SVE_tpl.h

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/****************************************************************************
 *   This file is part of the aGrUM/pyAgrum library.                        *
 *                                                                          *
 *   Copyright (c) 2005-2026 by                                             *
 *       - Pierre-Henri WUILLEMIN(_at_LIP6)                                 *
 *       - Christophe GONZALES(_at_AMU)                                     *
 *                                                                          *
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 *   SPDX-FileCopyrightText: Copyright 2005-2026                            *
 *       - Pierre-Henri WUILLEMIN(_at_LIP6)                                 *
 *       - Christophe GONZALES(_at_AMU)                                     *
 *   SPDX-License-Identifier: LGPL-3.0-or-later OR MIT                      *
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#pragma once
 

#include <agrum/PRM/classDependencyGraph.h>
#include <agrum/PRM/inference/SVE.h>
 
namespace gum {
  namespace prm {
 
    template < GUM_Numeric GUM_SCALAR >
    std::string __print_attribute__(const PRMInstance< GUM_SCALAR >&  i,
                                    const PRMAttribute< GUM_SCALAR >& a) {
      std::stringstream s;
      const auto&       class_a = i.type().get(a.safeName());
      s << &(a.type().variable()) << " - ";
      s << i.name() << "." << a.safeName() << ": input=" << i.type().isInputNode(class_a);
      s << " output=" << i.type().isOutputNode(class_a)
        << " inner=" << i.type().isInnerNode(class_a);
      return s.str();
    }
 
    template < GUM_Numeric GUM_SCALAR >
    std::string __print_instance__(const PRMInstance< GUM_SCALAR >& i) {
      std::stringstream s;
      s << i.name() << std::endl;
      s << "Attributes: " << std::endl;
      for (auto a: i) {
        s << __print_attribute__(i, *(a.second));
      }
      if (i.type().slotChains().size()) {
        s << std::endl << "SlotChains: " << std::endl;
        for (auto sc: i.type().slotChains()) {
          s << sc->name() << " ";
        }
      }
      return s.str();
    }
 
    template < GUM_Numeric GUM_SCALAR >
    std::string __print_system__(const PRMSystem< GUM_SCALAR >& s) {
      std::stringstream str;
      for (auto i: s) {
        str << __print_instance__(*(i.second)) << std::endl;
      }
      return str.str();
    }
 
    template < typename LIST >
    std::string __print_list__(LIST l) {
      std::stringstream s;
      s << "[";
      for (auto i: l) {
        s << i->name() << " ";
      }
      s << "]";
      return s.str();
    }
 
    template < GUM_Numeric GUM_SCALAR >
    std::string __print_pot__(const Tensor< GUM_SCALAR >& pot) {
      std::stringstream s;
      s << "{";
      for (auto var: pot.variablesSequence()) {
        s << var << ", ";
      }
      s << "}";
      return s.str();
    }
 
    template < typename SET >
    std::string __print_set__(SET set) {
      std::stringstream s;
      s << "[";
      for (auto p: set) {
        s << __print_pot__(*p) << " ";
      }
      s << "]";
      return s.str();
    }
 
    template < GUM_Numeric GUM_SCALAR >
    SVE< GUM_SCALAR >::~SVE() {
      GUM_DESTRUCTOR(SVE);
 
      for (const auto& elt: _elim_orders_)
        delete elt.second;
 
      for (const auto& elt: _lifted_pools_)
        delete elt.second;
 
      if (_class_elim_order_ != nullptr) delete _class_elim_order_;
 
      for (const auto trash: _lifted_trash_)
        delete trash;
 
      for (auto set: _delayedVariables_)
        delete set.second;
    }
 
    template < GUM_Numeric GUM_SCALAR >
    void SVE< GUM_SCALAR >::_eliminateNodes_(const PRMInstance< GUM_SCALAR >* query,
                                             NodeId                           node,
                                             BucketSet&                       pool,
                                             BucketSet&                       trash) {
      Set< const PRMInstance< GUM_SCALAR >* > ignore, eliminated;
      Set< NodeId >                           delayedVars;
      // Downward elimination
      List< const PRMInstance< GUM_SCALAR >* > elim_list;
      ignore.insert(query);
 
      for (auto iter = query->beginInvRef(); iter != query->endInvRef(); ++iter) {
        for (auto child = (*(iter.val())).begin(); child != (*(iter.val())).end(); ++child) {
          if (!ignore.exists(child->first)) {
            _eliminateNodesDownward_(query,
                                     child->first,
                                     pool,
                                     trash,
                                     elim_list,
                                     ignore,
                                     eliminated);
          } else if (!eliminated.exists(child->first)) {
            _addDelayedVariable_(child->first, query, iter.key());
            delayedVars.insert(iter.key());
          }
        }
      }
 
      // Eliminating all nodes in query instance, except query
      InstanceBayesNet< GUM_SCALAR >         bn(*query);
      const auto                             moralg = bn.moralGraph();
      DefaultTriangulation                   t(&moralg, &(bn.modalities()));
      std::vector< const DiscreteVariable* > elim_order;
 
      if (this->hasEvidence(query)) { _insertEvidence_(query, pool); }
 
      for (auto attr = query->begin(); attr != query->end(); ++attr) {
        pool.insert(&(const_cast< Tensor< GUM_SCALAR >& >((*(attr.val())).cpf())));
      }
 
      for (size_t idx = 0; idx < t.eliminationOrder().size(); ++idx) {
        if ((t.eliminationOrder()[idx] != node)
            && (!delayedVars.exists(t.eliminationOrder()[idx]))) {
          auto        var_id = t.eliminationOrder()[idx];
          const auto& var    = bn.variable(var_id);
          elim_order.push_back(&var);
        }
      }
 
      eliminateNodes(elim_order, pool, trash);
 
      // Eliminating delayed variables, if any
      if (_delayedVariables_.exists(query)) { _eliminateDelayedVariables_(query, pool, trash); }
 
      eliminated.insert(query);
      // Eliminating instance in elim_list
      List< const PRMInstance< GUM_SCALAR >* > tmp_list;
 
      while (!elim_list.empty()) {
        if (_checkElimOrder_(query, elim_list.front())) {
          if (!ignore.exists(elim_list.front())) {
            _eliminateNodesDownward_(query,
                                     elim_list.front(),
                                     pool,
                                     trash,
                                     elim_list,
                                     ignore,
                                     eliminated);
          }
        } else {
          tmp_list.insert(elim_list.front());
        }
 
        elim_list.popFront();
      }
 
      // Upward elimination
      for (const auto chain: query->type().slotChains())
        for (const auto parent: query->getInstances(chain->id()))
          if (!ignore.exists(parent))
            _eliminateNodesUpward_(parent, pool, trash, tmp_list, ignore, eliminated);
    }
 
    template < GUM_Numeric GUM_SCALAR >
    void SVE< GUM_SCALAR >::_eliminateDelayedVariables_(const PRMInstance< GUM_SCALAR >* i,
                                                        BucketSet&                       pool,
                                                        BucketSet&                       trash) {
      Set< Tensor< GUM_SCALAR >* > toRemove;
 
      for (const auto var: *_delayedVariables_[i]) {
        MultiDimBucket< GUM_SCALAR >* bucket = new MultiDimBucket< GUM_SCALAR >();
 
        for (const auto pot: pool)
          if (pot->contains(*var)) {
            bucket->add(*pot);
            toRemove.insert(pot);
          }
 
        for (const auto pot: toRemove)
          pool.erase(pot);
 
        for (const auto other: bucket->allVariables())
          if (other != var) bucket->add(*other);
 
        Tensor< GUM_SCALAR >* bucket_pot = new Tensor< GUM_SCALAR >(bucket);
        trash.insert(bucket_pot);
        pool.insert(bucket_pot);
      }
    }
 
    template < GUM_Numeric GUM_SCALAR >
    void SVE< GUM_SCALAR >::_eliminateNodesDownward_(
        const PRMInstance< GUM_SCALAR >*          from,
        const PRMInstance< GUM_SCALAR >*          i,
        BucketSet&                                pool,
        BucketSet&                                trash,
        List< const PRMInstance< GUM_SCALAR >* >& elim_list,
        Set< const PRMInstance< GUM_SCALAR >* >&  ignore,
        Set< const PRMInstance< GUM_SCALAR >* >&  eliminated) {
      Set< NodeId > delayedVars;
      ignore.insert(i);
      // Calling elimination over child instance
      List< const PRMInstance< GUM_SCALAR >* > my_list;
 
      for (auto iter = i->beginInvRef(); iter != i->endInvRef(); ++iter) {
        for (auto child = (*(iter.val())).begin(); child != (*(iter.val())).end(); ++child) {
          if (!ignore.exists(child->first)) {
            _eliminateNodesDownward_(i, child->first, pool, trash, my_list, ignore, eliminated);
          } else if (!eliminated.exists(child->first)) {
            _addDelayedVariable_(child->first, i, iter.key());
            delayedVars.insert(iter.key());
          }
        }
      }
 
      // Eliminating all nodes in current instance
      _variableElimination_(i, pool, trash, (delayedVars.empty() ? 0 : &delayedVars));
      eliminated.insert(i);
 
      // Calling elimination over child's parents
      for (const auto node: my_list) {
        if (_checkElimOrder_(i, node) && (node != from)) {
          if (!ignore.exists(node)) {
            _eliminateNodesDownward_(i, node, pool, trash, elim_list, ignore, eliminated);
          }
        } else if (node != from) {
          elim_list.insert(node);
        }
      }
 
      // Adding parents instance to elim_list
      for (const auto chain: i->type().slotChains()) {
        for (const auto inst: i->getInstances(chain->id())) {
          if (inst != from) { elim_list.insert(inst); }
        }
      }
    }
 
    template < GUM_Numeric GUM_SCALAR >
    void SVE< GUM_SCALAR >::_variableElimination_(const PRMInstance< GUM_SCALAR >* i,
                                                  BucketSet&                       pool,
                                                  BucketSet&                       trash,
                                                  Set< NodeId >*                   delayedVars) {
      if (this->hasEvidence(i)) {
        _eliminateNodesWithEvidence_(i, pool, trash, delayedVars);
      } else {
        _insertLiftedNodes_(i, pool, trash);
 
        for (const auto agg: i->type().aggregates())
          pool.insert(_getAggTensor_(i, agg));
 
        if (auto p_eo = _elim_orders_.tryGet(&(i->type()))) {
          InstanceBayesNet< GUM_SCALAR > bn(*i);
 
          std::vector< const DiscreteVariable* > elim;
 
          for (const auto node: *(*p_eo)) {
            const auto& var = bn.variable(node);
            if (delayedVars != nullptr) {
              if (!delayedVars->exists(node)) {
                const auto& var = bn.variable(node);
                elim.push_back(&var);
              }
            } else {
              elim.push_back(&var);
            }
          }
 
          eliminateNodes(elim, pool, trash);
        }
      }
 
      // Eliminating delayed variables, if any
      if (_delayedVariables_.exists(i)) { _eliminateDelayedVariables_(i, pool, trash); }
    }
 
    template < GUM_Numeric GUM_SCALAR >
    void SVE< GUM_SCALAR >::_eliminateNodesUpward_(
        const PRMInstance< GUM_SCALAR >*          i,
        BucketSet&                                pool,
        BucketSet&                                trash,
        List< const PRMInstance< GUM_SCALAR >* >& elim_list,
        Set< const PRMInstance< GUM_SCALAR >* >&  ignore,
        Set< const PRMInstance< GUM_SCALAR >* >&  eliminated) {
      // Downward elimination
      ignore.insert(i);
 
      for (auto iter = i->beginInvRef(); iter != i->endInvRef(); ++iter) {
        for (auto child = (*(iter.val())).begin(); child != (*(iter.val())).end(); ++child) {
          if (!ignore.exists(child->first)) {
            _eliminateNodesDownward_(i, child->first, pool, trash, elim_list, ignore, eliminated);
          }
        }
      }
 
      // Eliminating all nodes in i instance
      _variableElimination_(i, pool, trash);
      eliminated.insert(i);
      // Eliminating instance in elim_list
      List< const PRMInstance< GUM_SCALAR >* > tmp_list;
 
      while (!elim_list.empty()) {
        if (_checkElimOrder_(i, elim_list.front())) {
          if (!ignore.exists(elim_list.front())) {
            _eliminateNodesDownward_(i,
                                     elim_list.front(),
                                     pool,
                                     trash,
                                     elim_list,
                                     ignore,
                                     eliminated);
          }
        } else {
          tmp_list.insert(elim_list.front());
        }
 
        elim_list.popFront();
      }
 
      // Upward elimination
      for (const auto chain: i->type().slotChains()) {
        for (const auto parent: i->getInstances(chain->id())) {
          if (!ignore.exists(parent)) {
            _eliminateNodesUpward_(parent, pool, trash, tmp_list, ignore, eliminated);
          }
        }
      }
    }
 
    template < GUM_Numeric GUM_SCALAR >
    void SVE< GUM_SCALAR >::_eliminateNodesWithEvidence_(const PRMInstance< GUM_SCALAR >* i,
                                                         BucketSet&                       pool,
                                                         BucketSet&                       trash,
                                                         Set< NodeId >* delayedVars) {
      // First we check if evidences are on inner nodes
      bool inner = false;
 
      for (const auto& elt: this->evidence(i)) {
        inner
            = i->type().isInputNode(i->get(elt.first)) || i->type().isInnerNode(i->get(elt.first));
 
        if (inner) { break; }
      }
 
      // Evidence on inner nodes
      if (inner) {
        BucketSet tmp_pool;
        _insertEvidence_(i, tmp_pool);
 
        // We need a local to not eliminate queried inner nodes of the same
        // class
        for (const auto& elt: *i) {
          tmp_pool.insert(&(const_cast< Tensor< GUM_SCALAR >& >(elt.second->cpf())));
        }
 
        InstanceBayesNet< GUM_SCALAR > bn(*i);
        const auto                     moralg = bn.moralGraph();
        DefaultTriangulation           t(&moralg, &(bn.modalities()));
        const std::vector< NodeId >&   full_elim_order = t.eliminationOrder();
        // Removing Output nodes of elimination order
        std::vector< const DiscreteVariable* > inner_elim_order;
        std::vector< const DiscreteVariable* > output_elim_order;
 
        for (size_t idx = 0; idx < full_elim_order.size(); ++idx) {
          auto        var_id = full_elim_order[idx];
          const auto& var    = bn.variable(var_id);
 
          if (!i->type().isOutputNode(i->get(full_elim_order[idx]))) {
            inner_elim_order.push_back(&var);
          } else if (delayedVars != nullptr) {
            if (!delayedVars->exists(full_elim_order[idx])) { output_elim_order.push_back(&var); }
          } else {
            output_elim_order.push_back(&var);
          }
        }
 
        eliminateNodes(inner_elim_order, tmp_pool, trash);
 
        // Now we add the new tensors in pool and eliminate output nodes
        for (const auto pot: tmp_pool)
          pool.insert(pot);
 
        if (!output_elim_order.empty()) eliminateNodes(output_elim_order, pool, trash);
 
      } else {
        InstanceBayesNet< GUM_SCALAR > bn(*i);
        _insertEvidence_(i, pool);
        _insertLiftedNodes_(i, pool, trash);
 
        for (const auto agg: i->type().aggregates())
          pool.insert(_getAggTensor_(i, agg));
 
        if (auto p_eo2 = _elim_orders_.tryGet(&(i->type())); !p_eo2) {
          GUM_ERROR(FatalError, "there should be at least one node here.")
        } else {
          std::vector< const DiscreteVariable* > elim;
 
          for (auto iter = (*p_eo2)->begin(); iter != (*p_eo2)->end(); ++iter) {
            const auto& var = bn.variable(*iter);
            if (delayedVars != nullptr) {
              if (!delayedVars->exists(*iter)) { elim.push_back(&var); }
            } else {
              elim.push_back(&var);
            }
          }
 
          eliminateNodes(elim, pool, trash);
        }
      }
    }
 
    template < GUM_Numeric GUM_SCALAR >
    void SVE< GUM_SCALAR >::_insertLiftedNodes_(const PRMInstance< GUM_SCALAR >* i,
                                                BucketSet&                       pool,
                                                BucketSet&                       trash) {
      SVE< GUM_SCALAR >::BucketSet* lifted_pool = 0;
 
      auto p_lp = _lifted_pools_.tryGet(&(i->type()));
      if (!p_lp) {
        _initLiftedNodes_(i->type());
        p_lp = _lifted_pools_.tryGet(&(i->type()));
      }
      lifted_pool = *p_lp;
 
      for (const auto lifted_pot: *lifted_pool) {
        Tensor< GUM_SCALAR >* pot = copyTensor(i->bijection(), *lifted_pot);
        pool.insert(pot);
        trash.insert(pot);
      }
    }
 
    template < GUM_Numeric GUM_SCALAR >
    void SVE< GUM_SCALAR >::_initLiftedNodes_(const PRMClass< GUM_SCALAR >& c) {
      BucketSet* lifted_pool = new BucketSet();
      _lifted_pools_.insert(&c, lifted_pool);
      NodeSet inners, outers;
 
      for (const auto node: c.containerDag().nodes())
        if (PRMClassElement< GUM_SCALAR >::isAttribute(c.get(node))) {
          if (c.isOutputNode(c.get(node))) outers.insert(node);
          else if (!outers.exists(node)) inners.insert(node);
 
          lifted_pool->insert(const_cast< Tensor< GUM_SCALAR >* >(&(c.get(node).cpf())));
        } else if (PRMClassElement< GUM_SCALAR >::isAggregate(c.get(node))) {
          outers.insert(node);
 
          // We need to put in the output_elim_order aggregator's parents which
          // are
          // innner nodes
          for (const auto par: c.containerDag().parents(node))
            if (PRMClassElement< GUM_SCALAR >::isAttribute(c.get(par))
                && c.isInnerNode(c.get(par))) {
              inners.erase(par);
              outers.insert(par);
            }
        }
 
      // Now we proceed with the elimination of inner attributes
      ClassBayesNet< GUM_SCALAR > bn(c);
      List< NodeSet >             partial_ordering;
 
      if (inners.size()) partial_ordering.push_back(inners);
 
      if (outers.size()) partial_ordering.push_back(outers);
 
      const auto                  moralg = bn.moralGraph();
      PartialOrderedTriangulation t(&moralg, &(bn.modalities()), &partial_ordering);
 
      for (size_t idx = 0; idx < inners.size(); ++idx)
        eliminateNode(&(c.get(t.eliminationOrder()[idx]).type().variable()),
                      *lifted_pool,
                      _lifted_trash_);
 
      // If there is not only inner and input Attributes
      if (outers.size()) {
        _elim_orders_.insert(&c,
                             new std::vector< NodeId >(t.eliminationOrder().begin() + inners.size(),
                                                       t.eliminationOrder().end()));
      }
    }
 
    template < GUM_Numeric GUM_SCALAR >
    void SVE< GUM_SCALAR >::_initElimOrder_() {
      ClassDependencyGraph< GUM_SCALAR >                        cdg(*(this->prm_));
      Sequence< const PRMClassElementContainer< GUM_SCALAR >* > class_elim_order;
      std::list< NodeId >                                       l;
 
      for (const auto node: cdg.internalDag().nodes()) {
        if (cdg.internalDag().parents(node).empty()) { l.push_back(node); }
      }
 
      Set< NodeId > visited_node;
 
      while (!l.empty()) {
        visited_node.insert(l.front());
 
        if (!class_elim_order.exists(cdg.get(l.front()).first)) {
          class_elim_order.insert(cdg.get(l.front()).first);
        }
 
        for (const auto child: cdg.internalDag().children(l.front())) {
          if (!visited_node.contains(child)) { l.push_back(child); }
        }
 
        l.pop_front();
      }
 
      _class_elim_order_ = new Sequence< std::string >();
      for (auto c: class_elim_order) {
        std::string name = c->name();
        if (auto pos = name.find_first_of("<"); pos != std::string::npos) {
          name = name.substr(0, pos);
        }
        try {
          _class_elim_order_->insert(name);
        } catch (DuplicateElement const&) {}
      }
    }
 
    template < GUM_Numeric GUM_SCALAR >
    void SVE< GUM_SCALAR >::posterior_(const Chain& chain, Tensor< GUM_SCALAR >& m) {
      const PRMInstance< GUM_SCALAR >*  i   = chain.first;
      const PRMAttribute< GUM_SCALAR >* elt = chain.second;
      SVE< GUM_SCALAR >::BucketSet      pool, trash;
 
      _eliminateNodes_(i, elt->id(), pool, trash);
 
      std::vector< Tensor< GUM_SCALAR >* > result;
 
      for (const auto pot: pool) {
        if (pot->contains(elt->type().variable())) { result.push_back(pot); }
      }
 
      while (result.size() > 1) {
        auto& p1 = *(result.back());
        result.pop_back();
        auto& p2 = *(result.back());
        result.pop_back();
        auto mult = new Tensor< GUM_SCALAR >(p1 * p2);
        trash.insert(mult);
        result.push_back(mult);
      }
 
      m = *(result.back());
      m.normalize();
 
      for (const auto pot: trash) {
        delete pot;
      }
    }
 
    template < GUM_Numeric GUM_SCALAR >
    void SVE< GUM_SCALAR >::joint_(const std::vector< Chain >& queries, Tensor< GUM_SCALAR >& j) {
      GUM_ERROR(FatalError, "Not implemented.")
    }
 
    template < GUM_Numeric GUM_SCALAR >
    SVE< GUM_SCALAR >::SVE(const PRM< GUM_SCALAR >& prm, const PRMSystem< GUM_SCALAR >& system) :
        PRMInference< GUM_SCALAR >(prm, system), _class_elim_order_(0) {
      GUM_CONSTRUCTOR(SVE);
    }
 
    template < GUM_Numeric GUM_SCALAR >
    void SVE< GUM_SCALAR >::_insertEvidence_(const PRMInstance< GUM_SCALAR >* i, BucketSet& pool) {
      for (const auto& elt: this->evidence(i))
        pool.insert(const_cast< Tensor< GUM_SCALAR >* >(elt.second));
    }
 
    template < GUM_Numeric GUM_SCALAR >
    std::vector< NodeId >& SVE< GUM_SCALAR >::_getElimOrder_(const PRMClass< GUM_SCALAR >& c) {
      return *(_elim_orders_[&c]);
    }
 
    template < GUM_Numeric GUM_SCALAR >
    std::string SVE< GUM_SCALAR >::_trim_(std::string_view s) {
      if (auto pos = s.find_first_of("<"); pos != std::string::npos) {
        return std::string{s.substr(0, pos)};
      }
      return std::string{s};
    }
 
    template < GUM_Numeric GUM_SCALAR >
    bool SVE< GUM_SCALAR >::_checkElimOrder_(const PRMInstance< GUM_SCALAR >* first,
                                             const PRMInstance< GUM_SCALAR >* second) {
      if (_class_elim_order_ == 0) { _initElimOrder_(); }
 
      auto first_name  = _trim_(first->type().name());
      auto second_name = _trim_(second->type().name());
      return (_class_elim_order_->pos(first_name) <= _class_elim_order_->pos(second_name));
    }
 
    template < GUM_Numeric GUM_SCALAR >
    Tensor< GUM_SCALAR >* SVE< GUM_SCALAR >::_getAggTensor_(const PRMInstance< GUM_SCALAR >*  i,
                                                            const PRMAggregate< GUM_SCALAR >* agg) {
      return &(const_cast< Tensor< GUM_SCALAR >& >(i->get(agg->id()).cpf()));
    }
 
    template < GUM_Numeric GUM_SCALAR >
    void SVE< GUM_SCALAR >::evidenceAdded_(const Chain& chain) {
      // Do nothing
    }
 
    template < GUM_Numeric GUM_SCALAR >
    void SVE< GUM_SCALAR >::evidenceRemoved_(const Chain& chain) {
      // Do nothing
    }
 
    template < GUM_Numeric GUM_SCALAR >
    void SVE< GUM_SCALAR >::_addDelayedVariable_(const PRMInstance< GUM_SCALAR >* i,
                                                 const PRMInstance< GUM_SCALAR >* j,
                                                 NodeId                           id) {
      auto p_dv = _delayedVariables_.tryGet(i);
      if (!p_dv) {
        _delayedVariables_.insert(i, new gum::VariableSet());
        p_dv = _delayedVariables_.tryGet(i);
      }
      try {
        (*p_dv)->insert(&(j->get(id).type().variable()));
      } catch (DuplicateElement const&) {
        // happends if j->get(id) is parent of more than one variable in i
      }
 
      static std::string dot = ".";
 
      auto key = j->name() + dot + j->get(id).safeName();
      if (auto p_cnt = _delayedVariablesCounters_.tryGet(key)) {
        *p_cnt += 1;
      } else {
        _delayedVariablesCounters_.insert(key, 1);
      }
    }
 
    template < GUM_Numeric GUM_SCALAR >
    std::string SVE< GUM_SCALAR >::name() const {
      return "SVE";
    }
 
  } /* namespace prm */
} /* namespace gum */