YES We show the termination of the TRS R: b(x,y) -> c(a(c(y),a(|0|(),x))) a(y,x) -> y a(y,c(b(a(|0|(),x),|0|()))) -> b(a(c(b(|0|(),y)),x),|0|()) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: b#(x,y) -> a#(c(y),a(|0|(),x)) p2: b#(x,y) -> a#(|0|(),x) p3: a#(y,c(b(a(|0|(),x),|0|()))) -> b#(a(c(b(|0|(),y)),x),|0|()) p4: a#(y,c(b(a(|0|(),x),|0|()))) -> a#(c(b(|0|(),y)),x) p5: a#(y,c(b(a(|0|(),x),|0|()))) -> b#(|0|(),y) and R consists of: r1: b(x,y) -> c(a(c(y),a(|0|(),x))) r2: a(y,x) -> y r3: a(y,c(b(a(|0|(),x),|0|()))) -> b(a(c(b(|0|(),y)),x),|0|()) The estimated dependency graph contains the following SCCs: {p1, p2, p3, p4, p5} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: b#(x,y) -> a#(c(y),a(|0|(),x)) p2: a#(y,c(b(a(|0|(),x),|0|()))) -> b#(|0|(),y) p3: b#(x,y) -> a#(|0|(),x) p4: a#(y,c(b(a(|0|(),x),|0|()))) -> a#(c(b(|0|(),y)),x) p5: a#(y,c(b(a(|0|(),x),|0|()))) -> b#(a(c(b(|0|(),y)),x),|0|()) and R consists of: r1: b(x,y) -> c(a(c(y),a(|0|(),x))) r2: a(y,x) -> y r3: a(y,c(b(a(|0|(),x),|0|()))) -> b(a(c(b(|0|(),y)),x),|0|()) The set of usable rules consists of r1, r2, r3 Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: b#_A(x1,x2) = max{120, x1 + 80, x2 + 59} a#_A(x1,x2) = max{89, x1 + 59, x2 + 67} c_A(x1) = max{23, x1 - 12} a_A(x1,x2) = max{40, x1 + 1, x2 + 12} |0|_A = 0 b_A(x1,x2) = max{41, x1 + 25, x2 - 13} precedence: b# = a# = c = a = |0| = b partial status: pi(b#) = [] pi(a#) = [2] pi(c) = [] pi(a) = [2] pi(|0|) = [] pi(b) = [] The next rules are strictly ordered: p3 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: b#(x,y) -> a#(c(y),a(|0|(),x)) p2: a#(y,c(b(a(|0|(),x),|0|()))) -> b#(|0|(),y) p3: a#(y,c(b(a(|0|(),x),|0|()))) -> a#(c(b(|0|(),y)),x) p4: a#(y,c(b(a(|0|(),x),|0|()))) -> b#(a(c(b(|0|(),y)),x),|0|()) and R consists of: r1: b(x,y) -> c(a(c(y),a(|0|(),x))) r2: a(y,x) -> y r3: a(y,c(b(a(|0|(),x),|0|()))) -> b(a(c(b(|0|(),y)),x),|0|()) The estimated dependency graph contains the following SCCs: {p1, p2, p3, p4} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: b#(x,y) -> a#(c(y),a(|0|(),x)) p2: a#(y,c(b(a(|0|(),x),|0|()))) -> b#(a(c(b(|0|(),y)),x),|0|()) p3: a#(y,c(b(a(|0|(),x),|0|()))) -> a#(c(b(|0|(),y)),x) p4: a#(y,c(b(a(|0|(),x),|0|()))) -> b#(|0|(),y) and R consists of: r1: b(x,y) -> c(a(c(y),a(|0|(),x))) r2: a(y,x) -> y r3: a(y,c(b(a(|0|(),x),|0|()))) -> b(a(c(b(|0|(),y)),x),|0|()) The set of usable rules consists of r1, r2, r3 Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: b#_A(x1,x2) = max{35, x1 + 20, x2 + 2} a#_A(x1,x2) = max{x1 + 3, x2 + 5} c_A(x1) = max{20, x1 - 10} a_A(x1,x2) = max{20, x1, x2 + 15} |0|_A = 0 b_A(x1,x2) = max{x1 + 25, x2 - 16} precedence: b# = a# = c = a = |0| = b partial status: pi(b#) = [] pi(a#) = [] pi(c) = [] pi(a) = [1, 2] pi(|0|) = [] pi(b) = [] The next rules are strictly ordered: p3 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: b#(x,y) -> a#(c(y),a(|0|(),x)) p2: a#(y,c(b(a(|0|(),x),|0|()))) -> b#(a(c(b(|0|(),y)),x),|0|()) p3: a#(y,c(b(a(|0|(),x),|0|()))) -> b#(|0|(),y) and R consists of: r1: b(x,y) -> c(a(c(y),a(|0|(),x))) r2: a(y,x) -> y r3: a(y,c(b(a(|0|(),x),|0|()))) -> b(a(c(b(|0|(),y)),x),|0|()) 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: b#(x,y) -> a#(c(y),a(|0|(),x)) p2: a#(y,c(b(a(|0|(),x),|0|()))) -> b#(|0|(),y) p3: a#(y,c(b(a(|0|(),x),|0|()))) -> b#(a(c(b(|0|(),y)),x),|0|()) and R consists of: r1: b(x,y) -> c(a(c(y),a(|0|(),x))) r2: a(y,x) -> y r3: a(y,c(b(a(|0|(),x),|0|()))) -> b(a(c(b(|0|(),y)),x),|0|()) The set of usable rules consists of r1, r2, r3 Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: b#_A(x1,x2) = max{152, x1 + 123, x2 + 129} a#_A(x1,x2) = max{x1 + 134, x2 + 97} c_A(x1) = max{0, x1 - 17} a_A(x1,x2) = max{29, x1 + 2, x2 + 25} |0|_A = 1 b_A(x1,x2) = max{x1 + 48, x2 - 31} precedence: b# = a# = c = a = |0| = b partial status: pi(b#) = [] pi(a#) = [2] pi(c) = [] pi(a) = [2] pi(|0|) = [] pi(b) = [] 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: a#(y,c(b(a(|0|(),x),|0|()))) -> b#(|0|(),y) p2: a#(y,c(b(a(|0|(),x),|0|()))) -> b#(a(c(b(|0|(),y)),x),|0|()) and R consists of: r1: b(x,y) -> c(a(c(y),a(|0|(),x))) r2: a(y,x) -> y r3: a(y,c(b(a(|0|(),x),|0|()))) -> b(a(c(b(|0|(),y)),x),|0|()) The estimated dependency graph contains the following SCCs: (no SCCs)