Assignment:
Let Y be a subspace of X and let A be a subset of Y. Denote by (AX)- the closure of A in the topological space X and by (AY)- the closure of A in the topological space Y. Prove that (AY)- ⊂ (AX)-. Show that in general (AY)-≠(AX)- .
Provide complete and step by step solution for the question and show calculations and use formulas.