[CentOS] two cents or not two cents

Les Mikesell wrote:
>   If you can treat something as a black box and trust it, the size of 
> the component isn't that important.
"If" or "IFF" ..(IF AND ONLY IF)..?  A deep scepticism forces me to  
treat all boxes as grey no matter how long since last visited... 
(including my own, which are a sort of dark grey!?).

Sean