YES We show the termination of the relative TRS R/S: R: f(|0|()) -> true() f(|1|()) -> false() f(s(x)) -> f(x) if(true(),s(x),s(y)) -> s(x) if(false(),s(x),s(y)) -> s(y) g(x,c(y)) -> c(g(x,y)) g(x,c(y)) -> g(x,if(f(x),c(g(s(x),y)),c(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)) -> f#(x) p2: g#(x,c(y)) -> g#(x,y) p3: g#(x,c(y)) -> g#(x,if(f(x),c(g(s(x),y)),c(y))) p4: g#(x,c(y)) -> if#(f(x),c(g(s(x),y)),c(y)) p5: g#(x,c(y)) -> f#(x) p6: g#(x,c(y)) -> g#(s(x),y) and R consists of: r1: f(|0|()) -> true() r2: f(|1|()) -> false() r3: f(s(x)) -> f(x) r4: if(true(),s(x),s(y)) -> s(x) r5: if(false(),s(x),s(y)) -> s(y) r6: g(x,c(y)) -> c(g(x,y)) r7: g(x,c(y)) -> g(x,if(f(x),c(g(s(x),y)),c(y))) r8: rand(x) -> x r9: rand(x) -> rand(s(x)) The estimated dependency graph contains the following SCCs: {p2, p6} {p1} -- Reduction pair. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: g#(x,c(y)) -> g#(s(x),y) p2: g#(x,c(y)) -> g#(x,y) and R consists of: r1: f(|0|()) -> true() r2: f(|1|()) -> false() r3: f(s(x)) -> f(x) r4: if(true(),s(x),s(y)) -> s(x) r5: if(false(),s(x),s(y)) -> s(y) r6: g(x,c(y)) -> c(g(x,y)) r7: g(x,c(y)) -> g(x,if(f(x),c(g(s(x),y)),c(y))) r8: rand(x) -> x r9: rand(x) -> rand(s(x)) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9 Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: g#_A(x1,x2) = max{2, x2 + 1} c_A(x1) = max{14, x1 + 6} s_A(x1) = 0 f_A(x1) = 22 |0|_A = 22 true_A = 21 |1|_A = 0 false_A = 5 if_A(x1,x2,x3) = max{5, x1 - 29, x2 - 7, x3} g_A(x1,x2) = x2 + 7 rand_A(x1) = x1 + 6 precedence: g# = c = s = f = |0| = true = |1| = false = if = g = rand partial status: pi(g#) = [2] pi(c) = [] pi(s) = [] pi(f) = [] pi(|0|) = [] pi(true) = [] pi(|1|) = [] pi(false) = [] pi(if) = [] pi(g) = [] 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: g#(x,c(y)) -> g#(s(x),y) and R consists of: r1: f(|0|()) -> true() r2: f(|1|()) -> false() r3: f(s(x)) -> f(x) r4: if(true(),s(x),s(y)) -> s(x) r5: if(false(),s(x),s(y)) -> s(y) r6: g(x,c(y)) -> c(g(x,y)) r7: g(x,c(y)) -> g(x,if(f(x),c(g(s(x),y)),c(y))) r8: rand(x) -> x r9: 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: g#(x,c(y)) -> g#(s(x),y) and R consists of: r1: f(|0|()) -> true() r2: f(|1|()) -> false() r3: f(s(x)) -> f(x) r4: if(true(),s(x),s(y)) -> s(x) r5: if(false(),s(x),s(y)) -> s(y) r6: g(x,c(y)) -> c(g(x,y)) r7: g(x,c(y)) -> g(x,if(f(x),c(g(s(x),y)),c(y))) r8: rand(x) -> x r9: rand(x) -> rand(s(x)) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9 Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: g#_A(x1,x2) = max{28, x1 + 14, x2 + 18} c_A(x1) = x1 + 18 s_A(x1) = 13 f_A(x1) = 2 |0|_A = 1 true_A = 0 |1|_A = 0 false_A = 1 if_A(x1,x2,x3) = x1 + 16 g_A(x1,x2) = x2 + 26 rand_A(x1) = max{28, x1 + 14} precedence: g# = c = s = f = |0| = true = |1| = false = if = g = rand partial status: pi(g#) = [2] pi(c) = [] pi(s) = [] pi(f) = [] pi(|0|) = [] pi(true) = [] pi(|1|) = [] pi(false) = [] pi(if) = [1] pi(g) = [] pi(rand) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: f#(s(x)) -> f#(x) and R consists of: r1: f(|0|()) -> true() r2: f(|1|()) -> false() r3: f(s(x)) -> f(x) r4: if(true(),s(x),s(y)) -> s(x) r5: if(false(),s(x),s(y)) -> s(y) r6: g(x,c(y)) -> c(g(x,y)) r7: g(x,c(y)) -> g(x,if(f(x),c(g(s(x),y)),c(y))) r8: rand(x) -> x r9: rand(x) -> rand(s(x)) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9 Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: f#_A(x1) = x1 s_A(x1) = x1 f_A(x1) = max{1, x1} |0|_A = 3 true_A = 2 |1|_A = 5 false_A = 4 if_A(x1,x2,x3) = max{7, x2 + 3, x3 + 3} g_A(x1,x2) = max{5, x2 - 2} c_A(x1) = 4 rand_A(x1) = max{2, x1 + 1} precedence: f = |0| = true = |1| = false = if = g = c = rand > s > f# partial status: pi(f#) = [1] pi(s) = [1] pi(f) = [1] pi(|0|) = [] pi(true) = [] pi(|1|) = [] pi(false) = [] pi(if) = [3] pi(g) = [] pi(c) = [] pi(rand) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.