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