diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 00000000..412eeda7
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1,22 @@
+# Auto detect text files and perform LF normalization
+* text=auto
+
+# Custom for Visual Studio
+*.cs     diff=csharp
+*.sln    merge=union
+*.csproj merge=union
+*.vbproj merge=union
+*.fsproj merge=union
+*.dbproj merge=union
+
+# Standard to msysgit
+*.doc	 diff=astextplain
+*.DOC	 diff=astextplain
+*.docx diff=astextplain
+*.DOCX diff=astextplain
+*.dot  diff=astextplain
+*.DOT  diff=astextplain
+*.pdf  diff=astextplain
+*.PDF	 diff=astextplain
+*.rtf	 diff=astextplain
+*.RTF	 diff=astextplain
diff --git a/c#/Book/PetrolPump/PetrolPump/PetrolPump/PetrolPump.csproj b/c#/Book/PetrolPump/PetrolPump/PetrolPump/PetrolPump.csproj
index f2ba51a8..55f07527 100644
--- a/c#/Book/PetrolPump/PetrolPump/PetrolPump/PetrolPump.csproj
+++ b/c#/Book/PetrolPump/PetrolPump/PetrolPump/PetrolPump.csproj
@@ -70,6 +70,7 @@
     <Compile Include="Chapter3\Section8\Keypad.cs" />
     <Compile Include="Chapter3\Section8\KeypadPump.cs" />
     <Compile Include="Pump\Delivery.cs" />
+    <Compile Include="Pump\FillState.cs" />
     <Compile Include="Pump\Formatters.cs" />
     <Compile Include="Pump\Fuel.cs" />
     <Compile Include="Pump\Inputs.cs" />
diff --git a/c#/Book/PetrolPump/PetrolPump/PetrolPump/Pump/FillState.cs b/c#/Book/PetrolPump/PetrolPump/PetrolPump/Pump/FillState.cs
new file mode 100644
index 00000000..ba1f8d2d
--- /dev/null
+++ b/c#/Book/PetrolPump/PetrolPump/PetrolPump/Pump/FillState.cs
@@ -0,0 +1,28 @@
+namespace PetrolPump.Pump
+{
+  public class FillState 
+  {
+    public enum Type 
+    {
+        IDLE,
+        FILLING,
+        SALE_COMPLETE
+    }
+
+    public FillState(Type mode) 
+    {
+        this.Mode = mode;
+        this.Sale = null;
+    }
+
+    public FillState(Type mode, Sale sale) 
+    {
+        this.Mode = mode;
+        this.Sale = sale;
+    }
+
+    public readonly Type Mode;
+    public readonly Sale Sale;
+}
+
+}
diff --git a/c#/Sodium/Sodium.sln b/c#/Sodium/Sodium.sln
index 1a4f23a8..b405ec95 100644
--- a/c#/Sodium/Sodium.sln
+++ b/c#/Sodium/Sodium.sln
@@ -1,43 +1,43 @@
-
-Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 2012
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Sodium", "Sodium.csproj", "{D2080704-D359-4743-B568-5D976F9882A0}"
-EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Tests", "..\Tests\Tests.csproj", "{3BD22EFF-873C-48CF-B8E6-075ACA62F48C}"
-EndProject
-Global
-	GlobalSection(SolutionConfigurationPlatforms) = preSolution
-		Debug|Any CPU = Debug|Any CPU
-		Release|Any CPU = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(ProjectConfigurationPlatforms) = postSolution
-		{3BD22EFF-873C-48CF-B8E6-075ACA62F48C}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{3BD22EFF-873C-48CF-B8E6-075ACA62F48C}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{3BD22EFF-873C-48CF-B8E6-075ACA62F48C}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{3BD22EFF-873C-48CF-B8E6-075ACA62F48C}.Release|Any CPU.Build.0 = Release|Any CPU
-		{D2080704-D359-4743-B568-5D976F9882A0}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
-		{D2080704-D359-4743-B568-5D976F9882A0}.Debug|Any CPU.Build.0 = Debug|Any CPU
-		{D2080704-D359-4743-B568-5D976F9882A0}.Release|Any CPU.ActiveCfg = Release|Any CPU
-		{D2080704-D359-4743-B568-5D976F9882A0}.Release|Any CPU.Build.0 = Release|Any CPU
-	EndGlobalSection
-	GlobalSection(MonoDevelopProperties) = preSolution
-		StartupItem = Sodium.csproj
-		Policies = $0
-		$0.TextStylePolicy = $1
-		$1.FileWidth = 120
-		$1.TabWidth = 4
-		$1.IndentWidth = 2
-		$1.inheritsSet = Mono
-		$1.inheritsScope = text/plain
-		$1.scope = text/x-csharp
-		$0.CSharpFormattingPolicy = $2
-		$2.ElseIfNewLinePlacement = SameLine
-		$2.AfterDelegateDeclarationParameterComma = True
-		$2.inheritsSet = Mono
-		$2.inheritsScope = text/x-csharp
-		$2.scope = text/x-csharp
-	EndGlobalSection
-	GlobalSection(SolutionProperties) = preSolution
-		HideSolutionNode = FALSE
-	EndGlobalSection
-EndGlobal
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio 2012
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Sodium", "Sodium.csproj", "{D2080704-D359-4743-B568-5D976F9882A0}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Tests", "..\Tests\Tests.csproj", "{3BD22EFF-873C-48CF-B8E6-075ACA62F48C}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{3BD22EFF-873C-48CF-B8E6-075ACA62F48C}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{3BD22EFF-873C-48CF-B8E6-075ACA62F48C}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{3BD22EFF-873C-48CF-B8E6-075ACA62F48C}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{3BD22EFF-873C-48CF-B8E6-075ACA62F48C}.Release|Any CPU.Build.0 = Release|Any CPU
+		{D2080704-D359-4743-B568-5D976F9882A0}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D2080704-D359-4743-B568-5D976F9882A0}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D2080704-D359-4743-B568-5D976F9882A0}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D2080704-D359-4743-B568-5D976F9882A0}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(MonoDevelopProperties) = preSolution
+		StartupItem = Sodium.csproj
+		Policies = $0
+		$0.TextStylePolicy = $1
+		$1.FileWidth = 120
+		$1.TabWidth = 4
+		$1.IndentWidth = 2
+		$1.inheritsSet = Mono
+		$1.inheritsScope = text/plain
+		$1.scope = text/x-csharp
+		$0.CSharpFormattingPolicy = $2
+		$2.ElseIfNewLinePlacement = SameLine
+		$2.AfterDelegateDeclarationParameterComma = True
+		$2.inheritsSet = Mono
+		$2.inheritsScope = text/x-csharp
+		$2.scope = text/x-csharp
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+EndGlobal
diff --git a/c#/Sodium/src/Sodium/Extensions.cs b/c#/Sodium/src/Sodium/Extensions.cs
index 0ae83e71..c536c596 100644
--- a/c#/Sodium/src/Sodium/Extensions.cs
+++ b/c#/Sodium/src/Sodium/Extensions.cs
@@ -1,6 +1,7 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Xml.Schema;
 
 namespace Sodium
 {
@@ -65,6 +66,14 @@ public override bool Equals(object obj)
       return false;
     }
 
+    public override int GetHashCode()
+    {
+      var hash = IsPresent.GetHashCode();
+      if (value != null)
+        hash = (hash * 397) ^ value.GetHashCode();
+      return hash;
+    }
+
     public bool Equals(Optional<T> other)
     {
       if (IsPresent && other.IsPresent)
diff --git a/c#/Sodium/src/Sodium/PriorityQueue.cs b/c#/Sodium/src/Sodium/PriorityQueue.cs
index 696cd4d4..f073bd2f 100644
--- a/c#/Sodium/src/Sodium/PriorityQueue.cs
+++ b/c#/Sodium/src/Sodium/PriorityQueue.cs
@@ -162,7 +162,7 @@ private void TrickleDown(int index, HeapEntry<TA> he)
 
     public IEnumerator GetEnumerator()
     {
-      return new PriorityQueueEnumerator<TA>(this);
+      return new PriorityQueueEnumerator(this);
     }
     #endregion
 
@@ -202,7 +202,7 @@ void ISerializable.GetObjectData(SerializationInfo info, StreamingContext contex
 
     #region Priority Queue enumerator
     [Serializable]
-    private class PriorityQueueEnumerator<TA> : IEnumerator<TA> where TA : IComparable<TA>
+    private class PriorityQueueEnumerator : IEnumerator<TA> 
     {
       private int index;
       private PriorityQueue<TA> pq;