YES(?,O(n^1)) Problem: a(x1) -> g(d(x1)) b(b(b(x1))) -> c(d(c(x1))) b(b(x1)) -> a(g(g(x1))) c(d(x1)) -> g(g(x1)) g(g(g(x1))) -> b(b(x1)) Proof: RT Transformation Processor: strict: a(x1) -> g(d(x1)) b(b(b(x1))) -> c(d(c(x1))) b(b(x1)) -> a(g(g(x1))) c(d(x1)) -> g(g(x1)) g(g(g(x1))) -> b(b(x1)) weak: Matrix Interpretation Processor: dimension: 1 interpretation: [c](x0) = x0, [b](x0) = x0, [g](x0) = x0 + 13, [d](x0) = x0, [a](x0) = x0 + 2 orientation: a(x1) = x1 + 2 >= x1 + 13 = g(d(x1)) b(b(b(x1))) = x1 >= x1 = c(d(c(x1))) b(b(x1)) = x1 >= x1 + 28 = a(g(g(x1))) c(d(x1)) = x1 >= x1 + 26 = g(g(x1)) g(g(g(x1))) = x1 + 39 >= x1 = b(b(x1)) problem: strict: a(x1) -> g(d(x1)) b(b(b(x1))) -> c(d(c(x1))) b(b(x1)) -> a(g(g(x1))) c(d(x1)) -> g(g(x1)) weak: g(g(g(x1))) -> b(b(x1)) Matrix Interpretation Processor: dimension: 1 interpretation: [c](x0) = x0 + 16, [b](x0) = x0, [g](x0) = x0, [d](x0) = x0 + 11, [a](x0) = x0 orientation: a(x1) = x1 >= x1 + 11 = g(d(x1)) b(b(b(x1))) = x1 >= x1 + 43 = c(d(c(x1))) b(b(x1)) = x1 >= x1 = a(g(g(x1))) c(d(x1)) = x1 + 27 >= x1 = g(g(x1)) g(g(g(x1))) = x1 >= x1 = b(b(x1)) problem: strict: a(x1) -> g(d(x1)) b(b(b(x1))) -> c(d(c(x1))) b(b(x1)) -> a(g(g(x1))) weak: c(d(x1)) -> g(g(x1)) g(g(g(x1))) -> b(b(x1)) Matrix Interpretation Processor: dimension: 1 interpretation: [c](x0) = x0 + 17, [b](x0) = x0, [g](x0) = x0 + 9, [d](x0) = x0 + 1, [a](x0) = x0 + 12 orientation: a(x1) = x1 + 12 >= x1 + 10 = g(d(x1)) b(b(b(x1))) = x1 >= x1 + 35 = c(d(c(x1))) b(b(x1)) = x1 >= x1 + 30 = a(g(g(x1))) c(d(x1)) = x1 + 18 >= x1 + 18 = g(g(x1)) g(g(g(x1))) = x1 + 27 >= x1 = b(b(x1)) problem: strict: b(b(b(x1))) -> c(d(c(x1))) b(b(x1)) -> a(g(g(x1))) weak: a(x1) -> g(d(x1)) c(d(x1)) -> g(g(x1)) g(g(g(x1))) -> b(b(x1)) Matrix Interpretation Processor: dimension: 1 interpretation: [c](x0) = x0 + 4, [b](x0) = x0 + 3, [g](x0) = x0 + 2, [d](x0) = x0, [a](x0) = x0 + 2 orientation: b(b(b(x1))) = x1 + 9 >= x1 + 8 = c(d(c(x1))) b(b(x1)) = x1 + 6 >= x1 + 6 = a(g(g(x1))) a(x1) = x1 + 2 >= x1 + 2 = g(d(x1)) c(d(x1)) = x1 + 4 >= x1 + 4 = g(g(x1)) g(g(g(x1))) = x1 + 6 >= x1 + 6 = b(b(x1)) problem: strict: b(b(x1)) -> a(g(g(x1))) weak: b(b(b(x1))) -> c(d(c(x1))) a(x1) -> g(d(x1)) c(d(x1)) -> g(g(x1)) g(g(g(x1))) -> b(b(x1)) Arctic Interpretation Processor: dimension: 2 interpretation: [4 0 ] [c](x0) = [3 -&]x0, [0 4] [b](x0) = [1 3]x0, [0 3] [g](x0) = [0 2]x0, [0 1 ] [d](x0) = [-& -&]x0, [1 1] [a](x0) = [0 1]x0 orientation: [5 7] [4 6] b(b(x1)) = [4 6]x1 >= [3 5]x1 = a(g(g(x1))) [8 10] [8 4] b(b(b(x1))) = [7 9 ]x1 >= [7 3]x1 = c(d(c(x1))) [1 1] [0 1] a(x1) = [0 1]x1 >= [0 1]x1 = g(d(x1)) [4 5] [3 5] c(d(x1)) = [3 4]x1 >= [2 4]x1 = g(g(x1)) [5 7] [5 7] g(g(g(x1))) = [4 6]x1 >= [4 6]x1 = b(b(x1)) problem: strict: weak: b(b(x1)) -> a(g(g(x1))) b(b(b(x1))) -> c(d(c(x1))) a(x1) -> g(d(x1)) c(d(x1)) -> g(g(x1)) g(g(g(x1))) -> b(b(x1)) Qed