“…It is well known that the set of compact operators is the unique maximal ideal of when or [5]. In these cases, the set of compact operators coincides with the set There are many other Banach spaces X for which is the unique maximal ideal of , including [4], [3], , [13, 8, 10–12], [2], [16], [7] and an Orlicz sequence space which is close to [14].…”