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#pragma once
#include <memory>
#include <array>
#include "Algorithm.hh"
#include "Adjform.hh"
#include "properties/TableauBase.hh"
namespace cadabra {
class meld : public Algorithm
{
public:
meld(const Kernel& kernel, Ex& ex, bool project_as_sum = false);
virtual ~meld();
virtual bool can_apply(iterator it) override;
virtual result_t apply(iterator& it) override;
private:
using tab_t = cadabra::TableauBase::tab_t;
struct ProjectedTerm {
ProjectedTerm(const Kernel& kernel, IndexMap& index_map, Ex& ex, Ex::iterator it);
// Return 'true' if the tensor parts are identical up to index structure
bool compare(const Kernel& kernel, const ProjectedTerm& other);
Ex scalar, tensor;
ProjectedAdjform projection;
Adjform ident;
Ex::iterator it;
bool changed;
};
struct symmetrizer_t {
symmetrizer_t(bool antisymmetric, bool independent) : antisymmetric(antisymmetric), independent(independent) {}
std::vector<size_t> indices;
bool antisymmetric, independent;
};
// Return the tableaux associated with the expression, offsetting
// cells with how many indices *deep* it is
std::vector<tab_t> collect_tableaux(Ex& ex) const;
// Collects all the columns and rows of the tableaux starting at node 'it' and combines
// similar columns where possible. Returns 'true' if the symmetrizers mean the term is
// identically 0
bool collect_symmetries(const std::vector<tab_t>& tabs, std::vector<symmetrizer_t>& symmetrizers) const;
bool collect_symmetries_as_product(const std::vector<tab_t>& tabs, std::vector<symmetrizer_t>& symmetrizers) const;
bool collect_symmetries_as_sum(const std::vector<tab_t>& tabs, std::vector<symmetrizer_t>& symmetrizers) const;
void symmetrize(ProjectedTerm& adj, const std::vector<symmetrizer_t>& symmetries);
void symmetrize_as_product(ProjectedTerm& adj, const std::vector<symmetrizer_t>& symmetrizers);
void symmetrize_as_sum(ProjectedTerm& adj, const std::vector<symmetrizer_t>& symmetries);
void symmetrize_idents(ProjectedTerm& sym);
// Remove non-diagonal terms of diagonal objects
bool can_apply_diagonals(iterator it);
bool apply_diagonals(iterator it);
// Remove terms which contain contractions of traceless objects
bool can_apply_traceless(iterator it);
bool apply_traceless(iterator it);
// Apply the symmetry Tr(ABC) = Tr(BCA) = Tr(CAB)
bool can_apply_cycle_traces(iterator it);
bool apply_cycle_traces(iterator it);
// Compare Young projections of each term for symmetry
bool can_apply_tableaux(iterator it);
bool apply_tableaux(iterator it);
//bool can_apply_side_relations(iterator it);
//bool apply_side_relations(iterator it);
//Ex side_relations;
IndexMap index_map;
bool project_as_sum;
};
}
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