YES ---- CR(R) ---- R : left-linear, C : CR and CP-closing, and Cdup/R : SN R: h(c(),c()) -> h(b(),f(b())) f(h(a(),h(c(),a()))) -> c() h(c(),b()) -> f(a()) CP(R): critical-pair-closing system C: h(c(),c()) -> h(b(),f(b())) h(c(),b()) -> f(a()) CR(C): see below. ---- CR(R) ---- R : linear and strongly closed [Huet, 1980] R: h(c(),c()) -> h(b(),f(b())) h(c(),b()) -> f(a()) CP(R):