YES Problem: minus(minus(x)) -> x minus(h(x)) -> h(minus(x)) minus(f(x,y)) -> f(minus(y),minus(x)) Proof: DP Processor: DPs: minus#(h(x)) -> minus#(x) minus#(f(x,y)) -> minus#(x) minus#(f(x,y)) -> minus#(y) TRS: minus(minus(x)) -> x minus(h(x)) -> h(minus(x)) minus(f(x,y)) -> f(minus(y),minus(x)) CDG Processor: DPs: minus#(h(x)) -> minus#(x) minus#(f(x,y)) -> minus#(x) minus#(f(x,y)) -> minus#(y) TRS: minus(minus(x)) -> x minus(h(x)) -> h(minus(x)) minus(f(x,y)) -> f(minus(y),minus(x)) graph: Qed