& Lesson 1: The World of the Turtle
& Ludus is a Logo: it leads with turtle graphics
& There are two panes on the right:
& * the turtle
& * the console

& You saw the console in Lesson 0: Hello World!

& `print!`ing things is very useful; remember you can do that.

& Now, we're going to give the turtle some functions.

forward! (100)

& let's dissect that

& forward! (100)
& ^^^^^^^^      `forward!` is is the name of the function
&          ^^^^ `100` is how far the turtle should walk
&          (...) notice that we have to put 100 in parens

& Uncomment the line below, and re-run the script:
& right! (0.25)

& right! (0.25)
& ^^^^^^        `right!` is the name of this function
&         ^^^^  0.25 is how far the turtle should turn
&        (....) notice again, we put the amount in parens
&               What is the unit of 0.25?

& Try out some other turtle functions. Here are a few:
& `left!`, `back!`, `penup!`, `pendown!`, `pencolor!`, `penwidth!`
& `home!`

& Note they all end with `!`. What happens if you forget the bang?
& There are abbreviations: `fd!`, `rt!`, `lt!`, `bk!`, etc.
& The turtle graphics functions (and abbreviations!) are listed at https://alea.ludus.dev/twc/ludus/src/branch/main/prelude.md#turtle-graphics