YES We show the termination of the TRS R: app(app(plus(),|0|()),y) -> y app(app(plus(),app(s(),x)),y) -> app(s(),app(app(plus(),x),y)) app(app(times(),|0|()),y) -> |0|() app(app(times(),app(s(),x)),y) -> app(app(plus(),app(app(times(),x),y)),y) app(inc(),xs) -> app(app(map(),app(plus(),app(s(),|0|()))),xs) app(double(),xs) -> app(app(map(),app(times(),app(s(),app(s(),|0|())))),xs) app(app(map(),f),nil()) -> nil() app(app(map(),f),app(app(cons(),x),xs)) -> app(app(cons(),app(f,x)),app(app(map(),f),xs)) Instead we prove termination of the uncurried system: app(cons_0(),y) -> cons_1(y) app(cons_1(x1),y) -> cons_2(x1,y) app(double_0(),y) -> double_1(y) app(inc_0(),y) -> inc_1(y) app(map_0(),y) -> map_1(y) app(map_1(x1),y) -> map_2(x1,y) app(plus_0(),y) -> plus_1(y) app(plus_1(x1),y) -> plus_2(x1,y) app(s_0(),y) -> s_1(y) app(times_0(),y) -> times_1(y) app(times_1(x1),y) -> times_2(x1,y) plus_2(|0|_0(),y) -> y plus_2(s_1(x),y) -> s_1(plus_2(x,y)) times_2(|0|_0(),y) -> |0|_0() times_2(s_1(x),y) -> plus_2(times_2(x,y),y) inc_1(xs) -> map_2(plus_1(s_1(|0|_0())),xs) double_1(xs) -> map_2(times_1(s_1(s_1(|0|_0()))),xs) map_2(f,nil_0()) -> nil_0() map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: app#(double_0(),y) -> double_1#(y) p2: app#(inc_0(),y) -> inc_1#(y) p3: app#(map_1(x1),y) -> map_2#(x1,y) p4: app#(plus_1(x1),y) -> plus_2#(x1,y) p5: app#(times_1(x1),y) -> times_2#(x1,y) p6: plus_2#(s_1(x),y) -> plus_2#(x,y) p7: times_2#(s_1(x),y) -> plus_2#(times_2(x,y),y) p8: times_2#(s_1(x),y) -> times_2#(x,y) p9: inc_1#(xs) -> map_2#(plus_1(s_1(|0|_0())),xs) p10: double_1#(xs) -> map_2#(times_1(s_1(s_1(|0|_0()))),xs) p11: map_2#(f,cons_2(x,xs)) -> app#(f,x) p12: map_2#(f,cons_2(x,xs)) -> map_2#(f,xs) and R consists of: r1: app(cons_0(),y) -> cons_1(y) r2: app(cons_1(x1),y) -> cons_2(x1,y) r3: app(double_0(),y) -> double_1(y) r4: app(inc_0(),y) -> inc_1(y) r5: app(map_0(),y) -> map_1(y) r6: app(map_1(x1),y) -> map_2(x1,y) r7: app(plus_0(),y) -> plus_1(y) r8: app(plus_1(x1),y) -> plus_2(x1,y) r9: app(s_0(),y) -> s_1(y) r10: app(times_0(),y) -> times_1(y) r11: app(times_1(x1),y) -> times_2(x1,y) r12: plus_2(|0|_0(),y) -> y r13: plus_2(s_1(x),y) -> s_1(plus_2(x,y)) r14: times_2(|0|_0(),y) -> |0|_0() r15: times_2(s_1(x),y) -> plus_2(times_2(x,y),y) r16: inc_1(xs) -> map_2(plus_1(s_1(|0|_0())),xs) r17: double_1(xs) -> map_2(times_1(s_1(s_1(|0|_0()))),xs) r18: map_2(f,nil_0()) -> nil_0() r19: map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) The estimated dependency graph contains the following SCCs: {p1, p2, p3, p9, p10, p11, p12} {p8} {p6} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: app#(double_0(),y) -> double_1#(y) p2: double_1#(xs) -> map_2#(times_1(s_1(s_1(|0|_0()))),xs) p3: map_2#(f,cons_2(x,xs)) -> map_2#(f,xs) p4: map_2#(f,cons_2(x,xs)) -> app#(f,x) p5: app#(map_1(x1),y) -> map_2#(x1,y) p6: app#(inc_0(),y) -> inc_1#(y) p7: inc_1#(xs) -> map_2#(plus_1(s_1(|0|_0())),xs) and R consists of: r1: app(cons_0(),y) -> cons_1(y) r2: app(cons_1(x1),y) -> cons_2(x1,y) r3: app(double_0(),y) -> double_1(y) r4: app(inc_0(),y) -> inc_1(y) r5: app(map_0(),y) -> map_1(y) r6: app(map_1(x1),y) -> map_2(x1,y) r7: app(plus_0(),y) -> plus_1(y) r8: app(plus_1(x1),y) -> plus_2(x1,y) r9: app(s_0(),y) -> s_1(y) r10: app(times_0(),y) -> times_1(y) r11: app(times_1(x1),y) -> times_2(x1,y) r12: plus_2(|0|_0(),y) -> y r13: plus_2(s_1(x),y) -> s_1(plus_2(x,y)) r14: times_2(|0|_0(),y) -> |0|_0() r15: times_2(s_1(x),y) -> plus_2(times_2(x,y),y) r16: inc_1(xs) -> map_2(plus_1(s_1(|0|_0())),xs) r17: double_1(xs) -> map_2(times_1(s_1(s_1(|0|_0()))),xs) r18: map_2(f,nil_0()) -> nil_0() r19: map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) The set of usable rules consists of (no rules) Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: trivial reduction triple (T x T, T x T, Φ) base order 2: lexicographic combination of reduction triples: 1. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: app#_A(x1,x2) = max{0, x1 - 62, x2 - 10} double_0_A = 0 double_1#_A(x1) = max{0, x1 - 47} map_2#_A(x1,x2) = max{0, x1 - 61, x2 - 57} times_1_A(x1) = x1 + 41 s_1_A(x1) = max{8, x1 - 16} |0|_0_A = 6 cons_2_A(x1,x2) = max{x1 + 47, x2 + 43} map_1_A(x1) = max{61, x1 + 1} inc_0_A = 61 inc_1#_A(x1) = max{0, x1 - 57} plus_1_A(x1) = x1 + 52 app#!_A(x1,x2) = max{5, x1 - 64, x2 - 3} double_0!_A = 6 double_1#!_A(x1) = max{5, x1 - 50} map_2#!_A(x1,x2) = max{5, x1 - 64, x2 - 50} times_1!_A(x1) = max{6, x1 - 63} s_1!_A(x1) = max{4, x1 - 59} |0|_0!_A = 0 cons_2!_A(x1,x2) = max{1, x1 - 63, x2 - 60} map_1!_A(x1) = max{3, x1 - 63} inc_0!_A = 6 inc_1#!_A(x1) = max{5, x1 - 3} plus_1!_A(x1) = x1 + 8 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: app#_A(x1,x2) = max{0, x1 - 6, x2 - 68} double_0_A = 5 double_1#_A(x1) = max{0, x1 - 68} map_2#_A(x1,x2) = max{0, x1 - 5, x2 - 82} times_1_A(x1) = max{4, x1 - 10} s_1_A(x1) = max{14, x1 - 34} |0|_0_A = 16 cons_2_A(x1,x2) = max{x1 + 68, x2 + 81} map_1_A(x1) = x1 + 5 inc_0_A = 5 inc_1#_A(x1) = max{0, x1 - 68} plus_1_A(x1) = max{2, x1 - 12} app#!_A(x1,x2) = max{12, x1 - 6, x2 - 2} double_0!_A = 1 double_1#!_A(x1) = max{7, x1 - 68} map_2#!_A(x1,x2) = max{6, x1 - 5, x2 - 69} times_1!_A(x1) = max{13, x1 - 1} s_1!_A(x1) = max{7, x1 - 145} |0|_0!_A = 11 cons_2!_A(x1,x2) = max{3, x1 - 85, x2 - 83} map_1!_A(x1) = max{5, x1 - 6} inc_0!_A = 9 inc_1#!_A(x1) = max{11, x1 - 2} plus_1!_A(x1) = max{9, x1 - 143} partial status: pi(app#) = [2] pi(double_0) = [] pi(double_1#) = [1] pi(map_2#) = [2] pi(times_1) = [1] pi(s_1) = [] pi(|0|_0) = [] pi(cons_2) = [1, 2] pi(map_1) = [1] pi(inc_0) = [] pi(inc_1#) = [1] pi(plus_1) = [1] The following rules are removed: p1, p2, p5, p7 -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: map_2#(f,cons_2(x,xs)) -> map_2#(f,xs) p2: map_2#(f,cons_2(x,xs)) -> app#(f,x) p3: app#(inc_0(),y) -> inc_1#(y) and R consists of: r1: app(cons_0(),y) -> cons_1(y) r2: app(cons_1(x1),y) -> cons_2(x1,y) r3: app(double_0(),y) -> double_1(y) r4: app(inc_0(),y) -> inc_1(y) r5: app(map_0(),y) -> map_1(y) r6: app(map_1(x1),y) -> map_2(x1,y) r7: app(plus_0(),y) -> plus_1(y) r8: app(plus_1(x1),y) -> plus_2(x1,y) r9: app(s_0(),y) -> s_1(y) r10: app(times_0(),y) -> times_1(y) r11: app(times_1(x1),y) -> times_2(x1,y) r12: plus_2(|0|_0(),y) -> y r13: plus_2(s_1(x),y) -> s_1(plus_2(x,y)) r14: times_2(|0|_0(),y) -> |0|_0() r15: times_2(s_1(x),y) -> plus_2(times_2(x,y),y) r16: inc_1(xs) -> map_2(plus_1(s_1(|0|_0())),xs) r17: double_1(xs) -> map_2(times_1(s_1(s_1(|0|_0()))),xs) r18: map_2(f,nil_0()) -> nil_0() r19: map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) The estimated dependency graph contains the following SCCs: {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: map_2#(f,cons_2(x,xs)) -> map_2#(f,xs) and R consists of: r1: app(cons_0(),y) -> cons_1(y) r2: app(cons_1(x1),y) -> cons_2(x1,y) r3: app(double_0(),y) -> double_1(y) r4: app(inc_0(),y) -> inc_1(y) r5: app(map_0(),y) -> map_1(y) r6: app(map_1(x1),y) -> map_2(x1,y) r7: app(plus_0(),y) -> plus_1(y) r8: app(plus_1(x1),y) -> plus_2(x1,y) r9: app(s_0(),y) -> s_1(y) r10: app(times_0(),y) -> times_1(y) r11: app(times_1(x1),y) -> times_2(x1,y) r12: plus_2(|0|_0(),y) -> y r13: plus_2(s_1(x),y) -> s_1(plus_2(x,y)) r14: times_2(|0|_0(),y) -> |0|_0() r15: times_2(s_1(x),y) -> plus_2(times_2(x,y),y) r16: inc_1(xs) -> map_2(plus_1(s_1(|0|_0())),xs) r17: double_1(xs) -> map_2(times_1(s_1(s_1(|0|_0()))),xs) r18: map_2(f,nil_0()) -> nil_0() r19: map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) The set of usable rules consists of (no rules) Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: trivial reduction triple (T x T, T x T, Φ) base order 2: lexicographic combination of reduction triples: 1. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: map_2#_A(x1,x2) = 0 cons_2_A(x1,x2) = max{4, x1 - 11, x2 - 11} map_2#!_A(x1,x2) = 1 cons_2!_A(x1,x2) = max{3, x1 - 18, x2 - 22} 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: map_2#_A(x1,x2) = 0 cons_2_A(x1,x2) = max{34, x1 - 5, x2 - 34} map_2#!_A(x1,x2) = max{2, x1 - 1, x2 - 35} cons_2!_A(x1,x2) = max{1, x1 - 7, x2 - 39} partial status: pi(map_2#) = [2] pi(cons_2) = [1, 2] The following rules are removed: p1 Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: times_2#(s_1(x),y) -> times_2#(x,y) and R consists of: r1: app(cons_0(),y) -> cons_1(y) r2: app(cons_1(x1),y) -> cons_2(x1,y) r3: app(double_0(),y) -> double_1(y) r4: app(inc_0(),y) -> inc_1(y) r5: app(map_0(),y) -> map_1(y) r6: app(map_1(x1),y) -> map_2(x1,y) r7: app(plus_0(),y) -> plus_1(y) r8: app(plus_1(x1),y) -> plus_2(x1,y) r9: app(s_0(),y) -> s_1(y) r10: app(times_0(),y) -> times_1(y) r11: app(times_1(x1),y) -> times_2(x1,y) r12: plus_2(|0|_0(),y) -> y r13: plus_2(s_1(x),y) -> s_1(plus_2(x,y)) r14: times_2(|0|_0(),y) -> |0|_0() r15: times_2(s_1(x),y) -> plus_2(times_2(x,y),y) r16: inc_1(xs) -> map_2(plus_1(s_1(|0|_0())),xs) r17: double_1(xs) -> map_2(times_1(s_1(s_1(|0|_0()))),xs) r18: map_2(f,nil_0()) -> nil_0() r19: map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) The set of usable rules consists of (no rules) Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: trivial reduction triple (T x T, T x T, Φ) base order 2: lexicographic combination of reduction triples: 1. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: times_2#_A(x1,x2) = 0 s_1_A(x1) = max{5, x1 - 8} times_2#!_A(x1,x2) = 1 s_1!_A(x1) = max{5, x1 - 28} 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: times_2#_A(x1,x2) = 0 s_1_A(x1) = max{8, x1 - 10} times_2#!_A(x1,x2) = max{7, x1 - 25, x2 - 1} s_1!_A(x1) = max{6, x1 - 25} partial status: pi(times_2#) = [1] pi(s_1) = [1] The following rules are removed: p1 Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: plus_2#(s_1(x),y) -> plus_2#(x,y) and R consists of: r1: app(cons_0(),y) -> cons_1(y) r2: app(cons_1(x1),y) -> cons_2(x1,y) r3: app(double_0(),y) -> double_1(y) r4: app(inc_0(),y) -> inc_1(y) r5: app(map_0(),y) -> map_1(y) r6: app(map_1(x1),y) -> map_2(x1,y) r7: app(plus_0(),y) -> plus_1(y) r8: app(plus_1(x1),y) -> plus_2(x1,y) r9: app(s_0(),y) -> s_1(y) r10: app(times_0(),y) -> times_1(y) r11: app(times_1(x1),y) -> times_2(x1,y) r12: plus_2(|0|_0(),y) -> y r13: plus_2(s_1(x),y) -> s_1(plus_2(x,y)) r14: times_2(|0|_0(),y) -> |0|_0() r15: times_2(s_1(x),y) -> plus_2(times_2(x,y),y) r16: inc_1(xs) -> map_2(plus_1(s_1(|0|_0())),xs) r17: double_1(xs) -> map_2(times_1(s_1(s_1(|0|_0()))),xs) r18: map_2(f,nil_0()) -> nil_0() r19: map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) The set of usable rules consists of (no rules) Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: trivial reduction triple (T x T, T x T, Φ) base order 2: lexicographic combination of reduction triples: 1. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: plus_2#_A(x1,x2) = 0 s_1_A(x1) = max{4, x1 - 6} plus_2#!_A(x1,x2) = max{0, x1 - 9} s_1!_A(x1) = max{7, x1 - 8} 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: plus_2#_A(x1,x2) = 0 s_1_A(x1) = max{4, x1 - 15} plus_2#!_A(x1,x2) = max{4, x1 - 40, x2 - 1} s_1!_A(x1) = max{3, x1 - 41} partial status: pi(plus_2#) = [1] pi(s_1) = [1] The following rules are removed: p1 Then no dependency pair remains.