e the -algebra of bounded, scalar-valued functions on G with the supremum norm and let . Now,let G be a topological group with identity e. A subset is said to be (i) an –interpolation set if every bounded function can be extended to a function uch that (ii) an approximable -interpolation set if it is an -interpolation set and for every neigh- bourhood of e, there are open neighbourhoods of e with uch that, for each there is with and Interpolation sets have been a key technique for the construction of functions o
