Morton (?),
I had discussion with Jon about this in the middle of last year when he visited my company. We were able to clarify a few of the issues related to using the angle units/dimensions and how the dimension of steradian is angle^2. He had access to my paper that you may have seen posted here.
The one thing Jon hasn't been able to do is add in user selectable cross checking to the trigonometric and hyperbolic functions such that the user can "demand" that Sine and Cosine must have inputs that are Angles. They are fully tolerant of Angle inputs but won't accept other dimensions. The inverse functions don't return Angles either, so the user needs to set that up themselves.
All in all a great start. All we need to do now is afford the licence fees! (My Mathcad user licences are much cheaper ;-).
Philip
