The "positive" part is not the redundant part... it is the "nonzero" part that is. You have started with "every prime number is a natural number", which is a false premise... you can't rely on wikipedia for everything.

More precisely, that definition taken from wikipedia is closer to that for an irreducible, not a prime.

A nonzero element p in a ring is a prime if when p divides a product "ab", then p must divide one of the factors "a" or "b". A nonzero element p is irreducible if whenever you write p = st then either s or t must be a unit (in the case of integers, 1 or -1).

It just so happens that in the case of integers, the concepts of prime and irreducible turn out to be equivalent, which results in endless confusion. This means that "definition" of primes that people usually give is more correctly a "theorem". Anyhow, in the ring of integers, we have both positive *and* negative primes (i.e. 2 and -2 are both primes). In common speech though, we restrict ourselves to natural numbers (as the wikipedia article appears to do, sacrificing mathematical correctness for vulgarity).

So as I said to start with, the "positive" part isn't redundant; it's just being more precise than people normally bother to be. However yes, the "nonzero" part is redundant.

... was "Dive Into Python" (http://www.diveintopython.org/). I don't remember how I came across the book in the first place, but I did, I set and used the text for the course, and the publishers probably got some sales out of it, too, from those who like to have a bound copy for the bookcase. So perhaps you could have a look at that book's publisher for another alternative.

Name them all Bruce, just to avoid confusion.

Obviously! You are here on /.

Precisely! And I wish more multi-lingual sites would pay attention to my preferences as given in the accept-language header rather than demanding that I make my selection from their language menu.

...is Principles of Network and System Administration by Mark Burgess. Very enjoyable read, good for IT info and also good for the "people" side of sysadmin. After having read the book from beginning to end, I now find myself frequently going back to read bits and pieces.

Some point out that Word is already dominant in various parts of academia, like biology. Yes... on the desktop, but not for making the final print-ready copy in a quality journal. The publishers will transfer the content of the Word file to another system (e.g. InDesign, QuarkXPress, something in-house, or who knows, maybe even TeX) to produce the print copy. The point is that Word may be dominant on the desktop, but it isn't in the publishing house... and nor do I believe it ever will be because it's just not what it's made to do.

Documents created with programs like Word, while adequate in some situations, simply never look professional. Making a beautiful page is more complex than what word processors do. It concerns issues beyond merely identifying ligatures, like identifying aesthetically "optimal" positioning of characters, words and lines (kerning, line-breaking, etc.). Now apart from its utility in formatting equations, which is surely the reason for its ubiquity in mathematically oriented fields, what is ultimately special about TeX lies in such things as its line- and page-breaking algorithms (Have you ever noticed how changing one character can change a line-break ten lines earlier as TeX takes a holistic view of the page's aesthetics?).

Basically, comparing the publishing process to earlier times, word processors are the typewriters and typesetting systems like TeX are, well, the typesetters who skillfully place the type for the printing press. Making a newer, better typewriter is a great thing for the authors who use them, but it won't displace the typesetters. With a better typewriter, people might be more inclined to simply circulate their (comparatively ugly) typewriter copy, but serious publication will still demand typesetting.

As a final remark, several people have commented that TeX separates content from presentation. That is really quite far from the truth; if anything, I'd say this is really more true of word processors like Word (if used well)! Rather, that is where LaTeX comes in, defining lots of macros to essentially support this content / presentation separation.

Word is a word processor; TeX is a typesetting system.

- Most any of the books from the MAA, especially the New Mathematics Library (now Anneli Lax New Library?), e.g. Geometric Inequalities, Geometric Transformations, Graphs and Their Uses, An Introduction to Inequalities, Uses of Infinity, Continued Fractions, The Mathematics of Choice, etc. - Ian Stewart's books, especially Nature's Numbers. - Loren C. Larson's book, Problem Solving Through Problems. - Many of the smaller Dover books (e.g. Excursions in Geometry)