YES We show the termination of the TRS R: f(s(x),y) -> f(x,s(x)) f(x,s(y)) -> f(y,x) f(c(x),y) -> f(x,s(x)) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: f#(s(x),y) -> f#(x,s(x)) p2: f#(x,s(y)) -> f#(y,x) p3: f#(c(x),y) -> f#(x,s(x)) and R consists of: r1: f(s(x),y) -> f(x,s(x)) r2: f(x,s(y)) -> f(y,x) r3: f(c(x),y) -> f(x,s(x)) The estimated dependency graph contains the following SCCs: {p1, p2, p3} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: f#(s(x),y) -> f#(x,s(x)) p2: f#(c(x),y) -> f#(x,s(x)) p3: f#(x,s(y)) -> f#(y,x) and R consists of: r1: f(s(x),y) -> f(x,s(x)) r2: f(x,s(y)) -> f(y,x) r3: f(c(x),y) -> f(x,s(x)) The set of usable rules consists of (no rules) Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: max/plus interpretation on natural numbers: f#_A(x1,x2) = 3 s_A(x1) = max{11, x1 + 2} c_A(x1) = max{5, x1 - 3} base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: f#_A(x1,x2) = max{0, x1 - 18, x2 - 24} s_A(x1) = max{17, x1 + 6} c_A(x1) = max{3, x1} f#!_A(x1,x2) = max{6, x1 - 10, x2 - 16} s!_A(x1) = max{14, x1 - 3} c!_A(x1) = max{10, x1 - 1} partial status: pi(f#) = [] pi(s) = [] pi(c) = [] The following rules are removed: p1 -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: f#(c(x),y) -> f#(x,s(x)) p2: f#(x,s(y)) -> f#(y,x) and R consists of: r1: f(s(x),y) -> f(x,s(x)) r2: f(x,s(y)) -> f(y,x) r3: f(c(x),y) -> f(x,s(x)) The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: f#(c(x),y) -> f#(x,s(x)) p2: f#(x,s(y)) -> f#(y,x) and R consists of: r1: f(s(x),y) -> f(x,s(x)) r2: f(x,s(y)) -> f(y,x) r3: f(c(x),y) -> f(x,s(x)) The set of usable rules consists of (no rules) Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: max/plus interpretation on natural numbers: f#_A(x1,x2) = 0 c_A(x1) = max{2, x1 - 4} s_A(x1) = max{5, x1 + 2} base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: f#_A(x1,x2) = max{0, x1 - 12, x2 - 13} c_A(x1) = max{11, x1 + 2} s_A(x1) = max{10, x1 + 3} f#!_A(x1,x2) = max{4, x1 - 3, x2 - 5} c!_A(x1) = max{2, x1 - 4} s!_A(x1) = max{3, x1 + 2} partial status: pi(f#) = [] pi(c) = [] pi(s) = [1] The following rules are removed: p1, p2 Then no dependency pair remains.