Lewis Carroll, well known as an author of books on the adventures of Alice, published quite a bit mathematical works, with some of that we want to acquaint our reader.Many his achievements in area of mathematical logic far passed the time. Ability of Carroll to decide so-called сориты (a "heap" drops litter in Greece) is the logical tasks presented by beaded of силлогизмов, at that conclusion one syllogism serves as a parcel other, - compared to the art. you will understand it, submerging in a book "Symbolic logic", in that a Carroll-mathematician offers more than hundred wonderful tasks.The second part of book includes a division the "Different differences", where logical paradoxes and letters are presented. Did Carroll attain the top of the work in two paradoxes: "What a tortoise said to Achilles"? and "Allen, Браун and Carr", baffling many and until now.Letters of Lewis Carroll to his large friends - children are the special, in truth unique genre, not having analogies and parallels. What only letters are not present in his enormous epistolary heritage: here and письма-ворчалки (if to take advantage of terminology of Винни-пуха), and письма-дразнилки, both letters-fairy-tales and mirror writing, written from an end to beginning, and, certainly, letter with mathematical letups.