Yes, that is a valid example."Illustrating A in B and B in C not Implies A in C

[mattmns]

Give an example to show that $$A\in B$$ and $$B \in C$$ does not imply that $$A \in C$$

Maybe I am misunderstanding the problem, but it seems as though there may be an infinite amount of solutions. For example: A = {1}, B = {2, {1}}, C = {5, {2, {1}}}

Is that correct?

 

[lightgrav]

Yes, they only wanted AN example.

You could try giving two of `em, or maybe a "rule".
How many different KINDS of rules can you come up with?