YES Problem: a(a(a(x1))) -> b(b(x1)) b(b(b(x1))) -> c(x1) c(x1) -> d(d(x1)) d(x1) -> a(a(x1)) Proof: Matrix Interpretation Processor: dim=1 interpretation: [b](x0) = x0 + 3, [d](x0) = x0 + 4, [a](x0) = x0 + 2, [c](x0) = x0 + 8 orientation: a(a(a(x1))) = x1 + 6 >= x1 + 6 = b(b(x1)) b(b(b(x1))) = x1 + 9 >= x1 + 8 = c(x1) c(x1) = x1 + 8 >= x1 + 8 = d(d(x1)) d(x1) = x1 + 4 >= x1 + 4 = a(a(x1)) problem: a(a(a(x1))) -> b(b(x1)) c(x1) -> d(d(x1)) d(x1) -> a(a(x1)) Bounds Processor: bound: 3 enrichment: match automaton: final states: {5} transitions: c0(5) -> 5* a1(20) -> 21* a1(19) -> 20* d0(5) -> 5* b3(112) -> 113* b3(78) -> 79* b3(111) -> 112* b3(71) -> 72* b3(91) -> 92* b3(79) -> 80* b3(72) -> 73* b3(90) -> 91* b2(23) -> 24* b2(45) -> 46* b2(95) -> 96* b2(22) -> 23* b2(93) -> 94* b2(44) -> 45* b0(5) -> 5* a0(5) -> 5* d1(13) -> 14* d1(12) -> 13* a2(67) -> 68* a2(66) -> 67* a2(60) -> 61* a2(59) -> 60* b1(103) -> 104* b1(85) -> 86* b1(10) -> 11* b1(9) -> 10* b1(86) -> 87* b1(37) -> 38* b1(30) -> 31* b1(31) -> 32* 94 -> 45* 19 -> 37,22 24 -> 67,20 92 -> 61,14 68 -> 13* 46 -> 68,13,59,21,5,12,9,19 113 -> 60* 104 -> 10* 12 -> 66* 14 -> 5* 66 -> 111* 11 -> 68,13,67,59,21,20,5 67 -> 90* 21 -> 5* 38 -> 10* 73 -> 68,13,59 60 -> 93,85,71 13 -> 59* 20 -> 44,30 59 -> 103,95,78 5 -> 19,12,9 96 -> 23* 80 -> 67* 87 -> 20,30,5,44,67 32 -> 67,5,12,9,19,20 61 -> 14,5 problem: Qed