So. trade union = unison. People playing music as one are in unison. fair enough.
Please forgive my little dig. Nothing personal meant. I tend to have a little rant now and again.
No probs. Didn't take it as a dig, rather more a reminder, that if I want help with something, then I should supply the correct info first. It was my genuine mistake.
Trevor,
I'm afraid the equation means nothing to me. Mind you if it explains how to convert the contents of my dustbin into chateau neuf de plonk I might make a bit of an effort.