YES We show the termination of the TRS R: half(|0|()) -> |0|() half(s(|0|())) -> |0|() half(s(s(x))) -> s(half(x)) bits(|0|()) -> |0|() bits(s(x)) -> s(bits(half(s(x)))) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: half#(s(s(x))) -> half#(x) p2: bits#(s(x)) -> bits#(half(s(x))) p3: bits#(s(x)) -> half#(s(x)) and R consists of: r1: half(|0|()) -> |0|() r2: half(s(|0|())) -> |0|() r3: half(s(s(x))) -> s(half(x)) r4: bits(|0|()) -> |0|() r5: bits(s(x)) -> s(bits(half(s(x)))) The estimated dependency graph contains the following SCCs: {p2} {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: bits#(s(x)) -> bits#(half(s(x))) and R consists of: r1: half(|0|()) -> |0|() r2: half(s(|0|())) -> |0|() r3: half(s(s(x))) -> s(half(x)) r4: bits(|0|()) -> |0|() r5: bits(s(x)) -> s(bits(half(s(x)))) The set of usable rules consists of r1, r2, r3 Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: bits#_A(x1) = max{5, x1 + 3} s_A(x1) = x1 + 14 half_A(x1) = max{8, x1 - 5} |0|_A = 7 precedence: bits# = s > half = |0| partial status: pi(bits#) = [1] pi(s) = [] pi(half) = [] pi(|0|) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: half#(s(s(x))) -> half#(x) and R consists of: r1: half(|0|()) -> |0|() r2: half(s(|0|())) -> |0|() r3: half(s(s(x))) -> s(half(x)) r4: bits(|0|()) -> |0|() r5: bits(s(x)) -> s(bits(half(s(x)))) The set of usable rules consists of (no rules) Take the monotone reduction pair: weighted path order base order: max/plus interpretations on natural numbers: half#_A(x1) = x1 + 5 s_A(x1) = x1 + 2 precedence: half# = s partial status: pi(half#) = [1] pi(s) = [1] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.