YES (VAR x0 x1 y z x) (RULES g(x0,x1) -> f(x0,+(x0,-(x1)),x1) -(+(x1,x0)) -> +(-(x0),-(x1)) +(-(x0),+(x0,x1)) -> x1 +(-(x0),x0) -> 0() -(0()) -> 0() +(x0,0()) -> x0 -(-(x0)) -> x0 +(0(),x0) -> x0 +(x1,+(-(x1),x0)) -> x0 f(0(),y,z) -> y +(x,-(x)) -> 0() +(+(x,y),z) -> +(x,+(y,z)) ) (COMMENT Termination is shown by LPO with precedence: g > f > - > + > 0 )