YES Proof: This system is confluent. By \cite{ALS94}, Theorem 4.1. This system is of type 3 or smaller. This system is strongly deterministic. All 2 critical pairs are joinable. x = y <= g(y) = s(x), g(g(y)) = x, g(x) = y, g(g(x)) = s(y): This critical pair is unfeasible. x = y <= g(y) = x, g(g(y)) = s(x), g(x) = s(y), g(g(x)) = y: This critical pair is unfeasible. By \cite{A14}, Theorem 11.5.9. This system is of type 3 or smaller. This system is deterministic. System R transformed to V(R) + Emb. Call external tool: ttt2 - trs 30 Input: f(x, y) -> x f(x, y) -> g(g(x)) f(x, y) -> g(x) f(x, y) -> y f(x, y) -> g(g(y)) f(x, y) -> g(y) g(x) -> x f(x, y) -> x f(x, y) -> y DP Processor: DPs: f#(x,y) -> g#(x) f#(x,y) -> g#(g(x)) f#(x,y) -> g#(y) f#(x,y) -> g#(g(y)) TRS: f(x,y) -> x f(x,y) -> g(g(x)) f(x,y) -> g(x) f(x,y) -> y f(x,y) -> g(g(y)) f(x,y) -> g(y) g(x) -> x TDG Processor: DPs: f#(x,y) -> g#(x) f#(x,y) -> g#(g(x)) f#(x,y) -> g#(y) f#(x,y) -> g#(g(y)) TRS: f(x,y) -> x f(x,y) -> g(g(x)) f(x,y) -> g(x) f(x,y) -> y f(x,y) -> g(g(y)) f(x,y) -> g(y) g(x) -> x graph: Qed