Righto, love: A whole lot of deducting going on www.tucsoncitizen.com ® : Righto, love: A whole lot of deducting going on CHUCK GRAHAM Published: 12.06.2007 What will it be? Revenge or forgiveness? Seeking revenge surely makes for better theater. Check out the mind games in "The Business of Murder" by Richard Harris. This ingenious whodunit shifts into a howdunit before reaching its resolution as a whydunit. Invisible Theatre has turned to secular counter-programming for the holidays by coming up with this crisp production directed by James Blair. The subject is murder, but the active ingredient is cleverness. If you love to watch a good mystery unfold onstage, if you enjoy staying at least one jump ahead of the playwright, this show is for you. It is written in the grand old tradition of Agatha Christie, with a whole lot of deducting going on. The story takes place in London, in the relatively modern time of 1981. The one-room set does include a telly that is turned on now a