So we find that (8 + 7) ?? 3 + 10 = 15?? 3 + 10 = 5 + 10 = 15 and 15 2 8 + 7 ?? (3 + 10) = 15 ?? 13 = =1 13 13 However, the meaning we attach to symbolic knowledge depends on how it is understood ??? what concepts and other ideas we connect to the symbols.