Added finite domain expressions and numerals to the .NET, Java, and Python APIs.

Relates to #318

src/api/dotnet/FiniteDomainExpr.cs

@@ -0,0 +1,38 @@
+/*++
+Copyright (<c>) 2012 Microsoft Corporation
+
+Module Name:
+
+    FiniteDomainExpr.cs
+
+Abstract:
+
+    Z3 Managed API: Finite-domain Expressions
+
+Author:
+
+    Christoph Wintersteiger (cwinter) 2015-12-02
+
+Notes:
+
+--*/
+using System;
+using System.Diagnostics.Contracts;
+
+namespace Microsoft.Z3
+{
+    /// <summary>
+    /// Finite-domain expressions
+    /// </summary>
+    public class FiniteDomainExpr : Expr
+    {
+        #region Internal
+        /// <summary> Constructor for DatatypeExpr </summary>
+        internal FiniteDomainExpr(Context ctx, IntPtr obj)
+            : base(ctx, obj)
+        {
+            Contract.Requires(ctx != null);
+        }
+        #endregion
+    }
+}