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