YES (VAR x y) (RULES f(x,f(y,a)) -> f(f(f(f(a,a),y),h(a)),x) ) The TRS is an overlay system and all critical pairs are trivial, thus termination of innermost rewriting is equivalent to termination of rewriting. Proving termination of innermost rewriting for jwcime2: -> Dependency pairs: nF_f(x,f(y,a)) -> nF_f(f(f(f(a,a),y),h(a)),x) nF_f(x,f(y,a)) -> nF_f(f(f(a,a),y),h(a)) nF_f(x,f(y,a)) -> nF_f(f(a,a),y) nF_f(x,f(y,a)) -> nF_f(a,a) -> Proof of termination for jwcime2_1: -> -> Dependency pairs in cycle: nF_f(x,f(y,a)) -> nF_f(f(f(f(a,a),y),h(a)),x) nF_f(x,f(y,a)) -> nF_f(f(a,a),y) UsableRules: f(x,f(y,a)) -> f(f(f(f(a,a),y),h(a)),x) Polynomial Interpretation: [f](X1,X2) = 2.X1.X2 + 2.X2 [a] = 2 [h](X) = 0 [nF_f](X1,X2) = 1/2.X1.X2 + 2.X2 TIME: 6.966e-3 -> -> Dependency pairs in cycle: nF_f(x,f(y,a)) -> nF_f(f(f(f(a,a),y),h(a)),x) UsableRules: f(x,f(y,a)) -> f(f(f(f(a,a),y),h(a)),x) Polynomial Interpretation: [f](X1,X2) = 2.X1.X2 + 2.X2 [a] = 2 [h](X) = 0 [nF_f](X1,X2) = 2.X1.X2 + 2.X2 TIME: 0.519477 SETTINGS: Base ordering: Polynomial ordering Proof mode: SCCs in DG + base ordering Upper bound for coeffs: 2 Rationals below 1 for all non-replacing args: No Polynomial interpretation: Simple mixed Coeffs in polynomials: All rationals Delta: automatic Termination was proved succesfully.