bruto
Penultimate Amazing
So what exactly do "we" use set theory for, if not to break something down with respect to its constituent parts?
In a single word, as usual, how about a nice big juicy red NO that's not what "we" use it for, because to do so would be a complete and utter misunderstanding of what sets are about. You have it backwards. Let me say this again, a different way: you have it backwards. Perhaps that wasn't clear, so I'll see if I can put it this way: You have it backwards. Sets and subsets are not about the consitutuent parts of an object if the object is in any way ordered. Sets are not ordered. They are not ordered. They really, truly, honest to golly-gee-gosh are not ordered. They are not ordered by definition. "NOT ORDERED" is a part of the sentence that defines what a set is. Think a moment about what this means. A set is not the assembly of constituent parts except in the most primitive sense that a set may made up of smaller pieces and smaller sets. But it is not ordered. It does not become something other than the set of those pieces when it becomes a set. Creating a newly defined object out of constituent parts is an act of ordering. A set of "soup and can" does not become a can of soup because a can of soup becomes the new definition of the set, and nothing but a can of soup can belong to that set. PUTTING CANS AND SOUP IN THE SAME SET DOES NOT PUT THE SOUP IN THE CAN! It does not in any way put the soup in any relation to the can, except insofar as the soup and the can have been named as members of a set. A set does not DO anything to the things it's made of. As soon as you name a set "can of soup" you disqualify from membership as either a member or a subset anything that is not AT LEAST a can of soup. A set is an unordered group of things which have common characteristics, defined by the definition of the set. It is a logical construct only. The parts of an assembly are not subsets of the assembly. When you speak of the component parts of something which is made from component parts you are not talking about sets and subsets. It is something else. It has been from the start.
In case you have not quite figured out what "unordered" means: if I take 50 blocks and throw them in a pile and decide to count them as a set, I have a set of 50 blocks. If I take the same set of 50 blocks and make a pyramid the set of blocks is the same. Same blocks, same set. Same set, same blocks. If I take the blocks and send one to each of the 50 states of the union, it's the same set. Same blocks, same set.
So, what are the subsets then, of "cans-of-soup?"
I keep telling you! The subsets of "cans-of-soup" are cans of soup. They can be nothing but cans of soup. They can be cans of soup distinguished by different characteristics that some cans of soup do not share with other cans of soup. Cans of Campbell's soup are a subset of all cans of soup, and cans of Progresso soup are another subset. They differ in some details, but they are ALL at least cans of soup. I think I've said this a number of times, but I'll say it again. To be a subset, a thing or a set must possess all of the properties that are defined by the set that includes it. All of them. All of them. Every single one. Not some. Not part. All of them. To be a subset of 'cans-of-soup" a thing must be AT LEAST a can of soup. It can be MORE than just a can of soup, but it cannot be LESS! Subsets become subsets by the ADDITION of characteristics, not the subtraction, a concept you seem to have had great diffiiculty comprehending.
Considering the fact that I haven't "formally" worked with set theory, I would have to give myself at least a B or a B+ here.
You have to be kidding. So far you have not only failed to undertstand any of it, but have displayed negative understanding: not only inability to grasp the idea, but inability to let go of wrong ideas that are incompatible with the idea. You have obstinately failed to comprehend the most elementary and basic concepts that would be covered in the first couple of pages of any junior high school lesson on sets. This is very easy stuff to understand, Iacchus, and if you cannot understand this little bit of elementary set theory, it seems quite likely that you misunderstand much else (to put it politely).
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