PBGaussModule.h

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/**
 * 
 * Supports optimization.
 * 
 * @file PBGaussModule.h
 * @author YOUR NAME <YOUR EMAIL ADDRESS>
 *
 * @version 2017-05-03
 * Created on 2017-05-03.
 */
 
#pragma once
 
#include <eigen3/Eigen/Core>
#include <eigen3/Eigen/LU>
 
#include <smtrat-solver/Module.h>
#include "PBGaussSettings.h"
 
namespace smtrat
{
    template<typename Settings>
    class PBGaussModule : public Module
    {
    public:
        using MatrixT = Eigen::Matrix<Rational, Eigen::Dynamic, Eigen::Dynamic>;
        using VectorT = Eigen::Matrix<Rational, Eigen::Dynamic, 1>;
        
        private:
            // Members.
            carl::Variables mVariables;
            std::vector<ConstraintT> mEquations;
            std::vector<ConstraintT> mInequalities;
 
            
        public:
            typedef Settings SettingsType;
            std::string moduleName() const {
                return SettingsType::moduleName;
            }
            PBGaussModule(const ModuleInput* _formula, Conditionals& _conditionals, Manager* _manager = nullptr);
 
            ~PBGaussModule();
            
            // Main interfaces.
            /**
             * Informs the module about the given constraint. It should be tried to inform this
             * module about any constraint it could receive eventually before assertSubformula
             * is called (preferably for the first time, but at least before adding a formula
             * containing that constraint).
             * @param _constraint The constraint to inform about.
             * @return false, if it can be easily decided whether the given constraint is inconsistent;
             *        true, otherwise.
             */
            bool informCore( const FormulaT& _constraint );
 
            /**
             * Informs all backends about the so far encountered constraints, which have not yet been communicated.
             * This method must not and will not be called more than once and only before the first runBackends call.
             */
            void init();
 
            /**
             * The module has to take the given sub-formula of the received formula into account.
             *
             * @param _subformula The sub-formula to take additionally into account.
             * @return false, if it can be easily decided that this sub-formula causes a conflict with
             *        the already considered sub-formulas;
             *        true, otherwise.
             */
            bool addCore( ModuleInput::const_iterator _subformula );
 
            /**
             * Removes the subformula of the received formula at the given position to the considered ones of this module.
             * Note that this includes every stored calculation which depended on this subformula, but should keep the other
             * stored calculation, if possible, untouched.
             *
             * @param _subformula The position of the subformula to remove.
             */
            void removeCore( ModuleInput::const_iterator _subformula );
 
            /**
             * Updates the current assignment into the model.
             * Note, that this is a unique but possibly symbolic assignment maybe containing newly introduced variables.
             */
            void updateModel() const;
 
            /**
             * Checks the received formula for consistency.
             * @return True,    if the received formula is satisfiable;
             *       False,   if the received formula is not satisfiable;
             *       Unknown, otherwise.
             */
            Answer checkCore();
            
            /// Convenience wrapper for Eigen::conservativeResizeLike with a zero vector.
            static void conservativeResize(VectorT& v, long newSize) {
                v.conservativeResizeLike(VectorT::Zero(newSize));
            }
            /// Convenience wrapper for Eigen::conservativeResizeLike with a zero matrix.
            static void conservativeResize(MatrixT& m, long newRows, long newCols) {
                m.conservativeResizeLike(MatrixT::Zero(newRows, newCols));
            }
 
            FormulaT gaussAlgorithm();
            FormulaT reconstructEqSystem(const MatrixT& m, const VectorT& b, const carl::Variables& vars, const std::vector<carl::Relation>& rels);
            FormulaT reduce(const MatrixT& u, const VectorT& b, const carl::Variables vars);
            std::vector<Rational> lookForReductionRow(const MatrixT& uMatrix, const VectorT& ineqRow, long column);
 
    };
}