User talk:Leduyquang753

Welcome! Just type anything you want to say as long as it meets the rules. Lê Duy Quang (Make some words | Contributions) 01:05, 24 June 2018 (UTC)

Symbols for the division operation
Hi. I was planning to talk to you about the division operators and other math notations you used on Tutorials/Enchantment mechanics. Before I could get to it, I saw your last edit with the summary "so that everyone won't debate about whether to use : or / for division", and a little while ago I saw your topic on the Community Portal talk page. Those answered a lot of my questions.

Apparently, Vietnam uses the "decimal comma" convention. I was aware that the "," and "." symbols were reversed (relative to the U.S.) in some countries, but I'd never seen ":" used for the division operator. I don't think the British use it that way either, even though some U.K. countries use the decimal comma. Do you know of any other countries besides Vietnam that use ":"?

Also, in your last edit you returned to using ';' (semicolon) as the separator in. That's probably motivated by the decimal-comma convention too, although it's not actually part of it. In the U.S. (and on the wiki), commas are always used as separators in math. (There are exceptions in certain high-level math disciplines, but we wouldn't be using those on this wiki.)

I also wanted to point out that we traded edits over one bit for which we were both using the wrong notation. It's in Step Three, where you originally wrote "the segement [0; T]", which I changed to "the interval [0, T]", which you then changed again to "the half range [0; T)". All of those edits were wrong, because the text is describing how to choose a random integer. The square bracket notation is only used with real numbers, because it doesn't make sense with integers. For example,  (which is termed a "half-open interval", by the way) denotes all values n such that 0 ≤ n < T. But in the integer domain, the largest value less than T is T−1, so   would denote the same set of values. But there's no real advantage to using the bracket notation with integers, so integer ranges are usually denoted in English using one of the older conventions   or  . (A lot of our readers wouldn't have any idea how to interpret the bracket notation, anyway. We learn it in high school, but most people never use it after they finish school and they forget they ever knew it.)

In answer to your question on the Community Portal, I think there's a way to get CSS to change it in your browser, but the wikitext would have to mark it somehow (probably with a class). Typically, that would mean using a template to generate the necessary marker. But most editors wouldn't see the point of doing that, since they don't know your preferred notation even exists, so it would be hard to get them to comply. In other words, you'd probably have to do most of the wikitext editing yourself, and keep it updated when people take out the template calls because they don't know why they're needed. I'm sorry you find it challenging to interpret the English-based notation we use, but unfortunately I don't think there's a good solution for you.

– Auldrick (talk &middot; contribs) 07:29, 24 October 2018 (UTC)


 * OK, I will talk about this in a more detailed way.


 * First, about the math notation, actually there isn't only one way of notating it in Vietnam. In education, primary school students use a cross (×) for multiplication, and when they go up to the secondary school, they are taught to denote it by a dot (.); and in any level, they use a space for digit grouping. However, people that are not students use a dot to group the digit instead (!). Even the currency of Vietnam use dots to group the digits for the value of money, e.g. 200.000 (two hundred thousand dong). So even in Vietnam itself this has already been pretty confusing, and after reading this you can understand why I can't adapt to a third, or even fourth, way of notation.


 * Actually, I do code, and every programming language uses the US' format, because why not, and I usually mess up typing real numbers. For instance, there was one time I typed the coordinates for a triangle, which was supposed to be, however because I am used to Vietnamese's kinda thing, I typed  . The consequence was I wasted 20 minutes figuring out what caused the triangle to be a weird shape. Luckily, most of the time I work with integers, so that hasn't become a big problem.


 * And for the intervals, I actually thought very carefully of it before entering. You can see my original phrase: "a random integer in the segment [0; T]". I later changed it to "[0; T)" because I was wrong. And both two are correct because although [0; T) is a set of any real number a that satisfies 0 ≤ a < T, but the word integer eliminates all the numbers that contain a meaningful decimal part. And why did I use segment and half range? In Vietnamese, [a; b] is called as "đoạn" which means "segment", [a; b) is "nửa khoảng" means "half range". I basically translated those to English. And I looked up Wikipedia, the page doesn't have any terminology for interval types, calling [a; b] as "closed interval" and [a; b) as "left-closed, right-open interval".


 * For evidence, here is a page in the textbook "Algebra 10" in Vietnam that defines types of intervals:


 * [[File:Math interval types.PNG]]


 * "II - FREQUENTLY USED SUBSETS OF R


 * In mathematics we usually meet these subsets of the set of real numbers R.


 * Range


 * (a; b) = {x ∈ R | a < x < b}


 * (a; +∞) = {x ∈ R | a < x}


 * (-∞; b) = {x ∈ R | x < b}.


 * Segment


 * [a; b] = {x ∈ R | a ≤ x ≤ b}.


 * Half range


 * [a; b) = {x ∈ R | a ≤ x < b}


 * (a; b] = {x ∈ R | a < x ≤ b}


 * [a; +∞) = {x ∈ R | a ≤ x}


 * (-∞; b] = {x ∈ R | x ≤ b}.


 * The symbol +∞ is read infinitely positive, the symbol -∞ is read infinitely negative."


 * So I hope this answers many of your questions.


 * Lê Duy Quang (Make some words | Contributions) 12:44, 24 October 2018 (UTC)