YES Problem: a(b(x1)) -> x1 a(c(x1)) -> c(b(c(c(x1)))) b(c(x1)) -> a(b(x1)) Proof: DP Processor: DPs: a#(c(x1)) -> b#(c(c(x1))) b#(c(x1)) -> b#(x1) b#(c(x1)) -> a#(b(x1)) TRS: a(b(x1)) -> x1 a(c(x1)) -> c(b(c(c(x1)))) b(c(x1)) -> a(b(x1)) TDG Processor: DPs: a#(c(x1)) -> b#(c(c(x1))) b#(c(x1)) -> b#(x1) b#(c(x1)) -> a#(b(x1)) TRS: a(b(x1)) -> x1 a(c(x1)) -> c(b(c(c(x1)))) b(c(x1)) -> a(b(x1)) graph: b#(c(x1)) -> b#(x1) -> b#(c(x1)) -> a#(b(x1)) b#(c(x1)) -> b#(x1) -> b#(c(x1)) -> b#(x1) b#(c(x1)) -> a#(b(x1)) -> a#(c(x1)) -> b#(c(c(x1))) a#(c(x1)) -> b#(c(c(x1))) -> b#(c(x1)) -> a#(b(x1)) a#(c(x1)) -> b#(c(c(x1))) -> b#(c(x1)) -> b#(x1) Arctic Interpretation Processor: dimension: 1 interpretation: [b#](x0) = -3x0 + 3, [a#](x0) = -1x0 + 0, [c](x0) = 1x0 + 5, [a](x0) = 1x0 + 0, [b](x0) = -1x0 + 3 orientation: a#(c(x1)) = x1 + 4 >= -1x1 + 3 = b#(c(c(x1))) b#(c(x1)) = -2x1 + 3 >= -3x1 + 3 = b#(x1) b#(c(x1)) = -2x1 + 3 >= -2x1 + 2 = a#(b(x1)) a(b(x1)) = x1 + 4 >= x1 = x1 a(c(x1)) = 2x1 + 6 >= 2x1 + 6 = c(b(c(c(x1)))) b(c(x1)) = x1 + 4 >= x1 + 4 = a(b(x1)) problem: DPs: b#(c(x1)) -> b#(x1) b#(c(x1)) -> a#(b(x1)) TRS: a(b(x1)) -> x1 a(c(x1)) -> c(b(c(c(x1)))) b(c(x1)) -> a(b(x1)) EDG Processor: DPs: b#(c(x1)) -> b#(x1) b#(c(x1)) -> a#(b(x1)) TRS: a(b(x1)) -> x1 a(c(x1)) -> c(b(c(c(x1)))) b(c(x1)) -> a(b(x1)) graph: b#(c(x1)) -> b#(x1) -> b#(c(x1)) -> b#(x1) b#(c(x1)) -> b#(x1) -> b#(c(x1)) -> a#(b(x1)) CDG Processor: DPs: b#(c(x1)) -> b#(x1) b#(c(x1)) -> a#(b(x1)) TRS: a(b(x1)) -> x1 a(c(x1)) -> c(b(c(c(x1)))) b(c(x1)) -> a(b(x1)) graph: Qed