YES We show the termination of the TRS R: max(L(x)) -> x max(N(L(|0|()),L(y))) -> y max(N(L(s(x)),L(s(y)))) -> s(max(N(L(x),L(y)))) max(N(L(x),N(y,z))) -> max(N(L(x),L(max(N(y,z))))) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: max#(N(L(s(x)),L(s(y)))) -> max#(N(L(x),L(y))) p2: max#(N(L(x),N(y,z))) -> max#(N(L(x),L(max(N(y,z))))) p3: max#(N(L(x),N(y,z))) -> max#(N(y,z)) and R consists of: r1: max(L(x)) -> x r2: max(N(L(|0|()),L(y))) -> y r3: max(N(L(s(x)),L(s(y)))) -> s(max(N(L(x),L(y)))) r4: max(N(L(x),N(y,z))) -> max(N(L(x),L(max(N(y,z))))) The estimated dependency graph contains the following SCCs: {p3} {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: max#(N(L(x),N(y,z))) -> max#(N(y,z)) and R consists of: r1: max(L(x)) -> x r2: max(N(L(|0|()),L(y))) -> y r3: max(N(L(s(x)),L(s(y)))) -> s(max(N(L(x),L(y)))) r4: max(N(L(x),N(y,z))) -> max(N(L(x),L(max(N(y,z))))) The set of usable rules consists of (no rules) Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: max#_A(x1) = ((1,0),(0,0)) x1 + (0,2) N_A(x1,x2) = ((1,0),(1,1)) x1 + ((1,0),(1,1)) x2 + (2,3) L_A(x1) = (1,1) precedence: N > L > max# partial status: pi(max#) = [] pi(N) = [1, 2] pi(L) = [] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: max#_A(x1) = (0,0) N_A(x1,x2) = x1 + x2 + (2,2) L_A(x1) = (1,1) precedence: L > max# = N partial status: pi(max#) = [] pi(N) = [1, 2] pi(L) = [] 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: max#(N(L(s(x)),L(s(y)))) -> max#(N(L(x),L(y))) and R consists of: r1: max(L(x)) -> x r2: max(N(L(|0|()),L(y))) -> y r3: max(N(L(s(x)),L(s(y)))) -> s(max(N(L(x),L(y)))) r4: max(N(L(x),N(y,z))) -> max(N(L(x),L(max(N(y,z))))) The set of usable rules consists of (no rules) Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: max#_A(x1) = x1 + (0,1) N_A(x1,x2) = ((0,0),(1,0)) x2 + (1,1) L_A(x1) = ((1,0),(1,1)) x1 + (2,5) s_A(x1) = x1 + (3,6) precedence: N = L > max# > s partial status: pi(max#) = [1] pi(N) = [] pi(L) = [1] pi(s) = [1] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: max#_A(x1) = (1,1) N_A(x1,x2) = (2,2) L_A(x1) = (2,2) s_A(x1) = ((0,0),(1,0)) x1 + (3,3) precedence: N > max# = L = s partial status: pi(max#) = [] pi(N) = [] pi(L) = [] pi(s) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.