[zeroca]

Originally Posted by subversion

in the example you used of a bag full of green things I would say that the set is defined as the bag full of green things, in which case the bag is part of the contents. So even though the set is the bag that's only full of green things, the set includes the bag no matter what color it is. So for sake of descriptive labelling, you might want to make the bag green and that way you know what's in it. But regardless of what color the bag is it is always part of the set of the bag full of green things.

Sub, I haven’t dealt with higher mathematics for 30 years now. I recently consulted the site http://en.wikipedia.org/wiki/Russell%27s_paradox, skipped through some definitions of sets and then tried to offer my opinion of my leisure time about it. My explanations aren’t that of professional mathematician’s. If all this is as you say, it means, I interpreted everything incorrect way.