Radical excitement

Ok, I think I have the radical of the algebra in terms of the radical of the underlying ring. Hooray! A tiny step along the way but it might be as far as it's possible to go so I'm pleased, provided it's all correct of course and I don't wake up in the middle of the night realising I've made a mistake somewhere along the way....*fingers crossed*

Now just the invisible theorem and the tricky review to finish...