diff --git a/apps/code/python_toolbox.cpp b/apps/code/python_toolbox.cpp
index 070470576..3ceeaf2ad 100644
--- a/apps/code/python_toolbox.cpp
+++ b/apps/code/python_toolbox.cpp
@@ -294,8 +294,7 @@ bool PythonToolbox::selectLeaf(ToolboxMessageTree * selectedMessageTree) {
   int strippedEditedTextMaxLength = strlen(editedText)+1;
   char strippedEditedText[strippedEditedTextMaxLength];
   Shared::ToolboxHelpers::TextToInsertForCommandMessage(node->insertedText(), strippedEditedText, strippedEditedTextMaxLength);
-  TextInput * textInput = static_cast<TextInput *>(sender());
-  textInput->handleEventWithText(strippedEditedText, true);
+  sender()->handleEventWithText(strippedEditedText, true);
   app()->dismissModalViewController();
   return true;
 }
diff --git a/apps/code/python_toolbox.h b/apps/code/python_toolbox.h
index 5d9dab80f..03c48ebf0 100644
--- a/apps/code/python_toolbox.h
+++ b/apps/code/python_toolbox.h
@@ -10,10 +10,7 @@ namespace Code {
 
 class PythonToolbox : public Toolbox {
 public:
-  typedef void (*Action)(void * sender, const char * text);
   PythonToolbox();
-
-  // StackViewController
   bool handleEvent(Ion::Events::Event event) override;
 protected:
   KDCoordinate rowHeight(int j) override;
diff --git a/apps/math_toolbox.cpp b/apps/math_toolbox.cpp
index f452663fb..62337c781 100644
--- a/apps/math_toolbox.cpp
+++ b/apps/math_toolbox.cpp
@@ -108,67 +108,21 @@ const ToolboxMessageTree toolboxModel = ToolboxMessageTree(I18n::Message::Toolbo
 #endif
 
 MathToolbox::MathToolbox() :
-  Toolbox(nullptr, I18n::translate(rootModel()->label())),
-  m_action(actionForTextInput)
+  Toolbox(nullptr, I18n::translate(rootModel()->label()))
 {
 }
 
-void MathToolbox::setSenderAndAction(Responder * sender, Action action) {
-  setSender(sender);
-  m_action = action;
-}
-
-void MathToolbox::actionForExpressionLayoutField(void * sender, const char * text, bool removeArguments) {
-  ExpressionLayoutField * expressionLayoutEditorSender = static_cast<ExpressionLayoutField *>(sender);
-  Expression * resultExpression = nullptr;
-  if (removeArguments) {
-    // Replace the arguments with Empty chars.
-    int textToInsertMaxLength = strlen(text);
-    char textToInsert[textToInsertMaxLength];
-    Shared::ToolboxHelpers::TextToParseIntoLayoutForCommandText(text, textToInsert, textToInsertMaxLength);
-    // Create the layout
-    resultExpression = Expression::parse(textToInsert);
-  } else {
-    resultExpression = Expression::parse(text);
-  }
-  if (resultExpression == nullptr) {
-    return;
-  }
-  ExpressionLayout * resultLayout = resultExpression->createLayout();
-  // Find the pointed layout.
-  ExpressionLayout * pointedLayout = nullptr;
-  if (resultLayout->isHorizontal()) {
-    // If the layout is horizontal, pick the first open parenthesis.
-    // For now, all horizontal layouts in MathToolbox have parentheses.
-    for (int i = 0; i < resultLayout->numberOfChildren(); i++) {
-      if (resultLayout->editableChild(i)->isLeftParenthesis()) {
-        pointedLayout = resultLayout->editableChild(i);
-        break;
-      }
-    }
-  }
-  // Insert the layout. If pointedLayout is nullptr, the cursor will be on the
-  // right of the inserted layout.
-  expressionLayoutEditorSender->insertLayoutAtCursor(resultLayout, pointedLayout);
-}
-
-void MathToolbox::actionForTextInput(void * sender, const char * text, bool removeArguments) {
-  TextInput * textInputSender = static_cast<TextInput *>(sender);
-  if (removeArguments) {
-    int maxTextToInsertLength = strlen(text);
-    char textToInsert[maxTextToInsertLength];
-    // Translate the message and remove the arguments.
-    Shared::ToolboxHelpers::TextToInsertForCommandText(text, textToInsert, maxTextToInsertLength);
-    textInputSender->handleEventWithText(textToInsert);
-  } else {
-    textInputSender->handleEventWithText(text);
-  }
-}
-
 bool MathToolbox::selectLeaf(ToolboxMessageTree * selectedMessageTree) {
   ToolboxMessageTree * messageTree = selectedMessageTree;
   m_selectableTableView.deselectTable();
-  m_action(sender(), I18n::translate(messageTree->insertedText()), true);
+
+  // Translate the message and remove the arguments
+  const char * text = I18n::translate(messageTree->insertedText());
+  int maxTextToInsertLength = strlen(text) + 1;
+  char textToInsert[maxTextToInsertLength];
+  Shared::ToolboxHelpers::TextToInsertForCommandText(text, textToInsert, maxTextToInsertLength, true);
+
+  sender()->handleEventWithText(textToInsert);
   app()->dismissModalViewController();
   return true;
 }
diff --git a/apps/math_toolbox.h b/apps/math_toolbox.h
index 6079054e2..fd7f1ad7a 100644
--- a/apps/math_toolbox.h
+++ b/apps/math_toolbox.h
@@ -7,11 +7,7 @@
 
 class MathToolbox : public Toolbox {
 public:
-  typedef void (*Action)(void * sender, const char * text, bool removeArguments);
   MathToolbox();
-  void setSenderAndAction(Responder * sender, Action action);
-  static void actionForExpressionLayoutField(void * sender, const char * text, bool removeArguments = true);
-  static void actionForTextInput(void * sender, const char * text, bool removeArguments = true);
 protected:
   bool selectLeaf(ToolboxMessageTree * selectedMessageTree) override;
   const ToolboxMessageTree * rootModel() override;
@@ -19,7 +15,6 @@ protected:
   MessageTableCellWithChevron* nodeCellAtIndex(int index) override;
   int maxNumberOfDisplayedRows() override;
   constexpr static int k_maxNumberOfDisplayedRows = 6; // = 240/40
-  Action m_action;
 private:
   MessageTableCellWithMessage m_leafCells[k_maxNumberOfDisplayedRows];
   MessageTableCellWithChevron m_nodeCells[k_maxNumberOfDisplayedRows];
diff --git a/apps/sequence/list/list_controller.cpp b/apps/sequence/list/list_controller.cpp
index f570661b7..e253542ba 100644
--- a/apps/sequence/list/list_controller.cpp
+++ b/apps/sequence/list/list_controller.cpp
@@ -24,15 +24,11 @@ const char * ListController::title() {
 }
 
 Toolbox * ListController::toolboxForTextInput(TextInput * textInput) {
-  setToolboxExtraCells();
-  m_sequenceToolbox.setSenderAndAction(textInput, MathToolbox::actionForTextInput);
-  return &m_sequenceToolbox;
+  return toolbox(textInput);
 }
 
 Toolbox * ListController::toolboxForExpressionLayoutField(ExpressionLayoutField * expressionLayoutField) {
-  setToolboxExtraCells();
-  m_sequenceToolbox.setSenderAndAction(expressionLayoutField, MathToolbox::actionForExpressionLayoutField);
-  return &m_sequenceToolbox;
+  return toolbox(expressionLayoutField);
 }
 
 TextFieldDelegateApp * ListController::textFieldDelegateApp() {
@@ -87,6 +83,20 @@ void ListController::selectPreviousNewSequenceCell() {
   }
 }
 
+Toolbox * ListController::toolbox(Responder * sender) {
+  // Set extra cells
+  int recurrenceDepth = -1;
+  int sequenceDefinition = sequenceDefinitionForRow(selectedRow());
+  Sequence * sequence = m_sequenceStore->functionAtIndex(functionIndexForRow(selectedRow()));
+  if (sequenceDefinition == 0) {
+    recurrenceDepth = sequence->numberOfElements()-1;
+  }
+  m_sequenceToolbox.setExtraCells(sequence->name(), recurrenceDepth);
+  // Set sender
+  m_sequenceToolbox.setSender(sender);
+  return &m_sequenceToolbox;
+}
+
 void ListController::editExpression(Sequence * sequence, int sequenceDefinition, Ion::Events::Event event) {
   char * initialText = nullptr;
   char initialTextContent[TextField::maxBufferSize()];
@@ -309,14 +319,4 @@ void ListController::unloadView(View * view) {
   Shared::ListController::unloadView(view);
 }
 
-void ListController::setToolboxExtraCells() {
-  int recurrenceDepth = -1;
-  int sequenceDefinition = sequenceDefinitionForRow(selectedRow());
-  Sequence * sequence = m_sequenceStore->functionAtIndex(functionIndexForRow(selectedRow()));
-  if (sequenceDefinition == 0) {
-    recurrenceDepth = sequence->numberOfElements()-1;
-  }
-  m_sequenceToolbox.setExtraCells(sequence->name(), recurrenceDepth);
-}
-
 }
diff --git a/apps/sequence/list/list_controller.h b/apps/sequence/list/list_controller.h
index 07c6f68bd..658292e21 100644
--- a/apps/sequence/list/list_controller.h
+++ b/apps/sequence/list/list_controller.h
@@ -26,6 +26,7 @@ public:
   Toolbox * toolboxForExpressionLayoutField(ExpressionLayoutField * expressionLayoutField) override;
   void selectPreviousNewSequenceCell();
 private:
+  Toolbox * toolbox(Responder * sender);
   Shared::TextFieldDelegateApp * textFieldDelegateApp() override;
   Shared::ExpressionFieldDelegateApp * expressionFieldDelegateApp() override;
   void editExpression(Sequence * sequence, int sequenceDefinitionIndex, Ion::Events::Event event);
@@ -44,7 +45,6 @@ private:
   void reinitExpression(Shared::Function * function) override;
   View * loadView() override;
   void unloadView(View * view) override;
-  void setToolboxExtraCells();
   static constexpr KDCoordinate k_emptySubRowHeight = 30;
   constexpr static int k_maxNumberOfRows = 3*MaxNumberOfSequences;
   SequenceStore * m_sequenceStore;
diff --git a/apps/sequence/list/sequence_toolbox.cpp b/apps/sequence/list/sequence_toolbox.cpp
index 08d67f4fd..b27604498 100644
--- a/apps/sequence/list/sequence_toolbox.cpp
+++ b/apps/sequence/list/sequence_toolbox.cpp
@@ -114,26 +114,7 @@ bool SequenceToolbox::selectAddedCell(int selectedRow){
   int bufferSize = 10;
   char buffer[bufferSize];
   m_addedCellLayout[selectedRow]->writeTextInBuffer(buffer, bufferSize);
-  if (m_action == MathToolbox::actionForTextInput) {
-    /* DIRTY. The symbols are layouted using a Subscript VerticalOffsetLayout,
-     * which serializes into "_{}", but we want parentheses for text fields. We
-     * thus need to remove any underscores, and changes brackets into
-     * parentheses. */
-    for (int i = 0; i < bufferSize; i++) {
-      if (buffer[i] == '{') {
-        buffer[i] = '(';
-      }
-      if (buffer[i] == '}') {
-        buffer[i] = ')';
-      }
-      if (buffer[i] == '_') {
-        memmove(&buffer[i], &buffer[i+1], bufferSize - (i+1) + 1);
-        bufferSize--;
-        i--;
-      }
-    }
-  }
-  m_action(sender(), buffer, false);
+  sender()->handleEventWithText(buffer);
   app()->dismissModalViewController();
   return true;
 }
diff --git a/apps/shared/expression_field_delegate_app.cpp b/apps/shared/expression_field_delegate_app.cpp
index 870b4e351..d3474691a 100644
--- a/apps/shared/expression_field_delegate_app.cpp
+++ b/apps/shared/expression_field_delegate_app.cpp
@@ -49,7 +49,7 @@ bool ExpressionFieldDelegateApp::expressionLayoutFieldDidReceiveEvent(Expression
 
 Toolbox * ExpressionFieldDelegateApp::toolboxForExpressionLayoutField(ExpressionLayoutField * expressionLayoutField) {
   Toolbox * toolbox = container()->mathToolbox();
-  static_cast<MathToolbox *>(toolbox)->setSenderAndAction(expressionLayoutField, MathToolbox::actionForExpressionLayoutField);
+  toolbox->setSender(expressionLayoutField);
   return toolbox;
 }
 
diff --git a/apps/shared/text_field_delegate_app.cpp b/apps/shared/text_field_delegate_app.cpp
index 3e92edd1f..f9eda1ed4 100644
--- a/apps/shared/text_field_delegate_app.cpp
+++ b/apps/shared/text_field_delegate_app.cpp
@@ -109,7 +109,7 @@ bool TextFieldDelegateApp::textFieldDidReceiveEvent(TextField * textField, Ion::
 
 Toolbox * TextFieldDelegateApp::toolboxForTextInput(TextInput * textInput) {
   Toolbox * toolbox = container()->mathToolbox();
-  static_cast<MathToolbox *>(toolbox)->setSenderAndAction(textInput, MathToolbox::actionForTextInput);
+  toolbox->setSender(textInput);
   return toolbox;
 }
 
diff --git a/apps/shared/toolbox_helpers.cpp b/apps/shared/toolbox_helpers.cpp
index ee39e138d..0a0e50035 100644
--- a/apps/shared/toolbox_helpers.cpp
+++ b/apps/shared/toolbox_helpers.cpp
@@ -8,7 +8,8 @@ namespace Shared {
 namespace ToolboxHelpers {
 
 int CursorIndexInCommandText(const char * text) {
-  for (size_t i = 0; i < strlen(text); i++) {
+  size_t textLength = strlen(text);
+  for (size_t i = 0; i < textLength; i++) {
     if (text[i] == '(' || text[i] == '\'') {
       return i + 1;
     }
@@ -16,7 +17,7 @@ int CursorIndexInCommandText(const char * text) {
       return i;
     }
   }
-  return strlen(text);
+  return textLength;
 }
 
 void TextToInsertForCommandMessage(I18n::Message message, char * buffer, int bufferSize, bool replaceArgsWithEmptyChar) {
@@ -65,13 +66,5 @@ void TextToInsertForCommandText(const char * command, char * buffer, int bufferS
   buffer[currentNewTextIndex] = 0;
 }
 
-void TextToParseIntoLayoutForCommandMessage(I18n::Message message, char * buffer, int bufferSize) {
-  TextToParseIntoLayoutForCommandText(I18n::translate(message), buffer, bufferSize);
-}
-
-void TextToParseIntoLayoutForCommandText(const char * command, char * buffer, int bufferSize) {
-  TextToInsertForCommandText(command, buffer, bufferSize, true);
-}
-
 }
 }
diff --git a/apps/shared/toolbox_helpers.h b/apps/shared/toolbox_helpers.h
index ae8226644..16233ffe6 100644
--- a/apps/shared/toolbox_helpers.h
+++ b/apps/shared/toolbox_helpers.h
@@ -17,9 +17,6 @@ void TextToInsertForCommandMessage(I18n::Message message, char * buffer, int buf
 void TextToInsertForCommandText(const char * command, char * buffer, int bufferSize, bool replaceArgsWithEmptyChar = false);
 /* Removes the arguments from a command:
  *  - Removes text between parentheses or brackets, except commas */
-void TextToParseIntoLayoutForCommandMessage(I18n::Message message, char * buffer, int bufferSize);
-void TextToParseIntoLayoutForCommandText(const char * command, char * buffer, int bufferSize);
-/* Removes the arguments from a command and replaces them with empty chars. */
 
 }
 }
diff --git a/escher/include/escher/expression_field.h b/escher/include/escher/expression_field.h
index d47f11317..ae8238b6c 100644
--- a/escher/include/escher/expression_field.h
+++ b/escher/include/escher/expression_field.h
@@ -7,7 +7,7 @@
 #include <escher/text_field_delegate.h>
 #include <poincare/expression_layout.h>
 
-class ExpressionField :  public Responder, public View {
+class ExpressionField : public Responder, public View {
 public:
   ExpressionField(Responder * parentResponder, char * textBuffer, int textBufferLength, Poincare::ExpressionLayout * layout, TextFieldDelegate * textFieldDelegate, ExpressionLayoutFieldDelegate * expressionLayoutFieldDelegate);
 
@@ -20,6 +20,7 @@ public:
   bool editionIsInTextField() const;
   bool isEmpty() const;
   bool heightIsMaximal() const;
+  bool handleEventWithText(const char * text, bool indentation = false) override;
 
   /* View */
   int numberOfSubviews() const override { return 1; }
diff --git a/escher/include/escher/expression_layout_field.h b/escher/include/escher/expression_layout_field.h
index 76a3cfa48..48e01d365 100644
--- a/escher/include/escher/expression_layout_field.h
+++ b/escher/include/escher/expression_layout_field.h
@@ -20,6 +20,7 @@ public:
   void reload();
   bool hasText() const;
   void writeTextInBuffer(char * buffer, int bufferLength);
+  bool handleEventWithText(const char * text, bool indentation = false);
   Poincare::ExpressionLayout * expressionLayout();
 
   /* Responder */
diff --git a/escher/include/escher/responder.h b/escher/include/escher/responder.h
index 691c4c208..45deaa8b9 100644
--- a/escher/include/escher/responder.h
+++ b/escher/include/escher/responder.h
@@ -10,6 +10,7 @@ class Responder {
 public:
   Responder(Responder * parentResponder);
   virtual bool handleEvent(Ion::Events::Event event); // Default implementation does nothing
+  virtual bool handleEventWithText(const char * text, bool indentation = false) { return false; }
   virtual void didBecomeFirstResponder();
   virtual void willResignFirstResponder();
   virtual void didEnterResponderChain(Responder * previousFirstResponder);
diff --git a/escher/include/escher/text_input.h b/escher/include/escher/text_input.h
index 441bc33d0..136fb77b9 100644
--- a/escher/include/escher/text_input.h
+++ b/escher/include/escher/text_input.h
@@ -19,7 +19,6 @@ public:
   size_t cursorLocation() const { return nonEditableContentView()->cursorLocation(); }
   bool setCursorLocation(int location);
   virtual void scrollToCursor();
-  virtual bool handleEventWithText(const char * text, bool indenting = false) = 0;
 protected:
   class ContentView : public View {
   public:
diff --git a/escher/include/escher/text_input_helpers.h b/escher/include/escher/text_input_helpers.h
index cb216bdaa..219eaba74 100644
--- a/escher/include/escher/text_input_helpers.h
+++ b/escher/include/escher/text_input_helpers.h
@@ -8,12 +8,9 @@ namespace TextInputHelpers {
 int CursorIndexInCommand(const char * text);
 /* Returns the index of the cursor position in a Command, which is the smallest
  * index between :
- *   - After the first open parenthesis/quote if the following element is
- *   either a quote, a coma or a parenthesi
- *   - The end of the text
- *   - Special case: when the text preceding the parenthesis is 'random', the
- *   cursor position is the end of the text. */
-constexpr static const char * k_random = "random";
+ *   - The first EmptyChar index (which is the position of the first argument)
+ *   - The first empty quote
+ *   - The end of the text */
 }
 
 #endif
diff --git a/escher/include/escher/toolbox.h b/escher/include/escher/toolbox.h
index 30a87bd22..7c4f22bb5 100644
--- a/escher/include/escher/toolbox.h
+++ b/escher/include/escher/toolbox.h
@@ -12,7 +12,7 @@
 class Toolbox : public StackViewController, public ListViewDataSource, public SelectableTableViewDataSource {
 public:
   Toolbox(Responder * parentResponder, const char * title = 0);
-  void setSender(Responder * sender);
+  void setSender(Responder * sender) { m_sender = sender; }
 
   // StackViewController
   bool handleEvent(Ion::Events::Event event) override;
@@ -72,7 +72,7 @@ protected:
   bool handleEventForRow(Ion::Events::Event event, int selectedRow);
   bool selectSubMenu(ToolboxMessageTree * selectedMessageTree);
   bool returnToPreviousMenu();
-  virtual Responder * sender();
+  Responder * sender() { return m_sender; }
   virtual bool selectLeaf(ToolboxMessageTree * selectedMessageTree) = 0;
   virtual const ToolboxMessageTree * rootModel() = 0;
   virtual MessageTableCellWithMessage * leafCellAtIndex(int index) = 0;
diff --git a/escher/src/expression_field.cpp b/escher/src/expression_field.cpp
index 1576268d3..1420db5e0 100644
--- a/escher/src/expression_field.cpp
+++ b/escher/src/expression_field.cpp
@@ -109,6 +109,14 @@ bool ExpressionField::heightIsMaximal() const {
   return inputViewHeight() == k_separatorThickness + k_verticalExpressionViewMargin + maximalHeight();
 }
 
+bool ExpressionField::handleEventWithText(const char * text, bool indentation) {
+  if (editionIsInTextField()) {
+    return m_textField.handleEventWithText(text, indentation);
+  } else {
+    return m_expressionLayoutField.handleEventWithText(text, indentation);
+  }
+}
+
 KDCoordinate ExpressionField::inputViewHeight() const {
   if (editionIsInTextField()) {
     return k_separatorThickness + k_textFieldHeight;
diff --git a/escher/src/expression_layout_field.cpp b/escher/src/expression_layout_field.cpp
index 4bbdd6a6c..e56457672 100644
--- a/escher/src/expression_layout_field.cpp
+++ b/escher/src/expression_layout_field.cpp
@@ -1,9 +1,11 @@
 #include <escher/expression_layout_field.h>
 #include <escher/clipboard.h>
 #include <escher/text_field.h>
-#include <poincare/src/layout/matrix_layout.h>
+#include <poincare/expression.h>
 #include <poincare/expression_layout_cursor.h>
+#include <poincare/src/layout/matrix_layout.h>
 #include <assert.h>
+#include <string.h>
 
 ExpressionLayoutField::ExpressionLayoutField(Responder * parentResponder, Poincare::ExpressionLayout * expressionLayout, ExpressionLayoutFieldDelegate * delegate) :
   ScrollableView(parentResponder, &m_contentView, this),
@@ -254,6 +256,47 @@ void ExpressionLayoutField::writeTextInBuffer(char * buffer, int bufferLength) {
   m_contentView.expressionView()->expressionLayout()->writeTextInBuffer(buffer, bufferLength);
 }
 
+bool ExpressionLayoutField::handleEventWithText(const char * text, bool indentation) {
+  size_t textLength = strlen(text) + 1;
+  size_t textToInsertMaxLength = 2*textLength;
+  char textToInsert[textToInsertMaxLength];
+
+  size_t textToInsertIndex = 0;
+  // Add empty chars where arguments are needed
+  for (size_t i = textToInsertIndex; i < textLength; i++) {
+    textToInsert[textToInsertIndex++] = text[i];
+    if (((text[i] == '(' || text[i] == '[')
+          && text[i+1] == ',')
+        || (text[i] == ','
+          && (text[i+1] == ')' || text[i+1] == ']')))
+    {
+      textToInsert[textToInsertIndex++] = Ion::Charset::Empty;
+    }
+  }
+
+  Poincare::Expression * resultExpression = Poincare::Expression::parse(textToInsert);
+  if (resultExpression == nullptr) {
+    return false;
+  }
+  Poincare::ExpressionLayout * resultLayout = resultExpression->createLayout();
+  // Find the pointed layout.
+  Poincare::ExpressionLayout * pointedLayout = nullptr;
+  if (resultLayout->isHorizontal()) {
+    /* If the layout is horizontal, pick the first open parenthesis. For now,
+     * all horizontal layouts in MathToolbox have parentheses. */
+    for (int i = 0; i < resultLayout->numberOfChildren(); i++) {
+      if (resultLayout->editableChild(i)->isLeftParenthesis()) {
+        pointedLayout = resultLayout->editableChild(i);
+        break;
+      }
+    }
+  }
+  /* Insert the layout. If pointedLayout is nullptr, the cursor will be on the
+   * right of the inserted layout. */
+  insertLayoutAtCursor(resultLayout, pointedLayout);
+  return true;
+}
+
 Poincare::ExpressionLayout * ExpressionLayoutField::expressionLayout() {
   return m_contentView.expressionView()->expressionLayout();
 }
diff --git a/escher/src/text_area.cpp b/escher/src/text_area.cpp
index 7512d6bac..656766c59 100644
--- a/escher/src/text_area.cpp
+++ b/escher/src/text_area.cpp
@@ -293,8 +293,22 @@ TextArea::TextArea(Responder * parentResponder, char * textBuffer,
 
 bool TextArea::handleEventWithText(const char * text, bool indentation) {
   int nextCursorLocation = cursorLocation();
-  if ((indentation && insertTextWithIndentation(text, cursorLocation())) || insertTextAtLocation(text, cursorLocation())) {
-    nextCursorLocation += TextInputHelpers::CursorIndexInCommand(text);
+
+  int cursorIndexInCommand = TextInputHelpers::CursorIndexInCommand(text);
+
+  size_t eventTextSize = strlen(text) + 1;
+  char buffer[eventTextSize];
+  size_t bufferIndex = 0;
+
+  // Remove EmptyChars
+  for (size_t i = bufferIndex; i < eventTextSize; i++) {
+    if (text[i] != Ion::Charset::Empty) {
+      buffer[bufferIndex++] = text[i];
+    }
+  }
+
+  if ((indentation && insertTextWithIndentation(buffer, cursorLocation())) || insertTextAtLocation(buffer, cursorLocation())) {
+    nextCursorLocation += cursorIndexInCommand;
   }
   setCursorLocation(nextCursorLocation);
   return true;
diff --git a/escher/src/text_field.cpp b/escher/src/text_field.cpp
index e37cc4576..1721b9ba5 100644
--- a/escher/src/text_field.cpp
+++ b/escher/src/text_field.cpp
@@ -1,6 +1,7 @@
 #include <escher/text_field.h>
 #include <escher/text_input_helpers.h>
 #include <escher/clipboard.h>
+#include <ion/charset.h>
 #include <assert.h>
 
 /* TextField::ContentView */
@@ -305,12 +306,41 @@ bool TextField::handleEventWithText(const char * eventText, bool indentation) {
   if (!isEditing()) {
     setEditing(true);
   }
+  size_t eventTextSize = strlen(eventText) + 1;
+  char buffer[eventTextSize];
+  size_t bufferIndex = 0;
+
+  /* DIRTY
+   * We use the notation "_{}" to indicate a subscript layout. In a text field,
+   * such a subscript should be written using parentheses. For instance: "u_{n}"
+   * should be inserted as "u(n)".
+   * We thus remove underscores and changes brackets into parentheses. */
+  for (size_t i = bufferIndex; i < eventTextSize; i++) {
+    if (eventText[i] == '{') {
+      buffer[bufferIndex++] = '(';
+    } else if (eventText[i] == '}') {
+      buffer[bufferIndex++] = ')';
+    } else if (eventText[i] != '_') {
+      buffer[bufferIndex++] = eventText[i];
+    }
+  }
+
+  int cursorIndexInCommand = TextInputHelpers::CursorIndexInCommand(eventText);
+
+  bufferIndex = 0;
+  // Remove EmptyChars
+  for (size_t i = bufferIndex; i < eventTextSize; i++) {
+    if (buffer[i] != Ion::Charset::Empty) {
+      buffer[bufferIndex++] = buffer[i];
+    }
+  }
+
   int nextCursorLocation = draftTextLength();
-  if (insertTextAtLocation(eventText, cursorLocation())) {
-    /* The cursor position depends on the text as we sometimes want to
-     * position the cursor at the end of the text and sometimes after the
-     * first parenthesis. */
-    nextCursorLocation = cursorLocation() + TextInputHelpers::CursorIndexInCommand(eventText);
+  if (insertTextAtLocation(buffer, cursorLocation())) {
+    /* The cursor position depends on the text as we sometimes want to position
+     * the cursor at the end of the text and sometimes after the first
+     * parenthesis. */
+    nextCursorLocation = cursorLocation() + cursorIndexInCommand;
   }
   setCursorLocation(nextCursorLocation);
   return m_delegate->textFieldDidHandleEvent(this, true, strlen(text()) != previousTextLength);
diff --git a/escher/src/text_input_helpers.cpp b/escher/src/text_input_helpers.cpp
index 1c6f88f0d..dd0307d42 100644
--- a/escher/src/text_input_helpers.cpp
+++ b/escher/src/text_input_helpers.cpp
@@ -1,20 +1,19 @@
 #include <escher/text_input_helpers.h>
+#include <ion/charset.h>
 #include <string.h>
 
 namespace TextInputHelpers {
 
 int CursorIndexInCommand(const char * text) {
-  for (size_t i = 0; i < strlen(text)-1; i++) {
-    if (text[i] == '(' || text[i] == '\'') {
-      if (text[i+1] == ')' || text[i+1] == '\'' || text[i+1] == ',') {
-        if (i >= strlen(k_random) && memcmp(&text[i-strlen(k_random)], k_random, strlen(k_random)) == 0) {
-          break;
-        }
-        return i + 1;
-      }
+  size_t textLength = strlen(text);
+  for (size_t i = 0; i < textLength - 1; i++) {
+    if (text[i] == '\'' &&  text[i+1] == '\'') {
+      return i + 1;
+    } else if (text[i] == Ion::Charset::Empty) {
+      return i;
     }
   }
-  return strlen(text);
+  return textLength;
 }
 
 }
diff --git a/escher/src/toolbox.cpp b/escher/src/toolbox.cpp
index c423a275d..8c1023009 100644
--- a/escher/src/toolbox.cpp
+++ b/escher/src/toolbox.cpp
@@ -94,10 +94,6 @@ Toolbox::Toolbox(Responder * parentResponder, const char * title) :
 {
 }
 
-void Toolbox::setSender(Responder * sender) {
-  m_sender = sender;
-}
-
 bool Toolbox::handleEvent(Ion::Events::Event event) {
   return handleEventForRow(event, selectedRow());
 }
@@ -232,7 +228,3 @@ bool Toolbox::returnToPreviousMenu() {
   app()->setFirstResponder(&m_listController);
   return true;
 }
-
-Responder * Toolbox::sender() {
-  return m_sender;
-}