YES We show the termination of the TRS R: b(f(b(x,z)),y) -> f(f(f(b(z,b(y,z))))) c(f(f(c(x,a(),z))),a(),y) -> b(y,f(b(a(),z))) b(b(c(b(a(),a()),a(),z),f(a())),y) -> z -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: b#(f(b(x,z)),y) -> b#(z,b(y,z)) p2: b#(f(b(x,z)),y) -> b#(y,z) p3: c#(f(f(c(x,a(),z))),a(),y) -> b#(y,f(b(a(),z))) p4: c#(f(f(c(x,a(),z))),a(),y) -> b#(a(),z) and R consists of: r1: b(f(b(x,z)),y) -> f(f(f(b(z,b(y,z))))) r2: c(f(f(c(x,a(),z))),a(),y) -> b(y,f(b(a(),z))) r3: b(b(c(b(a(),a()),a(),z),f(a())),y) -> z The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: b#(f(b(x,z)),y) -> b#(z,b(y,z)) p2: b#(f(b(x,z)),y) -> b#(y,z) and R consists of: r1: b(f(b(x,z)),y) -> f(f(f(b(z,b(y,z))))) r2: c(f(f(c(x,a(),z))),a(),y) -> b(y,f(b(a(),z))) r3: b(b(c(b(a(),a()),a(),z),f(a())),y) -> z The set of usable rules consists of r1, r3 Take the reduction pair: lexicographic combination of reduction pairs: 1. weighted path order base order: matrix interpretations: carrier: N^2 order: standard order interpretations: b#_A(x1,x2) = ((0,1),(0,0)) x1 + ((0,1),(0,0)) x2 + (3,3) f_A(x1) = ((0,0),(1,0)) x1 + (1,0) b_A(x1,x2) = x1 + ((0,1),(0,0)) x2 + (2,1) c_A(x1,x2,x3) = ((0,0),(1,0)) x1 + ((1,0),(1,1)) x3 + (1,0) a_A() = (1,1) precedence: f = c > b# = b = a partial status: pi(b#) = [] pi(f) = [] pi(b) = [1] pi(c) = [3] pi(a) = [] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: standard order interpretations: b#_A(x1,x2) = (3,3) f_A(x1) = (1,1) b_A(x1,x2) = ((0,1),(0,1)) x1 + (2,2) c_A(x1,x2,x3) = ((0,0),(1,1)) x3 + (1,0) a_A() = (1,1) precedence: b# = b = c = a > f partial status: pi(b#) = [] pi(f) = [] pi(b) = [] pi(c) = [] pi(a) = [] The next rules are strictly ordered: p1 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: b#(f(b(x,z)),y) -> b#(y,z) and R consists of: r1: b(f(b(x,z)),y) -> f(f(f(b(z,b(y,z))))) r2: c(f(f(c(x,a(),z))),a(),y) -> b(y,f(b(a(),z))) r3: b(b(c(b(a(),a()),a(),z),f(a())),y) -> z The estimated dependency graph contains the following SCCs: {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: b#(f(b(x,z)),y) -> b#(y,z) and R consists of: r1: b(f(b(x,z)),y) -> f(f(f(b(z,b(y,z))))) r2: c(f(f(c(x,a(),z))),a(),y) -> b(y,f(b(a(),z))) r3: b(b(c(b(a(),a()),a(),z),f(a())),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: b#_A(x1,x2) = ((0,0),(1,0)) x1 + ((0,0),(1,0)) x2 + (1,1) f_A(x1) = x1 + (1,1) b_A(x1,x2) = x1 + ((1,0),(0,0)) x2 + (2,2) precedence: b# = f = b partial status: pi(b#) = [] pi(f) = [] pi(b) = [] 2. weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: b#_A(x1,x2) = (0,0) f_A(x1) = x1 + (1,1) b_A(x1,x2) = x1 + (1,1) precedence: f = b > b# partial status: pi(b#) = [] pi(f) = [1] pi(b) = [1] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.