2017-09-12

    main = do putStrLn "Loaded"

Use “–” (two dashes) to comment to the end of the line. This is equivalent to Racket “;” (semicolon).
Function name rules:
- Must begin with lowercase letter.
- Hyphens (-) are not allowed in names.
- Underscore (_) may be used instead.
- Traditionally camelCase is used for functions. (First letter lowercase, then uppercase each new word.)
We will learn about the $ sign soon, but it is a substitute for putting parentheses from somewhere to the end of the line. That means
```
  putStrLn ( show ( grapher f 0 10 ) )
```
could be written as
```
  putStrLn $ show $ grapher f 0 10
```