Take the following as truth: Let us consider the dust-jacket blurbs of Cobuild, CED , and two other native-speaker  the British Longman Dictionary of the English Language (Longman , 1984) and the American Webster's Ninth New Collegiate Dictionary ( W9 , 1983).
Then the following statement: "There are no mistakes on the covers of any dictionaries, " is true, false, or inconclusive?
Answer: Inconclusive