YES We show the termination of the TRS R: half(|0|()) -> |0|() half(s(s(x))) -> s(half(x)) log(s(|0|())) -> |0|() log(s(s(x))) -> s(log(s(half(x)))) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: half#(s(s(x))) -> half#(x) p2: log#(s(s(x))) -> log#(s(half(x))) p3: log#(s(s(x))) -> half#(x) and R consists of: r1: half(|0|()) -> |0|() r2: half(s(s(x))) -> s(half(x)) r3: log(s(|0|())) -> |0|() r4: log(s(s(x))) -> s(log(s(half(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: log#(s(s(x))) -> log#(s(half(x))) and R consists of: r1: half(|0|()) -> |0|() r2: half(s(s(x))) -> s(half(x)) r3: log(s(|0|())) -> |0|() r4: log(s(s(x))) -> s(log(s(half(x)))) The set of usable rules consists of r1, r2, r3 Take the reduction pair: generalized weighted path order (>=MG, >MG) base order 1: max/plus interpretation on natural numbers: log#_A(x1) = max{12, x1 + 1} s_A(x1) = max{15, x1 + 11} half_A(x1) = max{6, x1 - 8} |0|_A = 5 log_A(x1) = max{10, x1 - 29} base order 2: precedence: log# = s = log > half > |0| partial status: pi(log#) = [1] pi(s) = [1] pi(half) = [] pi(|0|) = [] pi(log) = [] The following rules are removed: p1 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(s(x))) -> s(half(x)) r3: log(s(|0|())) -> |0|() r4: log(s(s(x))) -> s(log(s(half(x)))) The set of usable rules consists of r3 Take the reduction pair: generalized weighted path order (>=MG, >MG) base order 1: max/plus interpretation on natural numbers: half#_A(x1) = max{1, x1 - 1} s_A(x1) = x1 + 5 log_A(x1) = max{4, x1 - 22} |0|_A = 1 base order 2: precedence: half# = s > log > |0| partial status: pi(half#) = [] pi(s) = [1] pi(log) = [] pi(|0|) = [] The following rules are removed: p1 Then no dependency pair remains.