineno.push_back(lineno);
    }
    
    void
    ModelTree::findConstantEquationsWithoutMcpTag(map<VariableNode *, NumConstNode *> &subst_table) const
    {
      for (size_t i = 0; i < equations.size(); i++)
        if (auto tags = getEquationTags(i);
            tags.find("mcp") == tags.end())
          equations[i]->findConstantEquations(subst_table);
    }
    
    void
    ModelTree::addEquation(expr_t eq, int lineno, const map<string, string> &eq_tags)
    {
      equation_tags.add(equations.size(), eq_tags);
      addEquation(eq, lineno);
    }
    
    void
    ModelTree::addAuxEquation(expr_t eq)
    {
      auto beq = dynamic_cast<BinaryOpNode *>(eq);
      assert(beq && beq->op_code == BinaryOpcode::equal);
    
      aux_equations.push_back(beq);
    }
    
    void
    ModelTree::addTrendVariables(const vector<int> &trend_vars, expr_t growth_factor) noexcept(false)
    {
      for (int id : trend_vars)
        if (trend_symbols_map.find(id) != trend_symbols_map.end())
          throw TrendException(symbol_table.getName(id));
        else
          trend_symbols_map[id] = growth_factor;
    }
    
    void
    ModelTree::addNonstationaryVariables(const vector<int> &nonstationary_vars, bool log_deflator, expr_t deflator) noexcept(false)
    {
      for (int id : nonstationary_vars)
        if (nonstationary_symbols_map.find(id) != nonstationary_symbols_map.end())
          throw TrendException(symbol_table.getName(id));
        else
          nonstationary_symbols_map[id] = { log_deflator, deflator };
    }
    
    void
    ModelTree::initializeVariablesAndEquations()
    {
      for (size_t j = 0; j < equations.size(); j++)
        eq_idx_block2orig.push_back(j);
    
      for (int j = 0; j < symbol_table.endo_nbr(); j++)
        endo_idx_block2orig.push_back(j);
    }
    
    void
    ModelTree::set_cutoff_to_zero()
    {
      cutoff = 0;
    }
    
    void
    ModelTree::jacobianHelper(ostream &output, int eq_nb, int col_nb, ExprNodeOutputType output_type) const
    {
      if (isJuliaOutput(output_type))
        output << "    @inbounds ";
      output << "g1" << LEFT_ARRAY_SUBSCRIPT(output_type);
      if (isMatlabOutput(output_type) || isJuliaOutput(output_type))
        output << eq_nb + 1 << "," << col_nb + 1;
      else
        output << eq_nb + col_nb *equations.size();
      output << RIGHT_ARRAY_SUBSCRIPT(output_type);
    }
    
    void
    ModelTree::computeParamsDerivatives(int paramsDerivsOrder)
    {
      assert(paramsDerivsOrder >= 1);
    
      set<int> deriv_id_set;
      addAllParamDerivId(deriv_id_set);
    
      // First-order derivatives w.r.t. params
      for (int param : deriv_id_set)
        {
          for (int eq = 0; eq < static_cast<int>(equations.size()); eq++)
            {
              expr_t d = equations[eq]->getDerivative(param);
              if (d == Zero)
                continue;
              params_derivatives[{ 0, 1 }][{ eq, param }] = d;
            }
    
          for (int endoOrd = 1; endoOrd < static_cast<int>(derivatives.size()); endoOrd++)
            for (const auto &[lower_indices, lower_d] : derivatives[endoOrd])
              {
                expr_t d = lower_d->getDerivative(param);
                if (d == Zero)
                  continue;
                vector<int> indices{lower_indices};
                indices.push_back(param);
                params_derivatives[{ endoOrd, 1 }][indices] = d;
              }
        }
    
      // Higher-order derivatives w.r.t. parameters
      for (int endoOrd = 0; endoOrd < static_cast<int>(derivatives.size()); endoOrd++)
        for (int paramOrd = 2; paramOrd <= paramsDerivsOrder; paramOrd++)
          for (const auto &[lower_indices, lower_d] : params_derivatives[{ endoOrd, paramOrd-1 }])
            for (int param : deriv_id_set)
              {
                if (lower_indices.back() > param)
                  continue;
    
                expr_t d = lower_d->getDerivative(param);
                if (d == Zero)
                  continue;
                vector<int> indices{lower_indices};
                indices.push_back(param);
                // At this point, indices of both endogenous and parameters are sorted in non-decreasing order
                params_derivatives[{ endoOrd, paramOrd }][indices] = d;
              }
    }
    
    void
    ModelTree::computeParamsDerivativesTemporaryTerms()
    {
      map<expr_t, pair<int, pair<int, int>>> reference_count;
    
      /* The temp terms should be constructed in the same order as the for loops in
         {Static,Dynamic}Model::write{Json,}ParamsDerivativesFile() */
      params_derivs_temporary_terms.clear();
      for (const auto &[order, derivs] : params_derivatives)
        for (const auto &[indices, d] : derivs)
          d->computeTemporaryTerms(order, params_derivs_temporary_terms,
                                   reference_count, true);
    
      int idx = 0;
      for (auto &[mlv, value] : temporary_terms_mlv)
        params_derivs_temporary_terms_idxs[mlv] = idx++;
      for (const auto &[order, tts] : params_derivs_temporary_terms)
        for (const auto &tt : tts)
          params_derivs_temporary_terms_idxs[tt] = idx++;
    }
    
    bool
    ModelTree::isNonstationary(int symb_id) const
    {
      return nonstationary_symbols_map.find(symb_id) != nonstationary_symbols_map.end();
    }
    
    void
    ModelTree::writeJsonModelEquations(ostream &output, bool residuals) const
    {
      if (residuals)
        output << endl << R"("residuals":[)" << endl;
      else
        output << endl << R"("model":[)" << endl;
      for (int eq = 0; eq < static_cast<int>(equations.size()); eq++)
        {
          if (eq > 0)
            output << ", ";
    
          BinaryOpNode *eq_node = equations[eq];
          expr_t lhs = eq_node->arg1;
          expr_t rhs = eq_node->arg2;
    
          if (residuals)
            {
              output << R"({"residual": {)"
                     << R"("lhs": ")";
              lhs->writeJsonOutput(output, {}, {});
              output << R"(")";
    
              output << R"(, "rhs": ")";
              rhs->writeJsonOutput(output, {}, {});
              output << R"(")";
              try
                {
                  // Test if the right hand side of the equation is empty.
                  if (rhs->eval({}) != 0)
                    {
                      output << R"(, "rhs": ")";
                      rhs->writeJsonOutput(output, {}, {});
                      output << R"(")";
                    }
                }
              catch (ExprNode::EvalException &e)
                {
                }
              output << "}";
            }
          else
            {
              output << R"({"lhs": ")";
              lhs->writeJsonOutput(output, {}, {});
              output << R"(", "rhs": ")";
              rhs->writeJsonOutput(output, {}, {});
              output << R"(")"
                     << R"(, "line": )" << equations_lineno[eq];
    
              if (auto eqtags = getEquationTags(eq);
                  !eqtags.empty())
                {
                  output << R"(, "tags": {)";
                  int i = 0;
                  for (const auto &[name, value] : eqtags)
                    {
                      if (i != 0)
                        output << ", ";
                      output << R"(")" << name << R"(": ")" << value << R"(")";
                      i++;
                    }
                  output << "}";
                  eqtags.clear();
                }
            }
          output << "}" << endl;
        }
      output << endl << "]" << endl;
    }
    
    string
    ModelTree::matlab_arch(const string &mexext)
    {
      if (mexext == "mexglx")
        return "glnx86";
      else if (mexext == "mexa64")
        return "glnxa64";
      if (mexext == "mexw32")
        return "win32";
      else if (mexext == "mexw64")
        return "win64";
      else if (mexext == "mexmaci")
        {
          cerr << "32-bit MATLAB not supported on macOS" << endl;
          exit(EXIT_FAILURE);
        }
      else if (mexext == "mexmaci64")
        return "maci64";
      else
        {
          cerr << "ERROR: 'mexext' option to preprocessor incorrectly set, needed with 'use_dll'" << endl;
          exit(EXIT_FAILURE);
        }
    }
    
    #ifdef __APPLE__
    string
    ModelTree::findGccOnMacos()
    {
      const string macos_gcc_version{"11"}; // doc/manual/source/installation-and-configuration.rst
                                            // should be updated when this is changed
      char dynare_preprocessor_path[PATH_MAX];
      uint32_t size = PATH_MAX;
      string local_gcc_path;
      if (_NSGetExecutablePath(dynare_preprocessor_path, &size) == 0)
        {
          string s = dynare_preprocessor_path;
          local_gcc_path = s.substr(0, s.find_last_of("/")) + "/../.brew/bin/gcc-" + macos_gcc_version;
        }
    
      if (filesystem::exists(local_gcc_path))
        return local_gcc_path;
      else if (string global_gcc_path = "/usr/local/bin/gcc-" + macos_gcc_version;
               filesystem::exists(global_gcc_path))
        return global_gcc_path;
      else
        {
          cerr << "ERROR: You must install gcc-" << macos_gcc_version
               << " on your system before using the `use_dll` option of Dynare. "
               << "If using MATLAB, you can do this via the Dynare installation package. If using Octave, you should run `brew install gcc-" << macos_gcc_version << "` in a terminal." << endl;
          exit(EXIT_FAILURE);
        }
    }
    #endif
    
    void
    ModelTree::compileMEX(const string &basename, const string &funcname, const string &mexext, const vector<filesystem::path> &src_files, const filesystem::path &matlabroot, const filesystem::path &dynareroot) const
    {
      const string opt_flags = "-O3 -g0 --param ira-max-conflict-table-size=1 -fno-forward-propagate -fno-gcse -fno-dce -fno-dse -fno-tree-fre -fno-tree-pre -fno-tree-cselim -fno-tree-dse -fno-tree-dce -fno-tree-pta -fno-gcse-after-reload";
    
      filesystem::path compiler;
      ostringstream flags;
      string libs;
    
      if (matlabroot.empty())
        {
          cerr << "ERROR: 'matlabroot' option to preprocessor is not set, needed with 'use_dll'" << endl;
          exit(EXIT_FAILURE);
        }
    
      if (mexext == "mex")
        {
          // Octave
          compiler = matlabroot / "bin" / "mkoctfile";
          flags << "--mex";
    #ifdef __APPLE__
          /* On macOS, enforce GCC, otherwise Clang will be used, and it does not
             accept our custom optimization flags (see dynare#1797) */
          string gcc_path = findGccOnMacos();
          if (setenv("CC", gcc_path.c_str(), 1) != 0)
            {
              cerr << "Can't set CC environment variable" << endl;
              exit(EXIT_FAILURE);
            }
          // We also define CXX, because that is used for linking
          if (setenv("CXX", gcc_path.c_str(), 1) != 0)
            {
              cerr << "Can't set CXX environment variable" << endl;
              exit(EXIT_FAILURE);
            }
    #endif
        }
      else
        {
          // MATLAB
          compiler = "gcc";
          string arch = matlab_arch(mexext);
          auto include_dir = matlabroot / "extern" / "include";
          flags << "-I " << include_dir;
          auto bin_dir = matlabroot / "bin" / arch;
          flags << " -L " << bin_dir;
          flags << " -fexceptions -DNDEBUG";
          libs = "-lmex -lmx";
          if (mexext == "mexa64")
            {
              // GNU/Linux
              flags << " -D_GNU_SOURCE -fPIC -pthread"
                    << " -shared -Wl,--no-undefined -Wl,-rpath-link," << bin_dir;
              libs += " -lm";
            }
          else if (mexext == "mexw64")
            {
              // Windows
              flags << " -static-libgcc -shared";
              // Put the MinGW environment shipped with Dynare in the path
              auto mingwpath = dynareroot / "mingw64" / "bin";
              string newpath = "PATH=" + mingwpath.string() + ';' + string{getenv("PATH")};
              /* We can’t use setenv() since it is not available on MinGW. Note
                that putenv() seems to make a copy of the string on MinGW, contrary
                to what is done on GNU/Linux and macOS. */
              if (putenv(const_cast<char *>(newpath.c_str())) != 0)
                {
                  cerr << "Can't set PATH" << endl;
                  exit(EXIT_FAILURE);
                }
            }
    #ifdef __APPLE__
          else if (mexext == "mexmaci64")
            {
              compiler = findGccOnMacos();
              flags << " -fno-common -Wl,-twolevel_namespace -undefined error -bundle";
              libs += " -lm";
            }
    #endif
          else
            {
              cerr << "ERROR: unsupported value '" << mexext << "' for 'mexext' option" << endl;
              exit(EXIT_FAILURE);
            }
        }
    
      filesystem::path mex_dir{"+" + basename};
      filesystem::path binary{mex_dir / (funcname + "." + mexext)};
    
      ostringstream cmd;
    
    #ifdef _WIN32
      /* On Windows, system() hands the command over to "cmd.exe /C". We need to
         enclose the whole command line within double quotes if we want the inner
         quotes to be correctly handled. See "cmd /?" for more details. */
      cmd << '"';
    #endif
    
      if (user_set_compiler.empty())
        cmd << compiler << " ";
      else
        if (!filesystem::exists(user_set_compiler))
          {
            cerr << "Error: The specified compiler '" << user_set_compiler << "' cannot be found on your system" << endl;
            exit(EXIT_FAILURE);
          }
        else
          cmd << user_set_compiler << " ";
    
      if (user_set_subst_flags.empty())
        cmd << opt_flags << " " << flags.str() << " ";
      else
        cmd << user_set_subst_flags << " ";
    
      if (!user_set_add_flags.empty())
        cmd << user_set_add_flags << " ";
    
      for (auto &src : src_files)
        cmd << src << " ";
      cmd << "-o " << binary << " ";
    
      if (user_set_subst_libs.empty())
        cmd << libs;
      else
        cmd << user_set_subst_libs;
    
      if (!user_set_add_libs.empty())
        cmd << " " << user_set_add_libs;
    
    #ifdef _WIN32
      cmd << '"';
    #endif
    
      cout << "Compiling " << funcname << " MEX..." << endl << cmd.str() << endl;
    
      if (system(cmd.str().c_str()))
        {
          cerr << "Compilation failed" << endl;
          exit(EXIT_FAILURE);
        }
    }
    
    void
    ModelTree::reorderAuxiliaryEquations()
    {
      using namespace boost;
    
      // Create the mapping between auxiliary variables and auxiliary equations
      int n = static_cast<int>(aux_equations.size());
      map<int, int> auxEndoToEq;
      for (int i = 0; i < n; i++)
        {
          auto varexpr = dynamic_cast<VariableNode *>(aux_equations[i]->arg1);
          assert(varexpr && symbol_table.getType(varexpr->symb_id) == SymbolType::endogenous);
          auxEndoToEq[varexpr->symb_id] = i;
        }
      assert(static_cast<int>(auxEndoToEq.size()) == n);
    
      /* Construct the directed acyclic graph where auxiliary equations are
         vertices and edges represent dependency relationships. */
      using Graph = adjacency_list<vecS, vecS, directedS>;
      Graph g(n);
      for (int i = 0; i < n; i++)
        {
          set<int> endos;
          aux_equations[i]->collectVariables(SymbolType::endogenous, endos);
          for (int endo : endos)
            if (auto it = auxEndoToEq.find(endo);
                it != auxEndoToEq.end() && it->second != i)
              add_edge(i, it->second, g);
        }
    
      // Topological sort of the graph
      using Vertex = graph_traits<Graph>::vertex_descriptor;
      vector<Vertex> ordered;
      topological_sort(g, back_inserter(ordered));
    
      // Reorder auxiliary equations accordingly
      auto aux_equations_old = aux_equations;
      auto index = get(vertex_index, g); // Maps vertex descriptors to their index
      for (int i = 0; i < n; i++)
        aux_equations[i] = aux_equations_old[index[ordered[i]]];
    }
    
    map<tuple<int, int, int>, expr_t>
    ModelTree::collectFirstOrderDerivativesEndogenous()
    {
      map<tuple<int, int, int>, expr_t> endo_derivatives;
      for (auto &[indices, d1] : derivatives[1])
        if (getTypeByDerivID(indices[1]) == SymbolType::endogenous)
          {
            int eq = indices[0];
            int var = symbol_table.getTypeSpecificID(getSymbIDByDerivID(indices[1]));
            int lag = getLagByDerivID(indices[1]);
            endo_derivatives[{ eq, var, lag }] = d1;
          }
      return endo_derivatives;
    }
    
    ModelTree::jacob_map_t
    ModelTree::computeSymbolicJacobian() const
    {
      jacob_map_t symbolic_jacobian;
      for (int i = 0; i < static_cast<int>(equations.size()); i++)
        {
          set<pair<int, int>> endos_and_lags;
          equations[i]->collectEndogenous(endos_and_lags);
          for (const auto &[endo, lag] : endos_and_lags)
            symbolic_jacobian[{ i, endo }] = 1;
        }
      return symbolic_jacobian;
    }
    
    void
    ModelTree::updateReverseVariableEquationOrderings()
    {
      int n = equations.size();
      eq_idx_orig2block.resize(n);
      endo_idx_orig2block.resize(n);
      for (int i = 0; i < n; i++)
        {
          endo_idx_orig2block[endo_idx_block2orig[i]] = i;
          eq_idx_orig2block[eq_idx_block2orig[i]] = i;
        }
    }
    
    expr_t
    ModelTree::getRHSFromLHS(expr_t lhs) const
    {
      for (auto eq : equations)
        if (eq->arg1 == lhs)
          return eq->arg2;
      throw ExprNode::MatchFailureException{"Cannot find an equation with the requested LHS"};
    }