YES Problem: f(x,y,z) -> g(<=(x,y),x,y,z) g(true(),x,y,z) -> z g(false(),x,y,z) -> f(f(p(x),y,z),f(p(y),z,x),f(p(z),x,y)) p(0()) -> 0() p(s(x)) -> x Proof: DP Processor: DPs: f#(x,y,z) -> g#(<=(x,y),x,y,z) g#(false(),x,y,z) -> p#(z) g#(false(),x,y,z) -> f#(p(z),x,y) g#(false(),x,y,z) -> p#(y) g#(false(),x,y,z) -> f#(p(y),z,x) g#(false(),x,y,z) -> p#(x) g#(false(),x,y,z) -> f#(p(x),y,z) g#(false(),x,y,z) -> f#(f(p(x),y,z),f(p(y),z,x),f(p(z),x,y)) TRS: f(x,y,z) -> g(<=(x,y),x,y,z) g(true(),x,y,z) -> z g(false(),x,y,z) -> f(f(p(x),y,z),f(p(y),z,x),f(p(z),x,y)) p(0()) -> 0() p(s(x)) -> x Usable Rule Processor: DPs: f#(x,y,z) -> g#(<=(x,y),x,y,z) g#(false(),x,y,z) -> p#(z) g#(false(),x,y,z) -> f#(p(z),x,y) g#(false(),x,y,z) -> p#(y) g#(false(),x,y,z) -> f#(p(y),z,x) g#(false(),x,y,z) -> p#(x) g#(false(),x,y,z) -> f#(p(x),y,z) g#(false(),x,y,z) -> f#(f(p(x),y,z),f(p(y),z,x),f(p(z),x,y)) TRS: p(0()) -> 0() p(s(x)) -> x f(x,y,z) -> g(<=(x,y),x,y,z) Arctic Interpretation Processor: dimension: 1 usable rules: interpretation: [p#](x0) = 1, [g#](x0, x1, x2, x3) = x0 + 0, [f#](x0, x1, x2) = 1, [s](x0) = 2x0 + 4, [0] = 2, [p](x0) = 3x0 + 1, [false] = 4, [g](x0, x1, x2, x3) = 5x0 + 13x1 + 1x2 + x3 + 8, [<=](x0, x1) = 0, [f](x0, x1, x2) = x1 + 2x2 + 1 orientation: f#(x,y,z) = 1 >= 0 = g#(<=(x,y),x,y,z) g#(false(),x,y,z) = 4 >= 1 = p#(z) g#(false(),x,y,z) = 4 >= 1 = f#(p(z),x,y) g#(false(),x,y,z) = 4 >= 1 = p#(y) g#(false(),x,y,z) = 4 >= 1 = f#(p(y),z,x) g#(false(),x,y,z) = 4 >= 1 = p#(x) g#(false(),x,y,z) = 4 >= 1 = f#(p(x),y,z) g#(false(),x,y,z) = 4 >= 1 = f#(f(p(x),y,z),f(p(y),z,x),f(p(z),x,y)) p(0()) = 5 >= 2 = 0() p(s(x)) = 5x + 7 >= x = x f(x,y,z) = y + 2z + 1 >= 13x + 1y + z + 8 = g(<=(x,y),x,y,z) problem: DPs: TRS: p(0()) -> 0() p(s(x)) -> x f(x,y,z) -> g(<=(x,y),x,y,z) Qed