Good job burr! You found out how to hide formulas. I tried the "display:none" but it didn't work alone.

I think we have to clarify something: we have a few things misclassified under "Logical Operators".

Here goes:

=,<,>, and ilk are "relational operators"; they "relate" two different numbers, whether they are the same or not, whichever is greater or less.

On the other hand, "and", "or", "xor", and "not" are true-blue "logical operators"; they take logical values as arguments.

I hope my explanation was clear enough.

It was definitely clear enough. You have to remember, though, that not everybody has your base of knowledge and experience with programming. Those things take time to develop and mature.

Heh, I've been talking about negation a lot recently. Anyway, this page says that negation is on the highest precedence level. However, this isn't true; it's clearly below level 2, since `-2 ^{2}=-4`.

I think we should put negation on the same level as exponentiation.

It's actually between priority levels 3 and 4 (as they currently stand). If it were on the same level as exponentiation, then -2^2 would be evaluated from left to right as (-2)^2, but you're quite right in pointing out that it doesn't work that way: it must be below level 3 in priority. On the other hand, -5 nCr 2 is treated as (-5) nCr 2 and causes a domain error, instead of being equal to -(5 nCr 2), so negation must be above priority level 4.

Thank you for pointing this out. I'll fix the article right away. (Note: the TI-83+ manual, page 47 where I took the information from, is remarkably unclear about this)

Mathematically, negation is simply multiplying by negative one. So -2^2 = -1*2^2 = -(2^2).

I realize they're equivalent mathematically, but that isn't how negation treated by the calculator. Take my example from earlier: -5 nCr 2 is different from -1*5 nCr 2. The latter is treated as -1*(5 nCr 2), and returns -10.