Yes - these notes are definitely from 6.042. I TA'ed the class a couple of times as these notes were being developed. In my opinion, they are fantastic. Entertaining and engaging, while still maintaining an appropriate level of mathematical rigor.
It goes on to tell what ∀ means, and what N means, but excludes ∈.
This tells me there is a level of maths prerequisites required. For those of us who had liberal arts backgrounds with very little math who are programmers by sweat and knack, where can one go to get enough training to be ready to read something like this? I'd love to get through it and finally feel I'm on equal footing with some of my CS-trained peers (and actually be able to leverage the concepts at work) but seeing this early in the book leads me to believe I need some prerequisites first.
This is just a little set notation, ∈ means 'is an element of' the set after the symbol. So for example, ∀ n ∈ N n^2 + n + 41 means 'for every n in the set of real numbers, n^2+n+41'. Reading the linked story, that's a proposition for the definition of prime numbers setting up for a proof. You usually learn set notation, proofs, induction, relations, and most of the stuff before probability I scanned in the Table of Contents there in a discrete math course. Many also cover probability, but ymmv.
By the way I did have algebra 1 and 2, geometry, business calculus, and statistics, but it's been a looooooooooong time and at this point it's as if I didn't.
I feel I can now go back and cover all the math i've forgotten since the first couple CS years (only a couple years ago!). I'm not really sure if it is worth the time from a practical standpoint, however I always feel slightly slower than other students when it comes to algorithm-related classes.
This has nothing to do with the quality of the text, and I appreciate someone using not-computer-modern for a TeX-ed text, but the capital T's are just strange.
I have to say that my favourite book ever on Computer Science Mathematics is actually Applied Mathematics for Database Professionals, by APress. It gave me an extremely thorough understanding of logic, set theory, and disabused me of my incorrect notion that relational databases were because of ER diagrams :-)
