YES We show the termination of the TRS R: a__first(|0|(),X) -> nil() a__first(s(X),cons(Y,Z)) -> cons(mark(Y),first(X,Z)) a__from(X) -> cons(mark(X),from(s(X))) mark(first(X1,X2)) -> a__first(mark(X1),mark(X2)) mark(from(X)) -> a__from(mark(X)) mark(|0|()) -> |0|() mark(nil()) -> nil() mark(s(X)) -> s(mark(X)) mark(cons(X1,X2)) -> cons(mark(X1),X2) a__first(X1,X2) -> first(X1,X2) a__from(X) -> from(X) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: a__first#(s(X),cons(Y,Z)) -> mark#(Y) p2: a__from#(X) -> mark#(X) p3: mark#(first(X1,X2)) -> a__first#(mark(X1),mark(X2)) p4: mark#(first(X1,X2)) -> mark#(X1) p5: mark#(first(X1,X2)) -> mark#(X2) p6: mark#(from(X)) -> a__from#(mark(X)) p7: mark#(from(X)) -> mark#(X) p8: mark#(s(X)) -> mark#(X) p9: mark#(cons(X1,X2)) -> mark#(X1) and R consists of: r1: a__first(|0|(),X) -> nil() r2: a__first(s(X),cons(Y,Z)) -> cons(mark(Y),first(X,Z)) r3: a__from(X) -> cons(mark(X),from(s(X))) r4: mark(first(X1,X2)) -> a__first(mark(X1),mark(X2)) r5: mark(from(X)) -> a__from(mark(X)) r6: mark(|0|()) -> |0|() r7: mark(nil()) -> nil() r8: mark(s(X)) -> s(mark(X)) r9: mark(cons(X1,X2)) -> cons(mark(X1),X2) r10: a__first(X1,X2) -> first(X1,X2) r11: a__from(X) -> from(X) The estimated dependency graph contains the following SCCs: {p1, p2, p3, p4, p5, p6, p7, p8, p9} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: a__first#(s(X),cons(Y,Z)) -> mark#(Y) p2: mark#(cons(X1,X2)) -> mark#(X1) p3: mark#(s(X)) -> mark#(X) p4: mark#(from(X)) -> mark#(X) p5: mark#(from(X)) -> a__from#(mark(X)) p6: a__from#(X) -> mark#(X) p7: mark#(first(X1,X2)) -> mark#(X2) p8: mark#(first(X1,X2)) -> mark#(X1) p9: mark#(first(X1,X2)) -> a__first#(mark(X1),mark(X2)) and R consists of: r1: a__first(|0|(),X) -> nil() r2: a__first(s(X),cons(Y,Z)) -> cons(mark(Y),first(X,Z)) r3: a__from(X) -> cons(mark(X),from(s(X))) r4: mark(first(X1,X2)) -> a__first(mark(X1),mark(X2)) r5: mark(from(X)) -> a__from(mark(X)) r6: mark(|0|()) -> |0|() r7: mark(nil()) -> nil() r8: mark(s(X)) -> s(mark(X)) r9: mark(cons(X1,X2)) -> cons(mark(X1),X2) r10: a__first(X1,X2) -> first(X1,X2) r11: a__from(X) -> from(X) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11 Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: a__first#_A(x1,x2) = max{x1 + 2, x2 + 7} s_A(x1) = x1 + 3 cons_A(x1,x2) = max{10, x1 + 4, x2 - 3} mark#_A(x1) = max{3, x1} from_A(x1) = max{12, x1 + 11} a__from#_A(x1) = x1 + 10 mark_A(x1) = x1 first_A(x1,x2) = max{x1 + 8, x2 + 10} a__first_A(x1,x2) = max{x1 + 8, x2 + 10} |0|_A = 4 nil_A = 11 a__from_A(x1) = max{12, x1 + 11} precedence: s = |0| = nil > first = a__first > a__first# > mark# > cons = from = a__from# = mark = a__from partial status: pi(a__first#) = [1] pi(s) = [] pi(cons) = [] pi(mark#) = [1] pi(from) = [] pi(a__from#) = [] pi(mark) = [1] pi(first) = [] pi(a__first) = [] pi(|0|) = [] pi(nil) = [] pi(a__from) = [] The next rules are strictly ordered: p9 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: a__first#(s(X),cons(Y,Z)) -> mark#(Y) p2: mark#(cons(X1,X2)) -> mark#(X1) p3: mark#(s(X)) -> mark#(X) p4: mark#(from(X)) -> mark#(X) p5: mark#(from(X)) -> a__from#(mark(X)) p6: a__from#(X) -> mark#(X) p7: mark#(first(X1,X2)) -> mark#(X2) p8: mark#(first(X1,X2)) -> mark#(X1) and R consists of: r1: a__first(|0|(),X) -> nil() r2: a__first(s(X),cons(Y,Z)) -> cons(mark(Y),first(X,Z)) r3: a__from(X) -> cons(mark(X),from(s(X))) r4: mark(first(X1,X2)) -> a__first(mark(X1),mark(X2)) r5: mark(from(X)) -> a__from(mark(X)) r6: mark(|0|()) -> |0|() r7: mark(nil()) -> nil() r8: mark(s(X)) -> s(mark(X)) r9: mark(cons(X1,X2)) -> cons(mark(X1),X2) r10: a__first(X1,X2) -> first(X1,X2) r11: a__from(X) -> from(X) The estimated dependency graph contains the following SCCs: {p2, p3, p4, p5, p6, p7, p8} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: mark#(cons(X1,X2)) -> mark#(X1) p2: mark#(first(X1,X2)) -> mark#(X1) p3: mark#(first(X1,X2)) -> mark#(X2) p4: mark#(from(X)) -> a__from#(mark(X)) p5: a__from#(X) -> mark#(X) p6: mark#(from(X)) -> mark#(X) p7: mark#(s(X)) -> mark#(X) and R consists of: r1: a__first(|0|(),X) -> nil() r2: a__first(s(X),cons(Y,Z)) -> cons(mark(Y),first(X,Z)) r3: a__from(X) -> cons(mark(X),from(s(X))) r4: mark(first(X1,X2)) -> a__first(mark(X1),mark(X2)) r5: mark(from(X)) -> a__from(mark(X)) r6: mark(|0|()) -> |0|() r7: mark(nil()) -> nil() r8: mark(s(X)) -> s(mark(X)) r9: mark(cons(X1,X2)) -> cons(mark(X1),X2) r10: a__first(X1,X2) -> first(X1,X2) r11: a__from(X) -> from(X) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11 Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: mark#_A(x1) = max{4, x1 + 2} cons_A(x1,x2) = max{42, x1 + 6, x2 - 10} first_A(x1,x2) = max{x1 + 40, x2 + 34} from_A(x1) = x1 + 45 a__from#_A(x1) = max{44, x1 + 5} mark_A(x1) = x1 + 34 s_A(x1) = max{6, x1 + 3} a__first_A(x1,x2) = max{x1 + 40, x2 + 34} |0|_A = 7 nil_A = 6 a__from_A(x1) = x1 + 45 precedence: mark = nil = a__from > s > |0| > cons = first = a__first > mark# = from = a__from# partial status: pi(mark#) = [1] pi(cons) = [] pi(first) = [1] pi(from) = [1] pi(a__from#) = [1] pi(mark) = [1] pi(s) = [1] pi(a__first) = [1] pi(|0|) = [] pi(nil) = [] pi(a__from) = [1] 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: mark#(cons(X1,X2)) -> mark#(X1) p2: mark#(first(X1,X2)) -> mark#(X1) p3: mark#(first(X1,X2)) -> mark#(X2) p4: a__from#(X) -> mark#(X) p5: mark#(from(X)) -> mark#(X) p6: mark#(s(X)) -> mark#(X) and R consists of: r1: a__first(|0|(),X) -> nil() r2: a__first(s(X),cons(Y,Z)) -> cons(mark(Y),first(X,Z)) r3: a__from(X) -> cons(mark(X),from(s(X))) r4: mark(first(X1,X2)) -> a__first(mark(X1),mark(X2)) r5: mark(from(X)) -> a__from(mark(X)) r6: mark(|0|()) -> |0|() r7: mark(nil()) -> nil() r8: mark(s(X)) -> s(mark(X)) r9: mark(cons(X1,X2)) -> cons(mark(X1),X2) r10: a__first(X1,X2) -> first(X1,X2) r11: a__from(X) -> from(X) The estimated dependency graph contains the following SCCs: {p1, p2, p3, p5, p6} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: mark#(cons(X1,X2)) -> mark#(X1) p2: mark#(s(X)) -> mark#(X) p3: mark#(from(X)) -> mark#(X) p4: mark#(first(X1,X2)) -> mark#(X2) p5: mark#(first(X1,X2)) -> mark#(X1) and R consists of: r1: a__first(|0|(),X) -> nil() r2: a__first(s(X),cons(Y,Z)) -> cons(mark(Y),first(X,Z)) r3: a__from(X) -> cons(mark(X),from(s(X))) r4: mark(first(X1,X2)) -> a__first(mark(X1),mark(X2)) r5: mark(from(X)) -> a__from(mark(X)) r6: mark(|0|()) -> |0|() r7: mark(nil()) -> nil() r8: mark(s(X)) -> s(mark(X)) r9: mark(cons(X1,X2)) -> cons(mark(X1),X2) r10: a__first(X1,X2) -> first(X1,X2) r11: 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 + 3} cons_A(x1,x2) = max{x1, x2} s_A(x1) = x1 + 2 from_A(x1) = x1 first_A(x1,x2) = max{x1 + 1, x2} precedence: mark# = cons = s = from = first partial status: pi(mark#) = [] pi(cons) = [2] pi(s) = [1] pi(from) = [1] pi(first) = [2] The next rules are strictly ordered: p2 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) p2: mark#(from(X)) -> mark#(X) p3: mark#(first(X1,X2)) -> mark#(X2) p4: mark#(first(X1,X2)) -> mark#(X1) and R consists of: r1: a__first(|0|(),X) -> nil() r2: a__first(s(X),cons(Y,Z)) -> cons(mark(Y),first(X,Z)) r3: a__from(X) -> cons(mark(X),from(s(X))) r4: mark(first(X1,X2)) -> a__first(mark(X1),mark(X2)) r5: mark(from(X)) -> a__from(mark(X)) r6: mark(|0|()) -> |0|() r7: mark(nil()) -> nil() r8: mark(s(X)) -> s(mark(X)) r9: mark(cons(X1,X2)) -> cons(mark(X1),X2) r10: a__first(X1,X2) -> first(X1,X2) r11: a__from(X) -> from(X) 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: mark#(cons(X1,X2)) -> mark#(X1) p2: mark#(first(X1,X2)) -> mark#(X1) p3: mark#(first(X1,X2)) -> mark#(X2) p4: mark#(from(X)) -> mark#(X) and R consists of: r1: a__first(|0|(),X) -> nil() r2: a__first(s(X),cons(Y,Z)) -> cons(mark(Y),first(X,Z)) r3: a__from(X) -> cons(mark(X),from(s(X))) r4: mark(first(X1,X2)) -> a__first(mark(X1),mark(X2)) r5: mark(from(X)) -> a__from(mark(X)) r6: mark(|0|()) -> |0|() r7: mark(nil()) -> nil() r8: mark(s(X)) -> s(mark(X)) r9: mark(cons(X1,X2)) -> cons(mark(X1),X2) r10: a__first(X1,X2) -> first(X1,X2) r11: 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 cons_A(x1,x2) = max{x1, x2} first_A(x1,x2) = max{x1, x2} from_A(x1) = x1 precedence: mark# = cons = first = from partial status: pi(mark#) = [1] pi(cons) = [1, 2] pi(first) = [1, 2] pi(from) = [1] 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#(first(X1,X2)) -> mark#(X1) p2: mark#(first(X1,X2)) -> mark#(X2) p3: mark#(from(X)) -> mark#(X) and R consists of: r1: a__first(|0|(),X) -> nil() r2: a__first(s(X),cons(Y,Z)) -> cons(mark(Y),first(X,Z)) r3: a__from(X) -> cons(mark(X),from(s(X))) r4: mark(first(X1,X2)) -> a__first(mark(X1),mark(X2)) r5: mark(from(X)) -> a__from(mark(X)) r6: mark(|0|()) -> |0|() r7: mark(nil()) -> nil() r8: mark(s(X)) -> s(mark(X)) r9: mark(cons(X1,X2)) -> cons(mark(X1),X2) r10: a__first(X1,X2) -> first(X1,X2) r11: 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#(first(X1,X2)) -> mark#(X1) p2: mark#(from(X)) -> mark#(X) p3: mark#(first(X1,X2)) -> mark#(X2) and R consists of: r1: a__first(|0|(),X) -> nil() r2: a__first(s(X),cons(Y,Z)) -> cons(mark(Y),first(X,Z)) r3: a__from(X) -> cons(mark(X),from(s(X))) r4: mark(first(X1,X2)) -> a__first(mark(X1),mark(X2)) r5: mark(from(X)) -> a__from(mark(X)) r6: mark(|0|()) -> |0|() r7: mark(nil()) -> nil() r8: mark(s(X)) -> s(mark(X)) r9: mark(cons(X1,X2)) -> cons(mark(X1),X2) r10: a__first(X1,X2) -> first(X1,X2) r11: 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 + 3} first_A(x1,x2) = max{x1 + 1, x2} from_A(x1) = x1 + 2 precedence: mark# = first = from partial status: pi(mark#) = [] pi(first) = [2] pi(from) = [1] The next rules are strictly ordered: p2 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: mark#(first(X1,X2)) -> mark#(X1) p2: mark#(first(X1,X2)) -> mark#(X2) and R consists of: r1: a__first(|0|(),X) -> nil() r2: a__first(s(X),cons(Y,Z)) -> cons(mark(Y),first(X,Z)) r3: a__from(X) -> cons(mark(X),from(s(X))) r4: mark(first(X1,X2)) -> a__first(mark(X1),mark(X2)) r5: mark(from(X)) -> a__from(mark(X)) r6: mark(|0|()) -> |0|() r7: mark(nil()) -> nil() r8: mark(s(X)) -> s(mark(X)) r9: mark(cons(X1,X2)) -> cons(mark(X1),X2) r10: a__first(X1,X2) -> first(X1,X2) r11: 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#(first(X1,X2)) -> mark#(X1) p2: mark#(first(X1,X2)) -> mark#(X2) and R consists of: r1: a__first(|0|(),X) -> nil() r2: a__first(s(X),cons(Y,Z)) -> cons(mark(Y),first(X,Z)) r3: a__from(X) -> cons(mark(X),from(s(X))) r4: mark(first(X1,X2)) -> a__first(mark(X1),mark(X2)) r5: mark(from(X)) -> a__from(mark(X)) r6: mark(|0|()) -> |0|() r7: mark(nil()) -> nil() r8: mark(s(X)) -> s(mark(X)) r9: mark(cons(X1,X2)) -> cons(mark(X1),X2) r10: a__first(X1,X2) -> first(X1,X2) r11: 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 + 3 first_A(x1,x2) = max{x1, x2 + 1} precedence: mark# = first partial status: pi(mark#) = [] pi(first) = [2] The next rules are strictly ordered: p2 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: mark#(first(X1,X2)) -> mark#(X1) and R consists of: r1: a__first(|0|(),X) -> nil() r2: a__first(s(X),cons(Y,Z)) -> cons(mark(Y),first(X,Z)) r3: a__from(X) -> cons(mark(X),from(s(X))) r4: mark(first(X1,X2)) -> a__first(mark(X1),mark(X2)) r5: mark(from(X)) -> a__from(mark(X)) r6: mark(|0|()) -> |0|() r7: mark(nil()) -> nil() r8: mark(s(X)) -> s(mark(X)) r9: mark(cons(X1,X2)) -> cons(mark(X1),X2) r10: a__first(X1,X2) -> first(X1,X2) r11: 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#(first(X1,X2)) -> mark#(X1) and R consists of: r1: a__first(|0|(),X) -> nil() r2: a__first(s(X),cons(Y,Z)) -> cons(mark(Y),first(X,Z)) r3: a__from(X) -> cons(mark(X),from(s(X))) r4: mark(first(X1,X2)) -> a__first(mark(X1),mark(X2)) r5: mark(from(X)) -> a__from(mark(X)) r6: mark(|0|()) -> |0|() r7: mark(nil()) -> nil() r8: mark(s(X)) -> s(mark(X)) r9: mark(cons(X1,X2)) -> cons(mark(X1),X2) r10: a__first(X1,X2) -> first(X1,X2) r11: 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 first_A(x1,x2) = max{x1 + 1, x2 + 1} precedence: mark# = first partial status: pi(mark#) = [] pi(first) = [2] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.