YES We show the termination of the TRS R: a__2nd(cons(X,cons(Y,Z))) -> mark(Y) a__from(X) -> cons(mark(X),from(s(X))) mark(|2nd|(X)) -> a__2nd(mark(X)) mark(from(X)) -> a__from(mark(X)) mark(cons(X1,X2)) -> cons(mark(X1),X2) mark(s(X)) -> s(mark(X)) a__2nd(X) -> |2nd|(X) a__from(X) -> from(X) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: a__2nd#(cons(X,cons(Y,Z))) -> mark#(Y) p2: a__from#(X) -> mark#(X) p3: mark#(|2nd|(X)) -> a__2nd#(mark(X)) p4: mark#(|2nd|(X)) -> mark#(X) p5: mark#(from(X)) -> a__from#(mark(X)) p6: mark#(from(X)) -> mark#(X) p7: mark#(cons(X1,X2)) -> mark#(X1) p8: mark#(s(X)) -> mark#(X) and R consists of: r1: a__2nd(cons(X,cons(Y,Z))) -> mark(Y) r2: a__from(X) -> cons(mark(X),from(s(X))) r3: mark(|2nd|(X)) -> a__2nd(mark(X)) r4: mark(from(X)) -> a__from(mark(X)) r5: mark(cons(X1,X2)) -> cons(mark(X1),X2) r6: mark(s(X)) -> s(mark(X)) r7: a__2nd(X) -> |2nd|(X) r8: a__from(X) -> from(X) The estimated dependency graph contains the following SCCs: {p1, p2, p3, p4, p5, p6, p7, p8} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: a__2nd#(cons(X,cons(Y,Z))) -> mark#(Y) p2: mark#(s(X)) -> mark#(X) p3: mark#(cons(X1,X2)) -> mark#(X1) p4: mark#(from(X)) -> mark#(X) p5: mark#(from(X)) -> a__from#(mark(X)) p6: a__from#(X) -> mark#(X) p7: mark#(|2nd|(X)) -> mark#(X) p8: mark#(|2nd|(X)) -> a__2nd#(mark(X)) and R consists of: r1: a__2nd(cons(X,cons(Y,Z))) -> mark(Y) r2: a__from(X) -> cons(mark(X),from(s(X))) r3: mark(|2nd|(X)) -> a__2nd(mark(X)) r4: mark(from(X)) -> a__from(mark(X)) r5: mark(cons(X1,X2)) -> cons(mark(X1),X2) r6: mark(s(X)) -> s(mark(X)) r7: a__2nd(X) -> |2nd|(X) r8: a__from(X) -> from(X) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8 Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: a__2nd#_A(x1) = max{14, x1 + 9} cons_A(x1,x2) = max{24, x1, x2 - 10} mark#_A(x1) = max{13, x1 - 2} s_A(x1) = max{4, x1 + 3} from_A(x1) = x1 + 30 a__from#_A(x1) = max{28, x1 + 27} mark_A(x1) = x1 |2nd|_A(x1) = x1 + 16 a__2nd_A(x1) = x1 + 16 a__from_A(x1) = x1 + 30 precedence: a__2nd# = cons = mark# = s = mark > a__from# > |2nd| = a__2nd > from = a__from partial status: pi(a__2nd#) = [] pi(cons) = [] pi(mark#) = [] pi(s) = [] pi(from) = [] pi(a__from#) = [] pi(mark) = [] pi(|2nd|) = [] pi(a__2nd) = [] pi(a__from) = [] The next rules are strictly ordered: p5 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: a__2nd#(cons(X,cons(Y,Z))) -> mark#(Y) p2: mark#(s(X)) -> mark#(X) p3: mark#(cons(X1,X2)) -> mark#(X1) p4: mark#(from(X)) -> mark#(X) p5: a__from#(X) -> mark#(X) p6: mark#(|2nd|(X)) -> mark#(X) p7: mark#(|2nd|(X)) -> a__2nd#(mark(X)) and R consists of: r1: a__2nd(cons(X,cons(Y,Z))) -> mark(Y) r2: a__from(X) -> cons(mark(X),from(s(X))) r3: mark(|2nd|(X)) -> a__2nd(mark(X)) r4: mark(from(X)) -> a__from(mark(X)) r5: mark(cons(X1,X2)) -> cons(mark(X1),X2) r6: mark(s(X)) -> s(mark(X)) r7: a__2nd(X) -> |2nd|(X) r8: a__from(X) -> from(X) The estimated dependency graph contains the following SCCs: {p1, p2, p3, p4, p6, p7} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: a__2nd#(cons(X,cons(Y,Z))) -> mark#(Y) p2: mark#(|2nd|(X)) -> a__2nd#(mark(X)) p3: mark#(|2nd|(X)) -> mark#(X) p4: mark#(from(X)) -> mark#(X) p5: mark#(cons(X1,X2)) -> mark#(X1) p6: mark#(s(X)) -> mark#(X) and R consists of: r1: a__2nd(cons(X,cons(Y,Z))) -> mark(Y) r2: a__from(X) -> cons(mark(X),from(s(X))) r3: mark(|2nd|(X)) -> a__2nd(mark(X)) r4: mark(from(X)) -> a__from(mark(X)) r5: mark(cons(X1,X2)) -> cons(mark(X1),X2) r6: mark(s(X)) -> s(mark(X)) r7: a__2nd(X) -> |2nd|(X) r8: a__from(X) -> from(X) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8 Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: a__2nd#_A(x1) = x1 + 9 cons_A(x1,x2) = max{x1 + 11, x2 - 5} mark#_A(x1) = x1 + 5 |2nd|_A(x1) = x1 + 4 mark_A(x1) = x1 from_A(x1) = x1 + 12 s_A(x1) = x1 + 5 a__2nd_A(x1) = x1 + 4 a__from_A(x1) = x1 + 12 precedence: a__2nd# = cons = mark# = |2nd| = mark = from = s = a__2nd = a__from partial status: pi(a__2nd#) = [] pi(cons) = [] pi(mark#) = [1] pi(|2nd|) = [1] pi(mark) = [1] pi(from) = [] pi(s) = [1] pi(a__2nd) = [1] pi(a__from) = [] The next rules are strictly ordered: p4 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: a__2nd#(cons(X,cons(Y,Z))) -> mark#(Y) p2: mark#(|2nd|(X)) -> a__2nd#(mark(X)) p3: mark#(|2nd|(X)) -> mark#(X) p4: mark#(cons(X1,X2)) -> mark#(X1) p5: mark#(s(X)) -> mark#(X) and R consists of: r1: a__2nd(cons(X,cons(Y,Z))) -> mark(Y) r2: a__from(X) -> cons(mark(X),from(s(X))) r3: mark(|2nd|(X)) -> a__2nd(mark(X)) r4: mark(from(X)) -> a__from(mark(X)) r5: mark(cons(X1,X2)) -> cons(mark(X1),X2) r6: mark(s(X)) -> s(mark(X)) r7: a__2nd(X) -> |2nd|(X) r8: a__from(X) -> from(X) 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: a__2nd#(cons(X,cons(Y,Z))) -> mark#(Y) p2: mark#(s(X)) -> mark#(X) p3: mark#(cons(X1,X2)) -> mark#(X1) p4: mark#(|2nd|(X)) -> mark#(X) p5: mark#(|2nd|(X)) -> a__2nd#(mark(X)) and R consists of: r1: a__2nd(cons(X,cons(Y,Z))) -> mark(Y) r2: a__from(X) -> cons(mark(X),from(s(X))) r3: mark(|2nd|(X)) -> a__2nd(mark(X)) r4: mark(from(X)) -> a__from(mark(X)) r5: mark(cons(X1,X2)) -> cons(mark(X1),X2) r6: mark(s(X)) -> s(mark(X)) r7: a__2nd(X) -> |2nd|(X) r8: a__from(X) -> from(X) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8 Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: a__2nd#_A(x1) = max{23, x1 + 22} cons_A(x1,x2) = max{x1 + 15, x2 - 8} mark#_A(x1) = x1 + 8 s_A(x1) = x1 + 8 |2nd|_A(x1) = x1 + 17 mark_A(x1) = x1 a__2nd_A(x1) = x1 + 17 a__from_A(x1) = x1 + 15 from_A(x1) = x1 + 15 precedence: a__2nd# = cons = mark# = s = |2nd| = mark = a__2nd = a__from = from partial status: pi(a__2nd#) = [1] pi(cons) = [] pi(mark#) = [1] pi(s) = [1] pi(|2nd|) = [] pi(mark) = [1] pi(a__2nd) = [1] pi(a__from) = [] pi(from) = [] 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: mark#(s(X)) -> mark#(X) p2: mark#(cons(X1,X2)) -> mark#(X1) p3: mark#(|2nd|(X)) -> mark#(X) p4: mark#(|2nd|(X)) -> a__2nd#(mark(X)) and R consists of: r1: a__2nd(cons(X,cons(Y,Z))) -> mark(Y) r2: a__from(X) -> cons(mark(X),from(s(X))) r3: mark(|2nd|(X)) -> a__2nd(mark(X)) r4: mark(from(X)) -> a__from(mark(X)) r5: mark(cons(X1,X2)) -> cons(mark(X1),X2) r6: mark(s(X)) -> s(mark(X)) r7: a__2nd(X) -> |2nd|(X) r8: a__from(X) -> from(X) 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: mark#(s(X)) -> mark#(X) p2: mark#(|2nd|(X)) -> mark#(X) p3: mark#(cons(X1,X2)) -> mark#(X1) and R consists of: r1: a__2nd(cons(X,cons(Y,Z))) -> mark(Y) r2: a__from(X) -> cons(mark(X),from(s(X))) r3: mark(|2nd|(X)) -> a__2nd(mark(X)) r4: mark(from(X)) -> a__from(mark(X)) r5: mark(cons(X1,X2)) -> cons(mark(X1),X2) r6: mark(s(X)) -> s(mark(X)) r7: a__2nd(X) -> |2nd|(X) r8: a__from(X) -> from(X) The set of usable rules consists of (no rules) Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: mark#_A(x1) = max{4, x1 + 2} s_A(x1) = max{3, x1 + 1} |2nd|_A(x1) = x1 + 2 cons_A(x1,x2) = max{x1, x2} precedence: s = |2nd| > mark# = cons partial status: pi(mark#) = [] pi(s) = [1] pi(|2nd|) = [1] pi(cons) = [2] 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: mark#(|2nd|(X)) -> mark#(X) p2: mark#(cons(X1,X2)) -> mark#(X1) and R consists of: r1: a__2nd(cons(X,cons(Y,Z))) -> mark(Y) r2: a__from(X) -> cons(mark(X),from(s(X))) r3: mark(|2nd|(X)) -> a__2nd(mark(X)) r4: mark(from(X)) -> a__from(mark(X)) r5: mark(cons(X1,X2)) -> cons(mark(X1),X2) r6: mark(s(X)) -> s(mark(X)) r7: a__2nd(X) -> |2nd|(X) r8: a__from(X) -> from(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: mark#(|2nd|(X)) -> mark#(X) p2: mark#(cons(X1,X2)) -> mark#(X1) and R consists of: r1: a__2nd(cons(X,cons(Y,Z))) -> mark(Y) r2: a__from(X) -> cons(mark(X),from(s(X))) r3: mark(|2nd|(X)) -> a__2nd(mark(X)) r4: mark(from(X)) -> a__from(mark(X)) r5: mark(cons(X1,X2)) -> cons(mark(X1),X2) r6: mark(s(X)) -> s(mark(X)) r7: a__2nd(X) -> |2nd|(X) r8: a__from(X) -> from(X) The set of usable rules consists of (no rules) Take the monotone reduction pair: weighted path order base order: max/plus interpretations on natural numbers: mark#_A(x1) = x1 + 1 |2nd|_A(x1) = x1 cons_A(x1,x2) = max{x1, x2} precedence: mark# = |2nd| = cons partial status: pi(mark#) = [1] pi(|2nd|) = [1] pi(cons) = [1, 2] 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: mark#(cons(X1,X2)) -> mark#(X1) and R consists of: r1: a__2nd(cons(X,cons(Y,Z))) -> mark(Y) r2: a__from(X) -> cons(mark(X),from(s(X))) r3: mark(|2nd|(X)) -> a__2nd(mark(X)) r4: mark(from(X)) -> a__from(mark(X)) r5: mark(cons(X1,X2)) -> cons(mark(X1),X2) r6: mark(s(X)) -> s(mark(X)) r7: a__2nd(X) -> |2nd|(X) r8: a__from(X) -> from(X) The estimated dependency graph contains the following SCCs: {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: mark#(cons(X1,X2)) -> mark#(X1) and R consists of: r1: a__2nd(cons(X,cons(Y,Z))) -> mark(Y) r2: a__from(X) -> cons(mark(X),from(s(X))) r3: mark(|2nd|(X)) -> a__2nd(mark(X)) r4: mark(from(X)) -> a__from(mark(X)) r5: mark(cons(X1,X2)) -> cons(mark(X1),X2) r6: mark(s(X)) -> s(mark(X)) r7: a__2nd(X) -> |2nd|(X) r8: a__from(X) -> from(X) The set of usable rules consists of (no rules) Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: mark#_A(x1) = x1 + 2 cons_A(x1,x2) = max{x1 + 1, x2 + 1} precedence: mark# = cons partial status: pi(mark#) = [] pi(cons) = [2] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.