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problem 1312

hard sets

In each of the following, determine whether the statement is true or false. If it is true, prove it. If it is false, give an example. (i) If x \in A and A \subseteq B, then x \in B (ii) If A \subseteq B and B \subseteq C, then A \subseteq C (iii) If A \subseteq B and B \not\subseteq C, then A \not\subseteq C (iv) If A \subseteq B and B \not\subseteq C, then A \subseteq C (v) If x \in A and A \not\subseteq B, then x \in A (vi) If A \subseteq B and x \not\in B, then x \not\in A