YES ---- CR(R) ---- R : left-linear, C : CR and CP-closing, and Cdup/R : SN R: f(g(x,a(),b())) -> x g(f(h(c(),d())),x,y) -> h(k1(x),k2(y)) k1(a()) -> c() k2(b()) -> d() f(h(k1(a()),k2(b()))) -> f(h(c(),d())) f(h(c(),k2(b()))) -> f(h(c(),d())) f(h(k1(a()),d())) -> f(h(c(),d())) CP(R): f(h(k1(a()),k2(b()))) -> f(h(c(),d())) f(h(c(),k2(b()))) -> f(h(c(),d())) f(h(c(),d())) -> f(h(c(),d())) f(h(k1(a()),d())) -> f(h(c(),d())) f(h(c(),d())) -> f(h(c(),d())) critical-pair-closing system C: k1(a()) -> c() k2(b()) -> d() CR(C): see below. ---- CR(R) ---- R : left-linear, C : CR and CP-closing, and Cdup/R : SN R: k1(a()) -> c() k2(b()) -> d() CP(R): critical-pair-closing system C: CR(C): see below. ---- CR(R) ---- R is empty.