diff --git a/MathPad/Base.lproj/MPDocument.xib b/MathPad/Base.lproj/MPDocument.xib
index 3c4c28c..155c0fe 100644
--- a/MathPad/Base.lproj/MPDocument.xib
+++ b/MathPad/Base.lproj/MPDocument.xib
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="5023" systemVersion="13A603" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES">
+<document type="com.apple.InterfaceBuilder3.Cocoa.XIB" version="3.0" toolsVersion="5056" systemVersion="13C64" targetRuntime="MacOSX.Cocoa" propertyAccessControl="none" useAutolayout="YES">
     <dependencies>
-        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="5023"/>
+        <plugIn identifier="com.apple.InterfaceBuilder.CocoaPlugin" version="5056"/>
     </dependencies>
     <objects>
         <customObject id="-2" userLabel="File's Owner" customClass="MPDocument">
@@ -11,29 +11,34 @@
         </customObject>
         <customObject id="-1" userLabel="First Responder" customClass="FirstResponder"/>
         <customObject id="-3" userLabel="Application"/>
-        <window title="Window" allowsToolTipsWhenApplicationIsInactive="NO" autorecalculatesKeyViewLoop="NO" releasedWhenClosed="NO" visibleAtLaunch="NO" animationBehavior="default" id="xOd-HO-29H" userLabel="Window">
+        <window title="MathPad" allowsToolTipsWhenApplicationIsInactive="NO" autorecalculatesKeyViewLoop="NO" releasedWhenClosed="NO" visibleAtLaunch="NO" animationBehavior="default" id="xOd-HO-29H" userLabel="Window">
             <windowStyleMask key="styleMask" titled="YES" closable="YES" miniaturizable="YES" resizable="YES"/>
             <windowPositionMask key="initialPositionMask" leftStrut="YES" rightStrut="YES" topStrut="YES" bottomStrut="YES"/>
-            <rect key="contentRect" x="133" y="235" width="507" height="413"/>
-            <rect key="screenRect" x="0.0" y="0.0" width="1680" height="1028"/>
+            <rect key="contentRect" x="133" y="235" width="507" height="240"/>
+            <rect key="screenRect" x="0.0" y="0.0" width="1920" height="1058"/>
             <value key="minSize" type="size" width="94" height="86"/>
             <view key="contentView" id="gIp-Ho-8D9">
-                <rect key="frame" x="0.0" y="0.0" width="507" height="413"/>
+                <rect key="frame" x="0.0" y="0.0" width="507" height="240"/>
                 <autoresizingMask key="autoresizingMask"/>
                 <subviews>
-                    <textField verticalHuggingPriority="750" horizontalCompressionResistancePriority="250" translatesAutoresizingMaskIntoConstraints="NO" id="Hz6-mo-xeY">
-                        <rect key="frame" x="119" y="195" width="268" height="22"/>
-                        <autoresizingMask key="autoresizingMask"/>
-                        <textFieldCell key="cell" sendsActionOnEndEditing="YES" alignment="center" title="Your document contents here" id="JDq-Ah-v2f">
-                            <font key="font" metaFont="system" size="18"/>
-                            <color key="textColor" name="controlTextColor" catalog="System" colorSpace="catalog"/>
-                            <color key="backgroundColor" name="controlColor" catalog="System" colorSpace="catalog"/>
-                        </textFieldCell>
-                    </textField>
+                    <customView translatesAutoresizingMaskIntoConstraints="NO" id="fqc-IQ-ceJ" customClass="MPExpressionView">
+                        <rect key="frame" x="20" y="124" width="467" height="96"/>
+                        <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
+                    </customView>
+                    <customView translatesAutoresizingMaskIntoConstraints="NO" id="lcd-Ip-jjR" customClass="MPExpressionView">
+                        <rect key="frame" x="20" y="20" width="467" height="96"/>
+                        <autoresizingMask key="autoresizingMask" flexibleMaxX="YES" flexibleMinY="YES"/>
+                    </customView>
                 </subviews>
                 <constraints>
-                    <constraint firstAttribute="centerX" secondItem="Hz6-mo-xeY" secondAttribute="centerX" id="OG3-1c-Sd0"/>
-                    <constraint firstAttribute="centerY" secondItem="Hz6-mo-xeY" secondAttribute="centerY" id="s6i-b7-llN"/>
+                    <constraint firstItem="lcd-Ip-jjR" firstAttribute="top" secondItem="fqc-IQ-ceJ" secondAttribute="bottom" constant="8" symbolic="YES" id="GTC-QI-4wc"/>
+                    <constraint firstItem="fqc-IQ-ceJ" firstAttribute="trailing" secondItem="lcd-Ip-jjR" secondAttribute="trailing" id="Pth-4c-GNR"/>
+                    <constraint firstAttribute="bottom" secondItem="lcd-Ip-jjR" secondAttribute="bottom" constant="20" symbolic="YES" id="VNk-bs-YOH"/>
+                    <constraint firstAttribute="trailing" secondItem="fqc-IQ-ceJ" secondAttribute="trailing" constant="20" symbolic="YES" id="fER-QH-XqN"/>
+                    <constraint firstItem="fqc-IQ-ceJ" firstAttribute="top" secondItem="gIp-Ho-8D9" secondAttribute="top" constant="20" symbolic="YES" id="kpD-MX-yOS"/>
+                    <constraint firstItem="fqc-IQ-ceJ" firstAttribute="leading" secondItem="gIp-Ho-8D9" secondAttribute="leading" constant="20" symbolic="YES" id="to2-nb-CUV"/>
+                    <constraint firstItem="fqc-IQ-ceJ" firstAttribute="leading" secondItem="lcd-Ip-jjR" secondAttribute="leading" id="xJa-Qd-Ytg"/>
+                    <constraint firstItem="lcd-Ip-jjR" firstAttribute="top" secondItem="gIp-Ho-8D9" secondAttribute="top" constant="124" id="xrY-1x-QCm"/>
                 </constraints>
             </view>
             <connections>
diff --git a/MathPad/MPExpressionView.h b/MathPad/MPExpressionView.h
new file mode 100644
index 0000000..364de6d
--- /dev/null
+++ b/MathPad/MPExpressionView.h
@@ -0,0 +1,18 @@
+//
+//  MPExpressionView.h
+//  MathPad
+//
+//  Created by Kim Wittenburg on 17.04.14.
+//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
+//
+
+#import <Cocoa/Cocoa.h>
+
+@class MPExpressionView, MPRange;
+
+@interface MPExpressionView : NSView
+
+@property (nonatomic, getter = isEditable) BOOL editable;
+@property (nonatomic, strong) MPRange *selection;
+
+@end
diff --git a/MathPad/MPExpressionView.m b/MathPad/MPExpressionView.m
new file mode 100644
index 0000000..4e709e7
--- /dev/null
+++ b/MathPad/MPExpressionView.m
@@ -0,0 +1,29 @@
+//
+//  MPExpressionView.m
+//  MathPad
+//
+//  Created by Kim Wittenburg on 17.04.14.
+//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
+//
+
+#import "MPExpressionView.h"
+
+@implementation MPExpressionView
+
+- (id)initWithFrame:(NSRect)frame
+{
+    self = [super initWithFrame:frame];
+    if (self) {
+        // Initialization code here.
+    }
+    return self;
+}
+
+- (void)drawRect:(NSRect)dirtyRect
+{
+    [super drawRect:dirtyRect];
+    
+    // Drawing code here.
+}
+
+@end