“…This is a generalization of 2-line queues used by Angel [Ang06] and the work of Ferrari, Fontes, and Kohayakawa [FFK94]. In [KMO15,KMO16b], the FM algorithm was reformulated in terms of the combinatorial R-matrix [NY97,Shi02] and using type A (1) n−1 Kirillov-Reshetikhin crystals [KKM + 92]. This interpretation gives a connection with five-vertex models, corner transfer matrices [Bax89], 3D integrable lattice models, and the tetrahedron equation [Zam80], yielding a matrix product formula for the steady state distribution different than [CdGW15,EFM09,PEM09].…”