matt grime
Science Advisor
Homework Helper
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Here is some stuff for you then:
as collection is not a set if given any cardinal A, there is a subset of cardinality greater than A.
this is why there is no set of all sets in ZF - if there were it would contain a set of card A for any A, but then it must contain P(A) which has card strictly greater than A. or if you like there is no maximal cardinal. you should probably look up weakly/strongly unreachable cardinals.
as it is what you appear to be axiomatizing is that the class of all things is called a 'set' because you aren't going to require it to satisfy any pesky things like the other axioms. (defining P(X) for all X but the universal set.
as collection is not a set if given any cardinal A, there is a subset of cardinality greater than A.
this is why there is no set of all sets in ZF - if there were it would contain a set of card A for any A, but then it must contain P(A) which has card strictly greater than A. or if you like there is no maximal cardinal. you should probably look up weakly/strongly unreachable cardinals.
as it is what you appear to be axiomatizing is that the class of all things is called a 'set' because you aren't going to require it to satisfy any pesky things like the other axioms. (defining P(X) for all X but the universal set.