diff --git a/src/backends/maxima/maximavariablemodel.h b/src/backends/maxima/maximavariablemodel.h
--- a/src/backends/maxima/maximavariablemodel.h
+++ b/src/backends/maxima/maximavariablemodel.h
@@ -38,10 +38,8 @@
 
     void clear();
 
-    QList<Variable> variables();
     QList<Variable> functions();
 
-    QStringList variableNames();
     QStringList functionNames(bool stripParameters=false);
 
     bool isUpdateCommand(const QString &cmd) const;
@@ -53,17 +51,13 @@
       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;
     Cantor::Expression* m_variableExpression;
     Cantor::Expression* m_functionExpression;
diff --git a/src/backends/maxima/maximavariablemodel.cpp b/src/backends/maxima/maximavariablemodel.cpp
--- a/src/backends/maxima/maximavariablemodel.cpp
+++ b/src/backends/maxima/maximavariablemodel.cpp
@@ -39,9 +39,7 @@
 void MaximaVariableModel::clear()
 {
     emit functionsRemoved(functionNames());
-    emit variablesRemoved(variableNames());
     m_functions.clear();
-    m_variables.clear();
     DefaultVariableModel::clearVariables();
 }
 
@@ -143,43 +141,10 @@
     MaximaExpression* expr=static_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;
+    setVariables(newVars);
 
     //the expression is not needed anymore
     expr->deleteLater();
-
-    emit variablesAdded(addedVars);
-    emit variablesRemoved(removedVars);
 }
 
 void MaximaVariableModel::parseNewFunctions(Cantor::Expression::Status status)
@@ -243,25 +208,11 @@
     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;
diff --git a/src/lib/defaultvariablemodel.h b/src/lib/defaultvariablemodel.h
--- a/src/lib/defaultvariablemodel.h
+++ b/src/lib/defaultvariablemodel.h
@@ -84,6 +84,16 @@
      */
     Session* session() const;
 
+    /**
+     * Returns variables, stored in this model, as @see Variable.
+     */
+    QList<Variable> variables() const;
+
+    /**
+     * Returns names of stored variables
+     */
+    QStringList variableNames() const;
+
 public Q_SLOTS:
     /**
      * Adds a variable to the model.
@@ -113,6 +123,18 @@
      */
     void clearVariables();
 
+Q_SIGNALS:
+    /**
+     * Emitted after adding new variables
+     * @param variables list of new variables
+     */
+    void variablesAdded(const QStringList& variables);
+
+    /**
+     * Emitted after variables removing
+     * @param variables list of removed variables
+     */
+    void variablesRemoved(const QStringList& variables);
 
 protected:
     QVariant data(const QModelIndex& index, int role = Qt::DisplayRole) const override;
@@ -123,6 +145,8 @@
     QVariant headerData(int section, Qt::Orientation orientation, int role = Qt::DisplayRole) const override;
     Qt::ItemFlags flags(const QModelIndex& index) const override;
 
+    void setVariables(const QList<DefaultVariableModel::Variable>& newVars);
+
     enum Column
     {
         NameColumn = 0,
diff --git a/src/lib/defaultvariablemodel.cpp b/src/lib/defaultvariablemodel.cpp
--- a/src/lib/defaultvariablemodel.cpp
+++ b/src/lib/defaultvariablemodel.cpp
@@ -146,10 +146,12 @@
     Q_D(DefaultVariableModel);
     if ( d->variables.contains(variable) )
     {
+        // TODO: Why we remove variable here?
         removeVariable(variable);
     }
     beginInsertRows(QModelIndex(), d->variables.size(), d->variables.size());
     d->variables.append(variable);
+    emit variablesAdded(QStringList(variable.name));
     endInsertRows();
 }
 
@@ -166,25 +168,104 @@
     int row = d->variables.indexOf(variable);
     if(row==-1)
         return;
+    const QString& name = variable.name;
     beginRemoveRows(QModelIndex(), row, row);
     d->variables.removeAt(row);
     endRemoveRows();
+    emit variablesRemoved(QStringList(name));
 }
 
 void DefaultVariableModel::clearVariables()
 {
     Q_D(DefaultVariableModel);
     beginResetModel();
+
+    QStringList names;
+    for (const Variable var: d->variables)
+        names.append(var.name);
+
     d->variables.clear();
     endResetModel();
+
+    emit variablesRemoved(names);
+}
+
+void DefaultVariableModel::setVariables(const QList<DefaultVariableModel::Variable>& newVars)
+{
+    Q_D(DefaultVariableModel);
+
+    QStringList addedVars;
+    QStringList removedVars;
+
+    // Handle deleted vars
+    for (const Variable var : variables())
+    {
+        bool found = false;
+        for (const Variable& newvar : newVars)
+            if(var.name == newvar.name)
+            {
+                found=true;
+                break;
+            }
+
+        if (!found)
+            removedVars << var.name;
+    }
+
+    // Handle added vars
+    const int size = d->variables.size();
+    for (const Variable newvar : newVars)
+    {
+        bool found = false;
+        for (int i = 0; i < size; i++)
+            if(d->variables[i].name == newvar.name)
+            {
+                found=true;
+                break;
+            }
+
+        if (!found)
+        {
+            addedVars << newvar.name;
+            beginInsertRows(QModelIndex(), d->variables.size(), d->variables.size());
+            d->variables.append(newvar);
+            endInsertRows();
+        }
+    }
+
+    for (const QString& var: removedVars)
+    {
+        int row = d->variables.indexOf(Variable{var,QString()});
+        beginRemoveRows(QModelIndex(), row, row);
+        d->variables.removeAt(row);
+        endRemoveRows();
+    }
+
+    emit variablesAdded(addedVars);
+    emit variablesRemoved(removedVars);
 }
 
 Session* DefaultVariableModel::session() const
 {
     Q_D(const DefaultVariableModel);
     return d->session;
 }
 
+QList<DefaultVariableModel::Variable> DefaultVariableModel::variables() const
+{
+    Q_D(const DefaultVariableModel);
+    return d->variables;
+}
+
+QStringList DefaultVariableModel::variableNames() const
+{
+    Q_D(const DefaultVariableModel);
+    QStringList names;
+    for (const Variable var: d->variables)
+        names << var.name;
+    return names;
+}
+
 bool operator==(const Cantor::DefaultVariableModel::Variable& one, const Cantor::DefaultVariableModel::Variable& other)
 {
     return one.name == other.name;