Formal Knot Theory starts out with a planar diagram of a knot. Then the book shows how to label and name the intersections of the planar diagram. By the seventh page, you have an interesting group of terms and theorms. The author shows a method for converting the planar knot diagram into a Jordan curve with no crossing lines.
I am parked at Page 7 where the author introduces a Duality Conjecture. Here is where combinatorics and issues of Topology are introduced. A planar knot diagram has some very specific kinds of symmetry that can be observed using the labeling introduced. The symmetry and alternate ways of labeling a planar knot eventually develop into combinatorics and matrix statements.
The preparation required to work this book with ease is described as "advanced undergraduates and graduates".
I would ammend the "advanced undergraduate" qualification. This book has a reasonable price and very readable expansion of many knot ideas and problems. This is a good step beyond popular writing about math. This book is accessible and direct as distinguished from some other math books that are deliberately abstruse. Enough set and matrix math is modeled that I can follow along and consult other texts for examples and exersizes I need to work the examples.
Formal Knot Theory has the feel and pace of lecture material for a one semester course on Knots. For instance, I can't find in Formal Knot Theory a chapter heading associating knots with the Euler Polyhedron Theorm. But the Theorm is embedded in the ingenious labeling conventions introduced in the first chapter.