YES ---- CR(R) ---- R : left-linear, C : CR and CP-closing, and Cdup/R : SN R: a(a(b(b(x)))) -> b(b(b(b(b(a(a(a(a(a(x)))))))))) CP(R): critical-pair-closing system C: CR(C): see below. ---- CR(R) ---- R is empty.