YES We show the termination of the TRS R: f(s(x),y) -> f(x,s(x)) f(x,s(y)) -> f(y,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) and R consists of: r1: f(s(x),y) -> f(x,s(x)) r2: f(x,s(y)) -> f(y,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#(s(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) The set of usable rules consists of (no rules) Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: f#_A(x1,x2) = 1 s_A(x1) = 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 - 8, x2 - 8} s_A(x1) = max{7, x1 + 4} f#!_A(x1,x2) = max{4, x1 - 2, x2 - 6} s!_A(x1) = max{6, x1 + 3} partial status: pi(f#) = [] pi(s) = [] The following rules are removed: p1 -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: 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) The estimated dependency graph contains the following SCCs: {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: 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) The set of usable rules consists of (no rules) Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: f#_A(x1,x2) = x1 + x2 + 3 s_A(x1) = x1 + 2 base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: f#_A(x1,x2) = 0 s_A(x1) = x1 + 7 f#!_A(x1,x2) = max{2, x1 - 1, x2 - 9} s!_A(x1) = max{1, x1 - 2} partial status: pi(f#) = [1] pi(s) = [1] The following rules are removed: p1 Then no dependency pair remains.