[plt-scheme] Re: MrEd - Animated canvas

> Use the REPL (the command line) to see the difference:
>
> 1) Evaluate 'refresh' to see what it returns
> 2) Evaluate (refresh canvas_2) to see something completely different
> 3) Evaluate (lambda () (refresh canvas_2)) to see something like 1
> 4) Try (notify-callback (lambda () (refresh canvas_2)))
>
> rac

Thank you, i understand :)

Somebody knows why the bat flickers with a thread ?