Korovkin sets in the space of continuous functions for operators of the class S m o

Test closures of sets in Banach spaces generated by linear functionals

“…One can fbrmulate similar problems for Korovkin sets. Among numerous publications containing solutions of Problem 1 for various E, X, Y, F, and (I), we mention [2,[7][8][9][10][11][12][13][14][15][16][17] (for Korovkin sets) and [8,9,[18][19][20][21] (Ibr test sets). These papers contain explicit conditions for the case of functionals.…”