“…The fact that ϑ n,m = Id when 1 m, n 2 implies K n+1,m+1 = P m+n ; also, K n,2 ∼ = K 2,n is the multiplihedron J n for all n (see [14], [3], [10], [9]). The faces 24|13 and 1|24|3 of P 3,1 are degenerate in K 4,2 since ϑ 3,1 (24|13) = 24|1|3 and ϑ 3,1 (1|24|3) = 1|2|4|3; and dually, the faces 24|13 and 2|13|4 of P 1,3 are degenerate in KK 2,4 since ϑ 1,3 (24|13) = 2|4|13 and ϑ 1,3 (2|13|4) = 2|1|3|4.…”