- #1
vrble
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1. Suppose that A is a subset of the power set of A. Prove that the power set of A is a subset of the power set of the power set of A.
Note: I'm going to use P(A) to mean the power set of A and P(P(A)) to mean the power set of the power set of A.
2. None
3. Let X be an arbitrary set and y an arbitrary element of that set. Suppose that X is an element of P(A) and A is a subset of P(A). It then follows by the definition of power sets that X is a subset of A and thus y is an element of A as well as P(A). We are also able to conclude, because y is an element of X and is arbitrary, that X is a subset of P(A) as well. This result shows that X is an element of P(A) as well as the P(P(A)). Therefore, if A is a subset of P(A), then P(A) is a subset of P(P(A)).
I apologize if my wording is unclear. I'm not entirely sure of the correctness of all of the aspects of my proof, and the line "We are also able to conclude, because y is an element of X and is arbitrary, that X is a subset of P(A) as well. " bothers me in particular. Am I able to make this kind of deduction?
Note: I'm going to use P(A) to mean the power set of A and P(P(A)) to mean the power set of the power set of A.
2. None
3. Let X be an arbitrary set and y an arbitrary element of that set. Suppose that X is an element of P(A) and A is a subset of P(A). It then follows by the definition of power sets that X is a subset of A and thus y is an element of A as well as P(A). We are also able to conclude, because y is an element of X and is arbitrary, that X is a subset of P(A) as well. This result shows that X is an element of P(A) as well as the P(P(A)). Therefore, if A is a subset of P(A), then P(A) is a subset of P(P(A)).
I apologize if my wording is unclear. I'm not entirely sure of the correctness of all of the aspects of my proof, and the line "We are also able to conclude, because y is an element of X and is arbitrary, that X is a subset of P(A) as well. " bothers me in particular. Am I able to make this kind of deduction?