apt-get behind a proxy

Why the hell I bumped suddenly into a proxy error each time I wanted to use aptitude?
I still wonder.
So your stuff helped me get through the issue.
Mine was a bit different though. I wanted to eliminate the proxy stuff.
So instead of the Acquire you proposed, I used the one you wanted to eliminate.
I did the same with the export http_proxy by replacing the proxy chain by false like this:
http_proxy=false
And all work fine so far.
Just as a curiosity, I would like to read an example with a real proxy in the text above. This would greatly help.
Many thanks,
jb