diff --git a/src/backends/maxima/maximasession.cpp b/src/backends/maxima/maximasession.cpp
index aaa37601..7bfbb00a 100644
--- a/src/backends/maxima/maximasession.cpp
+++ b/src/backends/maxima/maximasession.cpp
@@ -1,342 +1,343 @@
 /*
     This program 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 2
     of the License, or (at your option) any later version.
 
     This program 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 this program; if not, write to the Free Software
     Foundation, Inc., 51 Franklin Street, Fifth Floor,
     Boston, MA  02110-1301, USA.
 
     ---
     Copyright (C) 2009-2012 Alexander Rieder <alexanderrieder@gmail.com>
     Copyright (C) 2017-2018 Alexander Semke (alexander.semke@web.de)
  */
 
 #include "maximasession.h"
 #include "maximaexpression.h"
 #include "maximacompletionobject.h"
 #include "maximasyntaxhelpobject.h"
 #include "maximahighlighter.h"
 #include "maximavariablemodel.h"
 #include "result.h"
 #include "settings.h"
 
 #include <QDebug>
 #include <QProcess>
 #include <QTimer>
 
 #include <KMessageBox>
 #include <KLocalizedString>
 
 #ifndef Q_OS_WIN
 #include <signal.h>
 #endif
 
 
 //NOTE: the \\s in the expressions is needed, because Maxima seems to sometimes insert newlines/spaces between the letters
 //maybe this is caused by some behaviour if the Prompt is split into multiple "readStdout" calls
 //the Expressions are encapsulated in () to allow capturing for the text
 const QRegExp MaximaSession::MaximaOutputPrompt=QRegExp(QLatin1String("(\\(\\s*%\\s*o\\s*[0-9\\s]*\\))")); //Text, maxima outputs, before any output
 const QRegExp MaximaSession::MaximaInputPrompt = QRegExp(QLatin1String("(\\(\\s*%\\s*i\\s*[0-9\\s]*\\))"));
 
 
 MaximaSession::MaximaSession( Cantor::Backend* backend ) : Session(backend),
     m_process(nullptr),
     m_variableModel(new MaximaVariableModel(this)),
     m_justRestarted(false)
 {
 }
 
 void MaximaSession::login()
 {
     qDebug()<<"login";
 
     if (m_process)
         return; //TODO: why do we call login() again?!?
 
     emit loginStarted();
     QStringList arguments;
     arguments << QLatin1String("--quiet"); //Suppress Maxima start-up message
     const QString initFile = QStandardPaths::locate(QStandardPaths::GenericDataLocation, QLatin1String("cantor/maximabackend/cantor-initmaxima.lisp"));
     arguments << QLatin1String("--init-lisp=") + initFile; //Set the name of the Lisp initialization file
 
     m_process = new QProcess(this);
     m_process->start(MaximaSettings::self()->path().toLocalFile(), arguments);
     m_process->waitForStarted();
     m_process->waitForReadyRead();
     qDebug()<<m_process->readAllStandardOutput();
 
     connect(m_process, SIGNAL(finished(int,QProcess::ExitStatus)), this, SLOT(restartMaxima()));
     connect(m_process, SIGNAL(readyReadStandardOutput()), this, SLOT(readStdOut()));
     connect(m_process, SIGNAL(readyReadStandardError()), this, SLOT(readStdErr()));
     connect(m_process, SIGNAL(error(QProcess::ProcessError)), this, SLOT(reportProcessError(QProcess::ProcessError)));
 
     if(!MaximaSettings::self()->autorunScripts().isEmpty()){
         QString autorunScripts = MaximaSettings::self()->autorunScripts().join(QLatin1String(";"));
         autorunScripts.append(QLatin1String(";kill(labels)")); // Reset labels after running autorun scripts
         evaluateExpression(autorunScripts, MaximaExpression::DeleteOnFinish, true);
     }
 
     changeStatus(Session::Done);
     emit loginDone();
     qDebug()<<"login done";
 }
 
 void MaximaSession::logout()
 {
     qDebug()<<"logout";
 
     if(!m_process)
         return;
 
     disconnect(m_process, nullptr, this, nullptr);
 
 //     if(status()==Cantor::Session::Running)
         //TODO: terminate the running expressions first
 
     write(QLatin1String("quit();\n"));
     qDebug()<<"waiting for maxima to finish";
     m_process->waitForFinished();
     qDebug()<<"maxima exit finished";
 
     if(m_process->state() != QProcess::NotRunning)
     {
         m_process->kill();
         qDebug()<<"maxima still running, process kill enforced";
     }
 
     expressionQueue().clear();
     delete m_process;
     m_process = nullptr;
+    m_variableModel->clear();
 
     changeStatus(Status::Disable);
 
     qDebug()<<"logout done";
 }
 
 Cantor::Expression* MaximaSession::evaluateExpression(const QString& cmd, Cantor::Expression::FinishingBehavior behave, bool internal)
 {
     qDebug() << "evaluating: " << cmd;
     MaximaExpression* expr = new MaximaExpression(this, internal);
     expr->setFinishingBehavior(behave);
     expr->setCommand(cmd);
     expr->evaluate();
 
     return expr;
 }
 
 void MaximaSession::readStdErr()
 {
    qDebug()<<"reading stdErr";
    if (!m_process)
        return;
    QString out=QLatin1String(m_process->readAllStandardError());
 
    if(expressionQueue().size()>0)
    {
        MaximaExpression* expr = static_cast<MaximaExpression*>(expressionQueue().first());
        expr->parseError(out);
    }
 }
 
 void MaximaSession::readStdOut()
 {
     QString out = QLatin1String(m_process->readAllStandardOutput());
     m_cache += out;
 
     //collect the multi-line output until Maxima has finished the calculation and returns a new promt
     if ( !out.contains(QLatin1String("</cantor-prompt>")) )
         return;
 
     if(expressionQueue().isEmpty())
     {
         //queue is empty, interrupt was called, nothing to do here
         qDebug()<<m_cache;
         m_cache.clear();
         return;
     }
 
     MaximaExpression* expr = static_cast<MaximaExpression*>(expressionQueue().first());
     if (!expr)
         return; //should never happen
 
     qDebug()<<"output: " << m_cache;
     expr->parseOutput(m_cache);
     m_cache.clear();
 }
 
 void MaximaSession::reportProcessError(QProcess::ProcessError e)
 {
     qDebug()<<"process error"<<e;
     if(e==QProcess::FailedToStart)
     {
         changeStatus(Cantor::Session::Done);
         emit error(i18n("Failed to start Maxima"));
     }
 }
 
 void MaximaSession::currentExpressionChangedStatus(Cantor::Expression::Status status)
 {
     Cantor::Expression* expression = expressionQueue().first();
     qDebug() << "expression status changed: command = " << expression->command() << ", status = " << status;
 
     if(status!=Cantor::Expression::Computing) //The session is ready for the next command
     {
         qDebug()<<"################################## EXPRESSION END ###############################################";
         disconnect(expression, SIGNAL(statusChanged(Cantor::Expression::Status)),
                    this, SLOT(currentExpressionChangedStatus(Cantor::Expression::Status)));
 
         expressionQueue().removeFirst();
         if(expressionQueue().isEmpty())
         {
             //if we are done with all the commands in the queue,
             //use the opportunity to update the variablemodel (if the last command wasn't already an update, as infinite loops aren't fun)
             QRegExp exp=QRegExp(QRegExp::escape(MaximaVariableModel::inspectCommand).arg(QLatin1String("(values|functions)")));
             QRegExp exp2=QRegExp(QRegExp::escape(MaximaVariableModel::variableInspectCommand).arg(QLatin1String("(values|functions)")));
 
             if(MaximaSettings::variableManagement()&&!exp.exactMatch(expression->command())&&!exp2.exactMatch(expression->command()))
             {
                 m_variableModel->checkForNewFunctions();
                 m_variableModel->checkForNewVariables();
             }else
             {
                 changeStatus(Cantor::Session::Done);
             }
 
         }else
         {
             runFirstExpression();
         }
     }
 }
 
 void MaximaSession::runFirstExpression()
 {
     qDebug()<<"running next expression";
     if (!m_process)
         return;
 
     if(!expressionQueue().isEmpty())
     {
         MaximaExpression* expr = static_cast<MaximaExpression*>(expressionQueue().first());
         QString command=expr->internalCommand();
         connect(expr, SIGNAL(statusChanged(Cantor::Expression::Status)), this, SLOT(currentExpressionChangedStatus(Cantor::Expression::Status)));
 
         expr->setStatus(Cantor::Expression::Computing);
         if(command.isEmpty())
         {
             qDebug()<<"empty command";
             expr->forceDone();
         }
         else
         {
             m_cache.clear();
             write(command + QLatin1Char('\n'));
         }
     }
 }
 
 void MaximaSession::interrupt()
 {
     if(!expressionQueue().isEmpty())
     {
         qDebug()<<"interrupting " << expressionQueue().first()->command();
         if(m_process->state() != QProcess::NotRunning)
         {
 #ifndef Q_OS_WIN
             const int pid=m_process->pid();
             kill(pid, SIGINT);
 #else
             ; //TODO: interrupt the process on windows
 #endif
         }
         expressionQueue().first()->interrupt();
         expressionQueue().removeFirst();
         foreach (Cantor::Expression* expression, expressionQueue())
             expression->setStatus(Cantor::Expression::Done);
         expressionQueue().clear();
 
         qDebug()<<"done interrupting";
     }
 
     changeStatus(Cantor::Session::Done);
     m_cache.clear();
 }
 
 void MaximaSession::sendInputToProcess(const QString& input)
 {
     write(input);
 }
 
 void MaximaSession::restartMaxima()
 {
     qDebug()<<"restarting maxima cooldown: "<<m_justRestarted;
 
     if(!m_justRestarted)
     {
         emit error(i18n("Maxima crashed. restarting..."));
         //remove the command that caused maxima to crash (to avoid infinite loops)
         if(!expressionQueue().isEmpty())
             expressionQueue().removeFirst();
 
         m_justRestarted=true;
         QTimer::singleShot(1000, this, SLOT(restartsCooledDown()));
 
         disconnect(m_process, SIGNAL(finished(int,QProcess::ExitStatus)), this, SLOT(restartMaxima()));
         login();
     }else
     {
         if(!expressionQueue().isEmpty())
             expressionQueue().removeFirst();
         KMessageBox::error(nullptr, i18n("Maxima crashed twice within a short time. Stopping to try starting"), i18n("Error - Cantor"));
     }
 }
 
 void MaximaSession::restartsCooledDown()
 {
     qDebug()<<"maxima restart cooldown";
     m_justRestarted=false;
 }
 
 void MaximaSession::setTypesettingEnabled(bool enable)
 {
     //we use the lisp command to set the variable, as those commands
     //don't mess with the labels and history
     const QString& val=QLatin1String((enable==true ? "t":"nil"));
     evaluateExpression(QString::fromLatin1(":lisp(setf $display2d %1)").arg(val), Cantor::Expression::DeleteOnFinish, true);
 
     Cantor::Session::setTypesettingEnabled(enable);
 }
 
 Cantor::CompletionObject* MaximaSession::completionFor(const QString& command, int index)
 {
     return new MaximaCompletionObject(command, index, this);
 }
 
 Cantor::SyntaxHelpObject* MaximaSession::syntaxHelpFor(const QString& command)
 {
     return new MaximaSyntaxHelpObject(command, this);
 }
 
 QSyntaxHighlighter* MaximaSession::syntaxHighlighter(QObject* parent)
 {
     return new MaximaHighlighter(parent, this);
 }
 
 QAbstractItemModel* MaximaSession::variableModel()
 {
     return m_variableModel;
 }
 
 void MaximaSession::write(const QString& exp) {
     qDebug()<<"################################## EXPRESSION START ###############################################";
     qDebug()<<"sending expression to maxima process: " << exp;
     m_process->write(exp.toUtf8());
 }
diff --git a/src/backends/maxima/maximavariablemodel.cpp b/src/backends/maxima/maximavariablemodel.cpp
index 580821d1..3dae7a15 100644
--- a/src/backends/maxima/maximavariablemodel.cpp
+++ b/src/backends/maxima/maximavariablemodel.cpp
@@ -1,269 +1,278 @@
 /*
     This program 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 2
     of the License, or (at your option) any later version.
 
     This program 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 this program; if not, write to the Free Software
     Foundation, Inc., 51 Franklin Street, Fifth Floor,
     Boston, MA  02110-1301, USA.
 
     ---
     Copyright (C) 2012 Alexander Rieder <alexanderrieder@gmail.com>
  */
 
 #include "maximavariablemodel.h"
 
 #include "maximasession.h"
 #include "maximaexpression.h"
 #include "textresult.h"
 #include "latexresult.h"
 
 #include <QDebug>
 #include <KLocalizedString>
 
 //command used to inspect a maxima variable. %1 is the name of that variable
 const QString MaximaVariableModel::inspectCommand=QLatin1String(":lisp($disp $%1)");
 const QString MaximaVariableModel::variableInspectCommand=QLatin1String(":lisp(cantor-inspect $%1)");
 
 MaximaVariableModel::MaximaVariableModel( MaximaSession* session) : Cantor::DefaultVariableModel(session)
 {
 
 }
 
+void MaximaVariableModel::clear()
+{
+    emit functionsRemoved(functionNames());
+    emit variablesRemoved(variableNames());
+    m_functions.clear();
+    m_variables.clear();
+    DefaultVariableModel::clearVariables();
+}
+
 void MaximaVariableModel::checkForNewVariables()
 {
     qDebug()<<"checking for new variables";
     const QString& cmd=variableInspectCommand.arg(QLatin1String("values"));
     Cantor::Expression* expr=session()->evaluateExpression(cmd, Cantor::Expression::FinishingBehavior::DoNotDelete, true);
     connect(expr, &Cantor::Expression::statusChanged, this, &MaximaVariableModel::parseNewVariables);
 }
 
 void MaximaVariableModel::checkForNewFunctions()
 {
     qDebug()<<"checking for new functions";
     const QString& cmd=inspectCommand.arg(QLatin1String("functions"));
     Cantor::Expression* expr=session()->evaluateExpression(cmd, Cantor::Expression::FinishingBehavior::DoNotDelete, true);
 
     connect(expr, &Cantor::Expression::statusChanged, this, &MaximaVariableModel::parseNewFunctions);
 }
 
 QList<Cantor::DefaultVariableModel::Variable> parse(MaximaExpression* expr)
 {
     if(!expr || expr->status()!=Cantor::Expression::Done || expr->results().isEmpty()) {
         return QList<Cantor::DefaultVariableModel::Variable>();
     }
 
     //for parsing of names and values below (old code) we need to combine multiple results back to one string
     QString text;
     for (auto* result : expr->results())
     {
         if(result->type()==Cantor::TextResult::Type)
             text += dynamic_cast<Cantor::TextResult*>(result)->plain();
         else if(expr->result()->type()==Cantor::LatexResult::Type)
             text += dynamic_cast<Cantor::LatexResult*>(result)->plain();
     }
 
     const int nameIndex=text.indexOf(QLatin1Char(']'));
     QString namesString=text.left(nameIndex);
     //namesString.chop(1);
     namesString=namesString.mid(1);
     namesString=namesString.trimmed();
 
     qDebug()<<"variable names: "<<namesString;
     if(namesString.isEmpty())
         return QList<Cantor::DefaultVariableModel::Variable>();
 
     QStringList variableNames;
     QString valuesString;
     bool hasValues = false;
     QStringList variableValues;
     if ( namesString.contains(QLatin1Char(')')) )
     {
         //function definition(s): e.g
         //text = "[f1(x),f2(x,y),f3(x,y,z)]\n$DONE"
         //nameString = f1(x),f2(x,y),f3(x,y,z)
         //variableString = "\n$DONE"
         variableNames = namesString.split(QLatin1String("),"));
     }
     else
     {
         //variable definition(s): e.g.
         //text = "[a,b]\n1\n\"-cantor-value-separator-\"\n2\n\"-cantor-value-separator-\"\n($A $B)"
         //nameString = "[a,b]"
         //variableString = "\n1\n\"-cantor-value-separator-\"\n2\n\"-cantor-value-separator-\"\n($A $B)"
         variableNames = namesString.split(QLatin1Char(','));
         valuesString = text.mid(nameIndex+1).trimmed();
         valuesString = valuesString.remove(QLatin1String("\n")); //lists with many elements have line breaks, remove them
         variableValues = valuesString.split(QLatin1String("\"-cantor-value-separator-\""));
         hasValues = variableValues.isEmpty();
     }
 
     qDebug()<<variableNames;
     qDebug()<<"string: "<<valuesString;
     qDebug()<<"values: "<<variableValues;
     qDebug()<<"has Values: "<<hasValues;
 
     QList<Cantor::DefaultVariableModel::Variable> variables;
     variables.reserve(variableNames.size());
     for(int i=0;i<variableNames.size();i++)
     {
         Cantor::DefaultVariableModel::Variable var;
         var.name=variableNames.at(i);;
         if(variableValues.size()>i)
         {
             var.value=variableValues.at(i).trimmed();
             var.value=var.value.remove(QLatin1String("\n")); //lists with many elements have line breaks, remove them
         }
         else
             var.value=QLatin1String("unknown");
 
         variables<<var;
     }
 
     return variables;
 }
 
 void MaximaVariableModel::parseNewVariables(Cantor::Expression::Status status)
 {
     if (status != Cantor::Expression::Done && status != Cantor::Expression::Error)
         return;
 
     qDebug()<<"parsing variables";
     MaximaExpression* expr=dynamic_cast<MaximaExpression*>(sender());
 
     QList<Variable> newVars=parse(expr);
     QStringList addedVars;
     QStringList removedVars;
     //remove the old variables
     for (const Variable& var : m_variables)
     {
         //check if this var is present in the new variables
         bool found=false;
         for (const Variable& var2 : newVars)
         {
             if(var.name==var2.name)
             {
                 found=true;
                 break;
             }
         }
 
         if(!found)
         {
             removeVariable(var);
             removedVars<<var.name;
         }
     }
 
     for (const Variable& var : newVars)
     {
         addVariable(var);
 
         addedVars<<var.name;
     }
 
     m_variables=newVars;
 
     //the expression is not needed anymore
     expr->deleteLater();
 
     emit variablesAdded(addedVars);
     emit variablesRemoved(removedVars);
 }
 
 void MaximaVariableModel::parseNewFunctions(Cantor::Expression::Status status)
 {
     if (status != Cantor::Expression::Done && status != Cantor::Expression::Error)
         return;
 
     qDebug()<<"parsing functions";
     MaximaExpression* expr=dynamic_cast<MaximaExpression*>(sender());
 
     QList<Variable> newVars=parse(expr);
     QStringList addedVars;
     QStringList removedVars;
 
     //remove the old variables
     for (const Variable& var : m_functions)
     {
         //check if this var is present in the new variables
         bool found=false;
         for (const Variable& var2 : newVars)
         {
             if(var.name==var2.name)
             {
                 found=true;
                 break;
             }
         }
 
         if(!found)
         {
             removeVariable(var);
             removedVars<<var.name;
         }
     }
 
     for (Variable var : newVars)
     {
         var.value=i18n("function");
         addVariable(var);
         //todo: check if the variable is actually new?
         addedVars<<var.name;
     }
 
     m_functions=newVars;
 
     //the expression is not needed anymore
     expr->deleteLater();
 
     emit functionsAdded(addedVars);
     emit functionsRemoved(removedVars);
 }
 
 MaximaSession* MaximaVariableModel::maximaSession()
 {
     return static_cast<MaximaSession*> (session());
 }
 
 QList<Cantor::DefaultVariableModel::Variable> MaximaVariableModel::variables()
 {
     return m_variables;
 }
 
 QList<Cantor::DefaultVariableModel::Variable> MaximaVariableModel::functions()
 {
     return m_functions;
 }
 
 QStringList MaximaVariableModel::variableNames()
 {
     QStringList names;
     for (const Cantor::DefaultVariableModel::Variable& var : m_variables)
         names<<var.name;
 
     return names;
 }
 
 QStringList MaximaVariableModel::functionNames(bool stripParameters)
 {
     QStringList names;
     for (const Cantor::DefaultVariableModel::Variable& var : m_functions)
     {
         QString name=var.name;
         if(stripParameters)
         {
             name=name.left(name.lastIndexOf(QLatin1Char('(')));
         }
         names<<name;
     }
 
     return names;
 }
diff --git a/src/backends/maxima/maximavariablemodel.h b/src/backends/maxima/maximavariablemodel.h
index 9e7c147b..c660da17 100644
--- a/src/backends/maxima/maximavariablemodel.h
+++ b/src/backends/maxima/maximavariablemodel.h
@@ -1,69 +1,71 @@
 /*
     This program 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 2
     of the License, or (at your option) any later version.
 
     This program 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 this program; if not, write to the Free Software
     Foundation, Inc., 51 Franklin Street, Fifth Floor,
     Boston, MA  02110-1301, USA.
 
     ---
     Copyright (C) 2012 Alexander Rieder <alexanderrieder@gmail.com>
  */
 
 #ifndef _MAXIMAVARIABLEMODEL_H
 #define _MAXIMAVARIABLEMODEL_H
 
 #include "defaultvariablemodel.h"
 #include <QStringList>
 
 class MaximaSession;
 
 class MaximaVariableModel : public Cantor::DefaultVariableModel
 {
   Q_OBJECT
   public:
     static const QString inspectCommand;
     static const QString variableInspectCommand;
 
     explicit MaximaVariableModel( MaximaSession* session);
     ~MaximaVariableModel() override = default;
 
+    void clear();
+
     QList<Variable> variables();
     QList<Variable> functions();
 
     QStringList variableNames();
     QStringList functionNames(bool stripParameters=false);
 
   public Q_SLOTS:
       void checkForNewVariables();
       void checkForNewFunctions();
 
   private Q_SLOTS:
       void parseNewVariables(Cantor::Expression::Status status);
       void parseNewFunctions(Cantor::Expression::Status status);
 
   Q_SIGNALS:
       void variablesAdded(const QStringList variables);
       void variablesRemoved(const QStringList variables);
 
       void functionsAdded(const QStringList variables);
       void functionsRemoved(const QStringList variables);
 
   private:
     MaximaSession* maximaSession();
 
   private:
     QList<Variable> m_variables;
     QList<Variable> m_functions;
 
 };
 
 #endif /* _MAXIMAVARIABLEMODEL_H */
diff --git a/src/lib/defaultvariablemodel.cpp b/src/lib/defaultvariablemodel.cpp
index 2efdb011..29c55bfe 100644
--- a/src/lib/defaultvariablemodel.cpp
+++ b/src/lib/defaultvariablemodel.cpp
@@ -1,197 +1,193 @@
 /*
     This program 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 2
     of the License, or (at your option) any later version.
 
     This program 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 this program; if not, write to the Free Software
     Foundation, Inc., 51 Franklin Street, Fifth Floor,
     Boston, MA  02110-1301, USA.
 
     ---
     Copyright (C) 2010 Miha Čančula <miha.cancula@gmail.com>
  */
 
 #include "defaultvariablemodel.h"
 #include <QDebug>
 #include <KLocalizedString>
 #include "extension.h"
 #include "backend.h"
 
 namespace Cantor
 {
 
 class DefaultVariableModelPrivate
 {
 public:
     QList<DefaultVariableModel::Variable> variables;
 
     Session* session;
     VariableManagementExtension* extension;
 };
 
 DefaultVariableModel::DefaultVariableModel(Session* session): QAbstractTableModel(session),
 d_ptr(new DefaultVariableModelPrivate)
 {
     Q_D(DefaultVariableModel);
     d->session = session;
     if (session)
     {
         d->extension = dynamic_cast<Cantor::VariableManagementExtension*>(session->backend()->extension(QLatin1String("VariableManagementExtension")));
     }
     qDebug() << d->session << d->extension;
 }
 
 int DefaultVariableModel::columnCount(const QModelIndex& parent) const
 {
     Q_UNUSED(parent);
     return ColumnCount;
 }
 
 int DefaultVariableModel::rowCount(const QModelIndex& parent) const
 {
     if (parent.isValid())
     {
         return 0;
     }
     else
     {
         Q_D(const DefaultVariableModel);
         return d->variables.size();
     }
 }
+
 QVariant DefaultVariableModel::headerData(int section, Qt::Orientation orientation, int role) const
 {
     if(role==Qt::DisplayRole && orientation==Qt::Horizontal) {
         switch(section) {
             case NameColumn:
                 return i18nc("@title:column", "Name");
 
             case ValueColumn:
                 return i18nc("@title:column", "Value");
                 break;
         }
     }
     return QVariant();
 }
 
 Qt::ItemFlags DefaultVariableModel::flags(const QModelIndex& index) const
 {
     return QAbstractItemModel::flags(index) | Qt::ItemIsEditable;
 }
 
-
 QVariant DefaultVariableModel::data(const QModelIndex& index, int role) const
 {
     if (role != Qt::DisplayRole || !index.isValid())
     {
         return QVariant();
     }
 
     Q_D(const DefaultVariableModel);
     switch (index.column())
     {
         case NameColumn:
             return QVariant(d->variables[index.row()].name);
         case ValueColumn:
             return QVariant(d->variables[index.row()].value);
         default:
             return QVariant();
     }
 }
 
 bool DefaultVariableModel::setData(const QModelIndex& index, const QVariant& value, int role)
 {
     if(role!=Qt::EditRole || !value.isValid() || !index.isValid())
     {
         return false;
     }
 
     Q_D(const DefaultVariableModel);
     if(index.column() == ValueColumn)
     {
         // Changing values
         QString name = data(index.sibling(index.row(), NameColumn)).toString();
         d->session->evaluateExpression(d->extension->setValue(name, value.toString()), Expression::DeleteOnFinish);
         return true;
     }
     else if(index.column() == NameColumn)
     {
         // Renaming => copy it, then delete the old one
         QString oldName = data(index).toString();
         QString variableValue = data(index.sibling(index.row(), ValueColumn)).toString();
         d->session->evaluateExpression(d->extension->addVariable(value.toString(), variableValue), Expression::DeleteOnFinish);
         d->session->evaluateExpression(d->extension->removeVariable(oldName), Expression::DeleteOnFinish);
         return true;
     }
     return false;
 }
 
-
 void DefaultVariableModel::addVariable(const QString& name, const QString& value)
 {
     Variable v;
     v.name = name;
     v.value = value;
     addVariable(v);
 }
 
 void DefaultVariableModel::addVariable(const Cantor::DefaultVariableModel::Variable& variable)
 {
     Q_D(DefaultVariableModel);
     if ( d->variables.contains(variable) )
     {
         removeVariable(variable);
     }
     beginInsertRows(QModelIndex(), d->variables.size(), d->variables.size());
     d->variables.append(variable);
     endInsertRows();
 }
 
 void DefaultVariableModel::removeVariable(const QString& name)
 {
     Variable v;
     v.name = name;
     removeVariable(v);
 }
 
 void DefaultVariableModel::removeVariable(const Cantor::DefaultVariableModel::Variable& variable)
 {
     Q_D(DefaultVariableModel);
     int row = d->variables.indexOf(variable);
     if(row==-1)
         return;
     beginRemoveRows(QModelIndex(), row, row);
     d->variables.removeAt(row);
     endRemoveRows();
 }
 
 void DefaultVariableModel::clearVariables()
 {
     Q_D(DefaultVariableModel);
     beginResetModel();
     d->variables.clear();
     endResetModel();
 }
 
 Session* DefaultVariableModel::session() const
 {
     Q_D(const DefaultVariableModel);
     return d->session;
 }
 
 bool operator==(const Cantor::DefaultVariableModel::Variable& one, const Cantor::DefaultVariableModel::Variable& other)
 {
     return one.name == other.name;
 }
 
 }
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