bug#9875: 24.0.90; Confusing description of the "window tree" in ELisp manual

[Drew Adams]

> The only problem with these diagrams is that ASCII art
> doesn't distinguish between internal and live windows:
>           ______________________________________
>          | ______  ____________________________ |
>          ||      || __________________________ ||
>          ||      ||| ___________  ___________ |||
>          ||      ||||           ||           ||||
>          ||      ||||           ||           ||||
>          ||      ||||_____W6____||_____W7____||||
>          ||      |||____________W4____________|||
>          ||      || __________________________ ||
>          ||      |||                          |||
>          ||      |||____________W5____________|||
>          ||__W2__||_____________W3_____________ |
>          |__________________W1__________________|
> 
> It would help to draw live and internal windows with 
> different lines, e.g.
> 
>           ______________________________________
>          |******** ____________________________ |
>          |*      *| __________________________ ||
>          |*      *||**************************|||
>          |*      *||*           **           *|||
>          |*      *||*           **           *|||
>          |*      *||******W6***********W7*****|||
>          |*      *||____________W4____________|||
>          |*      *|****************************||
>          |*      *|*                          *||
>          |*      *|*************W5*************||
>          |***W2***|_____________W3_____________ |
>          |__________________W1__________________|
> 
> but this is ugly and I can't find a better way to draw them.

Just use a different label/name convention: IW3 (or I3 or N3 or ...) for
internal windows.  (Mention the convention in the text, of course.)