Let A1,A2 be standard operator algebras on complex Banach spaces X1, X2, respectively. For k ≥ 2, let (i1, . . . , im) be a sequence with terms chosen from {1, . . . , k}, and define the generalized Jordan product T1 ◦ · · · ◦ Tk = Ti1 · · ·Tim + Tim · · ·Ti1 on elements in Ai. This includes the usual Jordan product A1 ◦ A2 = A1A2 + A2A1, and the triple {A1, A2, A3} = A1A2A3 + A3A2A1. Assume th...