FPA: Added .NET API calls

Signed-off-by: Christoph M. Wintersteiger <cwinter@microsoft.com>

src/api/dotnet/FPExpr.cs

@@ -0,0 +1,46 @@
+/*++
+Copyright (c) 2013 Microsoft Corporation
+
+Module Name:
+
+    FPExpr.cs
+
+Abstract:
+
+    Z3 Managed API: Floating Point Expressions
+
+Author:
+
+    Christoph Wintersteiger (cwinter) 2013-06-10
+
+Notes:
+    
+--*/
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+using System.Diagnostics.Contracts;
+
+namespace Microsoft.Z3
+{
+    /// <summary>
+    /// Floating Point Expressions
+    /// </summary>
+    public class FPExpr : Expr
+    {
+        #region Internal        
+        internal protected FPExpr(Context ctx)
+            : base(ctx)
+        {
+            Contract.Requires(ctx != null);
+        }
+        internal FPExpr(Context ctx, IntPtr obj)
+            : base(ctx, obj)
+        {
+            Contract.Requires(ctx != null);
+        }
+        #endregion
+    }
+}