A specialization of written work and book generic. Each instance of book is an abstract work intended to be instantiated as a book of some sort. Instances of book may be intended to be instantiated in any book format: hardcopy (see book), electronic, audio tape, etc. Instances of book are usually also instances of textual pcw, but some may be comprised of mainly non-propositional information, such as images. Note that books with no propositional information (such as certain coloring books) would not be instances of this specialization of book generic.