The attached .pdf-format document describes a simple VisualAPL class.
Because this VisualAPL class has been exposed as ActiveX (COM), it can be used by APL+Win. The pdf shows how this is done.
In addition this class can also be used by any other Visual Studio 2008 project, including Windows Presentation Foundation (WPF), the latest C# Windows GUI creation technology. The pdf illustrates the WPF GUI and the calculation performed by the VisualAPL class.
The attached .zip-format file contains the complete Visual Studio 2008 solution including the VisualAPL project and the C# WPF project.