Merge branch 'master' of https://github.com/Jam3/math-as-code

mattdesl · mattdesl · commit dadc06d3b220 · 2015-07-01T23:39:11.000-04:00
diff --git a/README.md b/README.md
@@ -19,7 +19,7 @@ For simplicity, many of the code examples here operate on floating point values
 # contents
 
 - [variable name conventions](#variable-name-conventions)
-- [equals `=` `≈` `≠` `=:`](#equals-symbols)
+- [equals `=` `≈` `≠` `:=`](#equals-symbols)
 - [dot & cross `∙` `×` `∘`](#dot--cross)
   - [scalar multiplication](#scalar-multiplication)
   - [vector multiplication](#vector-multiplication)
@@ -51,11 +51,12 @@ This will also be the format of this guide.
 
 ## equals symbols
 
-There are a number of symbols resembling the equals sign `=`. Here are three common examples:
+There are a number of symbols resembling the equals sign `=`. Here are a few common examples:
 
 - `=` is for equality (values are the same)
 - `≠` is for inequality (value are not the same)
 - `≈` is for approximately equal to (`π ≈ 3.14159`)
+- `:=` is for definition (A is defined as B)
 
 In JavaScript:
 
@@ -74,44 +75,39 @@ function almostEqual(a, b, epsilon) {
 }
 ```
 
-In mathematics, the `:=` `=:` and `=` symbols are used for *definition*. The following defines *x* to be another name for 2*kj*.
+You might see the `:=`, `=:` and `=` symbols being used for *definition*.
 
-![equals1](img/equals1.png)
+For example, the following defines *x* to be another name for 2*kj*.
 
-<!-- x = 2kj -->
+![equals1](http://latex.codecogs.com/svg.latex?x%20%3A%3D%202kj)
 
-In JavaScript, we might use `=` to *define* our variables and provide aliases. The above equation defines the following:
+<!-- x := 2kj -->
 
-```js
-var x = 2 * k * j
-```
+In JavaScript, we might use `var` to *define* our variables and provide aliases:
 
 ```js
-var k = x / (2 * j)
-```
-
-```js
-var j = x / (2 * k)
+var x = 2 * k * j
 ```
 
 However, this is mutable, and only takes a snapshot of the values at that time. Some languages have pre-processor `#define` statements, which are closer to a mathematical *define*. 
 
-A more accurate representation in JavaScript (ES6) might look a bit like this:
+A more accurate *define* in JavaScript (ES6) might look a bit like this:
 
 ```js
 const f = (k, j) => 2 * k * j
 ```
 
-<!--
+The following, on the other hand, represents equality:
 
-///// Need a code sample?
-///// Maybe better suited in another place?
+![equals2](http://latex.codecogs.com/svg.latex?x%20%3D%202kj)
 
-The `≅` symbol is for [*congruence*](https://en.wikipedia.org/wiki/Congruence_%28geometry%29). For example, here the line segment AB is congruent with the segment CD.
+<!-- x = 2kj -->
 
-![equals2](img/equals2.png)
+The above equation might be interpreted in code as an [assertion](https://developer.mozilla.org/en-US/docs/Web/API/console/assert):
 
- \bar{AB} \cong \bar{CD} -->
+```js
+console.assert(x === (2 * k * j))
+```
 
 ## dot & cross
 
