High Quality Content by WIKIPEDIA articles! Walls And Mirrors is an influential computer science textbook, for undergraduates taking a second computer science course (typically on the subject of data structures and algorithms), written by Paul Helman and Robert Veroff. The book has endured as a standard textbook through many editions because it strikes a balance between being too mathematically rigorous and formal — such as (for example) The Art of Computer Programming or MIT`s Introduction to Algorithms — and also being so informal, practical, and hands-on that computer science theory is not taught.