YES ---- CR(R) ---- R : left-linear, C : CR and CP-closing, and Cdup/R : SN R: f(x) -> x f(x) -> f(f(x)) CP(R): ___y3 -> f(f(___y3)) f(f(___y5)) -> ___y5 critical-pair-closing system C: f(x) -> x CR(C): see below. ---- CR(R) ---- R : linear and strongly closed [Huet, 1980] R: f(x) -> x CP(R):