An Unkindness of Ravens Fink. When Wexford does a favour for his wife—to look into the disappearance of one of their neighbours' husbands—everything he finds seems to confirm his first inkling: that this is simply another case of a bored middle-aged man having run off with a younger woman. However, when Rodney Williams is found dead, and another local man is stabbed in his car, Wexford finds himself thrown into an investigation involving a militant feministic organisation known as "Arria", who have taken the raven as their symbol. An Unkindness of Ravens An Unkindness of Ravens is a novel by British crime-writer Ruth Rendell.
Collectively exhaustive events or not. For example, tossing a particular biscuit for a group of several dogs cannot be repeated, no matter which dog snaps it up. One example of an event that is both collectively exhaustive and mutually exclusive is tossing a coin. The outcome must be either heads or tails, or p (heads or tails) = 1, so the outcomes are collectively exhaustive. When heads occurs, tails can't occur, or p (heads and tails) = 0, so the outcomes are also mutually exclusive. The term "exhaustive" has been used in the literature since at least 1914. Here are a few examples: