This is a used book that has been purchased and cut with a paper cutter. There are some stains and scratches. Although it's a thick book, the advantages of being cut are that it can be "carried in smaller portions" and "copied." You can copy the problem sections and write in them, or you can carry them in smaller portions by chapter, making it less of a burden because they are lighter. The spine of the book has been cut, but as far as I can see, there is almost no text loss, and I think it can be read without any problems.