Question:
Finding the interior and the closure of a set
Easy: Consider the set A = {x∈ℜ2 : x1 = 0 or x2 = 0}. Compute,for the euclidean metric,the interior and the closure of A in ℜ2. If you consider A as a subspace,is it complete?
Hard: Consider the st A = {(xm)∈l∞ : one and only one component is different from 0}. Compute,for the metric d∞,the interior and the closure of A in l∞, If you consider A as a subspace,is it complete?