YES Problem: q0(0(x1)) -> 0'(q1(x1)) q1(0(x1)) -> 0(q1(x1)) q1(1'(x1)) -> 1'(q1(x1)) 0(q1(1(x1))) -> q2(0(1'(x1))) 0'(q1(1(x1))) -> q2(0'(1'(x1))) 1'(q1(1(x1))) -> q2(1'(1'(x1))) 0(q2(0(x1))) -> q2(0(0(x1))) 0'(q2(0(x1))) -> q2(0'(0(x1))) 1'(q2(0(x1))) -> q2(1'(0(x1))) 0(q2(1'(x1))) -> q2(0(1'(x1))) 0'(q2(1'(x1))) -> q2(0'(1'(x1))) 1'(q2(1'(x1))) -> q2(1'(1'(x1))) q2(0'(x1)) -> 0'(q0(x1)) q0(1'(x1)) -> 1'(q3(x1)) q3(1'(x1)) -> 1'(q3(x1)) q3(b(x1)) -> b(q4(x1)) Proof: String Reversal Processor: 0(q0(x1)) -> q1(0'(x1)) 0(q1(x1)) -> q1(0(x1)) 1'(q1(x1)) -> q1(1'(x1)) 1(q1(0(x1))) -> 1'(0(q2(x1))) 1(q1(0'(x1))) -> 1'(0'(q2(x1))) 1(q1(1'(x1))) -> 1'(1'(q2(x1))) 0(q2(0(x1))) -> 0(0(q2(x1))) 0(q2(0'(x1))) -> 0(0'(q2(x1))) 0(q2(1'(x1))) -> 0(1'(q2(x1))) 1'(q2(0(x1))) -> 1'(0(q2(x1))) 1'(q2(0'(x1))) -> 1'(0'(q2(x1))) 1'(q2(1'(x1))) -> 1'(1'(q2(x1))) 0'(q2(x1)) -> q0(0'(x1)) 1'(q0(x1)) -> q3(1'(x1)) 1'(q3(x1)) -> q3(1'(x1)) b(q3(x1)) -> q4(b(x1)) KBO Processor: weight function: w0 = 1 w(q4) = w(b) = w(q3) = w(q2) = w(1) = w(1') = w(0') = w(q1) = w(q0) = w(0) = 1 precedence: b > q2 > q4 > 0' > q0 > 0 > 1 > 1' > q1 > q3 problem: Qed