premise: She slipped quietly into the bookshop , had a quick reconnoiter , and left without purchasing anything . 
hypothesis: She boldly marched into a bookstore and asked the salesclerk for a copy each of Hemingway 's The Sun Come Up Again and Throw Away the Gun and Steinbeck 's The Angry Grape . Is there a term for the errors that creep in while translating a passage back into the original tongue ?