YES ---- CR(R) ---- R : left-linear, C : CR and CP-closing, and Cdup/R : SN R: if(true(),x,y) -> x if(false(),x,y) -> y -(s(x),s(y)) -> -(x,y) -(x,0()) -> x -(0(),x) -> 0() <(s(x),s(y)) -> <(x,y) <(0(),s(x)) -> true() <(x,0()) -> false() mod(0(),y) -> 0() mod(x,s(y)) -> if(<(x,s(y)),x,mod(-(x,s(y)),s(y))) mod(x,0()) -> x gcd(x,y) -> gcd(y,mod(x,y)) gcd(x,0()) -> x gcd(0(),x) -> x CP(R): 0() -> 0() 0() -> 0() 0() -> if(<(0(),s(___y353)),0(),mod(-(0(),s(___y353)),s(___y353))) 0() -> 0() if(<(0(),s(___y392)),0(),mod(-(0(),s(___y392)),s(___y392))) -> 0() 0() -> 0() gcd(0(),mod(___y487,0())) -> ___y487 gcd(___y491,mod(0(),___y491)) -> ___y491 ___y520 -> gcd(0(),mod(___y520,0())) 0() -> 0() ___y554 -> gcd(___y554,mod(0(),___y554)) 0() -> 0() critical-pair-closing system C: if(true(),x,y) -> x if(false(),x,y) -> y -(s(x),s(y)) -> -(x,y) -(x,0()) -> x -(0(),x) -> 0() <(s(x),s(y)) -> <(x,y) <(0(),s(x)) -> true() <(x,0()) -> false() mod(0(),y) -> 0() mod(x,0()) -> x gcd(x,0()) -> x gcd(0(),x) -> x CR(C): see below. ---- CR(R) ---- R : left-linear, C : CR and CP-closing, and Cdup/R : SN R: if(true(),x,y) -> x if(false(),x,y) -> y -(s(x),s(y)) -> -(x,y) -(x,0()) -> x -(0(),x) -> 0() <(s(x),s(y)) -> <(x,y) <(0(),s(x)) -> true() <(x,0()) -> false() mod(0(),y) -> 0() mod(x,0()) -> x gcd(x,0()) -> x gcd(0(),x) -> x CP(R): 0() -> 0() 0() -> 0() 0() -> 0() 0() -> 0() 0() -> 0() 0() -> 0() critical-pair-closing system C: CR(C): see below. ---- CR(R) ---- R is empty.