YES Problem: a(b(c(a(x1)))) -> b(a(c(b(a(b(x1)))))) a(d(x1)) -> c(x1) a(f(f(x1))) -> g(x1) b(g(x1)) -> g(b(x1)) c(x1) -> f(f(x1)) c(a(c(x1))) -> b(c(a(b(c(x1))))) c(d(x1)) -> a(a(x1)) g(x1) -> c(a(x1)) g(x1) -> d(d(d(d(x1)))) Proof: Arctic Interpretation Processor: dimension: 1 interpretation: [g](x0) = 10x0, [f](x0) = 3x0, [d](x0) = 2x0, [b](x0) = x0, [c](x0) = 6x0, [a](x0) = 4x0 orientation: a(b(c(a(x1)))) = 14x1 >= 14x1 = b(a(c(b(a(b(x1)))))) a(d(x1)) = 6x1 >= 6x1 = c(x1) a(f(f(x1))) = 10x1 >= 10x1 = g(x1) b(g(x1)) = 10x1 >= 10x1 = g(b(x1)) c(x1) = 6x1 >= 6x1 = f(f(x1)) c(a(c(x1))) = 16x1 >= 16x1 = b(c(a(b(c(x1))))) c(d(x1)) = 8x1 >= 8x1 = a(a(x1)) g(x1) = 10x1 >= 10x1 = c(a(x1)) g(x1) = 10x1 >= 8x1 = d(d(d(d(x1)))) problem: a(b(c(a(x1)))) -> b(a(c(b(a(b(x1)))))) a(d(x1)) -> c(x1) a(f(f(x1))) -> g(x1) b(g(x1)) -> g(b(x1)) c(x1) -> f(f(x1)) c(a(c(x1))) -> b(c(a(b(c(x1))))) c(d(x1)) -> a(a(x1)) g(x1) -> c(a(x1)) Arctic Interpretation Processor: dimension: 1 interpretation: [g](x0) = x0, [f](x0) = x0, [d](x0) = 5x0, [b](x0) = x0, [c](x0) = x0, [a](x0) = x0 orientation: a(b(c(a(x1)))) = x1 >= x1 = b(a(c(b(a(b(x1)))))) a(d(x1)) = 5x1 >= x1 = c(x1) a(f(f(x1))) = x1 >= x1 = g(x1) b(g(x1)) = x1 >= x1 = g(b(x1)) c(x1) = x1 >= x1 = f(f(x1)) c(a(c(x1))) = x1 >= x1 = b(c(a(b(c(x1))))) c(d(x1)) = 5x1 >= x1 = a(a(x1)) g(x1) = x1 >= x1 = c(a(x1)) problem: a(b(c(a(x1)))) -> b(a(c(b(a(b(x1)))))) a(f(f(x1))) -> g(x1) b(g(x1)) -> g(b(x1)) c(x1) -> f(f(x1)) c(a(c(x1))) -> b(c(a(b(c(x1))))) g(x1) -> c(a(x1)) String Reversal Processor: a(c(b(a(x1)))) -> b(a(b(c(a(b(x1)))))) f(f(a(x1))) -> g(x1) g(b(x1)) -> b(g(x1)) c(x1) -> f(f(x1)) c(a(c(x1))) -> c(b(a(c(b(x1))))) g(x1) -> a(c(x1)) Matrix Interpretation Processor: dim=1 interpretation: [g](x0) = 4x0 + 8, [f](x0) = 2x0, [b](x0) = x0, [c](x0) = 4x0, [a](x0) = x0 + 4 orientation: a(c(b(a(x1)))) = 4x1 + 20 >= 4x1 + 20 = b(a(b(c(a(b(x1)))))) f(f(a(x1))) = 4x1 + 16 >= 4x1 + 8 = g(x1) g(b(x1)) = 4x1 + 8 >= 4x1 + 8 = b(g(x1)) c(x1) = 4x1 >= 4x1 = f(f(x1)) c(a(c(x1))) = 16x1 + 16 >= 16x1 + 16 = c(b(a(c(b(x1))))) g(x1) = 4x1 + 8 >= 4x1 + 4 = a(c(x1)) problem: a(c(b(a(x1)))) -> b(a(b(c(a(b(x1)))))) g(b(x1)) -> b(g(x1)) c(x1) -> f(f(x1)) c(a(c(x1))) -> c(b(a(c(b(x1))))) Arctic Interpretation Processor: dimension: 1 interpretation: [g](x0) = 3x0, [f](x0) = x0, [b](x0) = x0, [c](x0) = 2x0, [a](x0) = 6x0 orientation: a(c(b(a(x1)))) = 14x1 >= 14x1 = b(a(b(c(a(b(x1)))))) g(b(x1)) = 3x1 >= 3x1 = b(g(x1)) c(x1) = 2x1 >= x1 = f(f(x1)) c(a(c(x1))) = 10x1 >= 10x1 = c(b(a(c(b(x1))))) problem: a(c(b(a(x1)))) -> b(a(b(c(a(b(x1)))))) g(b(x1)) -> b(g(x1)) c(a(c(x1))) -> c(b(a(c(b(x1))))) String Reversal Processor: a(b(c(a(x1)))) -> b(a(c(b(a(b(x1)))))) b(g(x1)) -> g(b(x1)) c(a(c(x1))) -> b(c(a(b(c(x1))))) Bounds Processor: bound: 0 enrichment: match automaton: final states: {9,8,1} transitions: f60() -> 2* b0(10) -> 11* b0(7) -> 1* b0(2) -> 3* b0(4) -> 5* b0(13) -> 9* a0(11) -> 12* a0(6) -> 7* a0(3) -> 4* c0(5) -> 6* c0(12) -> 13* c0(2) -> 10* g0(3) -> 8* 1 -> 4,12 8 -> 3* 9 -> 10* problem: Qed