YES Problem: a(a(b(b(b(b(a(a(x1)))))))) -> a(a(c(c(a(a(b(b(x1)))))))) a(a(c(c(x1)))) -> c(c(c(c(a(a(x1)))))) c(c(c(c(c(c(x1)))))) -> b(b(c(c(b(b(x1)))))) Proof: String Reversal Processor: a(a(b(b(b(b(a(a(x1)))))))) -> b(b(a(a(c(c(a(a(x1)))))))) c(c(a(a(x1)))) -> a(a(c(c(c(c(x1)))))) c(c(c(c(c(c(x1)))))) -> b(b(c(c(b(b(x1)))))) Matrix Interpretation Processor: dim=4 interpretation: [1 0 0 0] [0 0 0 0] [c](x0) = [0 0 1 0]x0 [0 0 0 0] , [1 0 0 0] [0 1 1 0] [b](x0) = [0 0 0 0]x0 [0 0 0 0] , [1 0 0 1] [0] [0 1 0 0] [0] [a](x0) = [1 0 0 0]x0 + [1] [0 1 0 0] [0] orientation: [2 2 0 2] [1] [1 1 0 1] [0] [1 1 0 1] [1] [1 1 0 1] [1] a(a(b(b(b(b(a(a(x1)))))))) = [1 1 0 1]x1 + [1] >= [0 0 0 0]x1 + [0] = b(b(a(a(c(c(a(a(x1)))))))) [1 1 0 1] [1] [0 0 0 0] [0] [1 1 0 1] [0] [1 0 0 0] [0] [0 0 0 0] [0] [0 0 0 0] [0] c(c(a(a(x1)))) = [1 0 0 1]x1 + [1] >= [1 0 0 0]x1 + [1] = a(a(c(c(c(c(x1)))))) [0 0 0 0] [0] [0 0 0 0] [0] [1 0 0 0] [1 0 0 0] [0 0 0 0] [0 0 0 0] c(c(c(c(c(c(x1)))))) = [0 0 1 0]x1 >= [0 0 0 0]x1 = b(b(c(c(b(b(x1)))))) [0 0 0 0] [0 0 0 0] problem: c(c(a(a(x1)))) -> a(a(c(c(c(c(x1)))))) c(c(c(c(c(c(x1)))))) -> b(b(c(c(b(b(x1)))))) String Reversal Processor: a(a(c(c(x1)))) -> c(c(c(c(a(a(x1)))))) c(c(c(c(c(c(x1)))))) -> b(b(c(c(b(b(x1)))))) Bounds Processor: bound: 1 enrichment: match automaton: final states: {8,1} transitions: f30() -> 2* c0(10) -> 11* c0(5) -> 6* c0(7) -> 1* c0(4) -> 5* c0(11) -> 12* c0(6) -> 7* a0(2) -> 3* a0(3) -> 4* b0(12) -> 13* b0(2) -> 9* b0(9) -> 10* b0(13) -> 8* b1(40) -> 41* b1(35) -> 36* b1(15) -> 16* b1(67) -> 68* b1(47) -> 48* b1(42) -> 43* b1(64) -> 65* b1(39) -> 40* b1(19) -> 20* b1(14) -> 15* b1(46) -> 47* b1(36) -> 37* b1(68) -> 69* b1(63) -> 64* b1(43) -> 44* b1(18) -> 19* c1(65) -> 66* c1(45) -> 46* c1(37) -> 38* c1(17) -> 18* c1(44) -> 45* c1(66) -> 67* c1(16) -> 17* c1(38) -> 39* 1 -> 3,4 4 -> 63* 5 -> 42* 6 -> 14* 7 -> 35* 20 -> 1* 41 -> 5* 48 -> 7* 69 -> 6* problem: Qed