YES We show the termination of the TRS R: app(app(app(f(),|0|()),|1|()),x) -> app(app(app(f(),app(s(),x)),x),x) app(app(app(f(),x),y),app(s(),z)) -> app(s(),app(app(app(f(),|0|()),|1|()),z)) app(app(map(),|fun|),nil()) -> nil() app(app(map(),|fun|),app(app(cons(),x),xs)) -> app(app(cons(),app(|fun|,x)),app(app(map(),|fun|),xs)) app(app(filter(),|fun|),nil()) -> nil() app(app(filter(),|fun|),app(app(cons(),x),xs)) -> app(app(app(app(filter2(),app(|fun|,x)),|fun|),x),xs) app(app(app(app(filter2(),true()),|fun|),x),xs) -> app(app(cons(),x),app(app(filter(),|fun|),xs)) app(app(app(app(filter2(),false()),|fun|),x),xs) -> app(app(filter(),|fun|),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(f_0(),y) -> f_1(y) app(f_1(x1),y) -> f_2(x1,y) app(f_2(x1,x2),y) -> f_3(x1,x2,y) app(filter_0(),y) -> filter_1(y) app(filter_1(x1),y) -> filter_2(x1,y) app(filter2_0(),y) -> filter2_1(y) app(filter2_1(x1),y) -> filter2_2(x1,y) app(filter2_2(x1,x2),y) -> filter2_3(x1,x2,y) app(filter2_3(x1,x2,x3),y) -> filter2_4(x1,x2,x3,y) app(map_0(),y) -> map_1(y) app(map_1(x1),y) -> map_2(x1,y) app(s_0(),y) -> s_1(y) f_3(|0|_0(),|1|_0(),x) -> f_3(s_1(x),x,x) f_3(x,y,s_1(z)) -> s_1(f_3(|0|_0(),|1|_0(),z)) map_2(|fun|,nil_0()) -> nil_0() map_2(|fun|,cons_2(x,xs)) -> cons_2(app(|fun|,x),map_2(|fun|,xs)) filter_2(|fun|,nil_0()) -> nil_0() filter_2(|fun|,cons_2(x,xs)) -> filter2_4(app(|fun|,x),|fun|,x,xs) filter2_4(true_0(),|fun|,x,xs) -> cons_2(x,filter_2(|fun|,xs)) filter2_4(false_0(),|fun|,x,xs) -> filter_2(|fun|,xs) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: app#(f_2(x1,x2),y) -> f_3#(x1,x2,y) p2: app#(filter_1(x1),y) -> filter_2#(x1,y) p3: app#(filter2_3(x1,x2,x3),y) -> filter2_4#(x1,x2,x3,y) p4: app#(map_1(x1),y) -> map_2#(x1,y) p5: f_3#(|0|_0(),|1|_0(),x) -> f_3#(s_1(x),x,x) p6: f_3#(x,y,s_1(z)) -> f_3#(|0|_0(),|1|_0(),z) p7: map_2#(|fun|,cons_2(x,xs)) -> app#(|fun|,x) p8: map_2#(|fun|,cons_2(x,xs)) -> map_2#(|fun|,xs) p9: filter_2#(|fun|,cons_2(x,xs)) -> filter2_4#(app(|fun|,x),|fun|,x,xs) p10: filter_2#(|fun|,cons_2(x,xs)) -> app#(|fun|,x) p11: filter2_4#(true_0(),|fun|,x,xs) -> filter_2#(|fun|,xs) p12: filter2_4#(false_0(),|fun|,x,xs) -> filter_2#(|fun|,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(f_0(),y) -> f_1(y) r4: app(f_1(x1),y) -> f_2(x1,y) r5: app(f_2(x1,x2),y) -> f_3(x1,x2,y) r6: app(filter_0(),y) -> filter_1(y) r7: app(filter_1(x1),y) -> filter_2(x1,y) r8: app(filter2_0(),y) -> filter2_1(y) r9: app(filter2_1(x1),y) -> filter2_2(x1,y) r10: app(filter2_2(x1,x2),y) -> filter2_3(x1,x2,y) r11: app(filter2_3(x1,x2,x3),y) -> filter2_4(x1,x2,x3,y) r12: app(map_0(),y) -> map_1(y) r13: app(map_1(x1),y) -> map_2(x1,y) r14: app(s_0(),y) -> s_1(y) r15: f_3(|0|_0(),|1|_0(),x) -> f_3(s_1(x),x,x) r16: f_3(x,y,s_1(z)) -> s_1(f_3(|0|_0(),|1|_0(),z)) r17: map_2(|fun|,nil_0()) -> nil_0() r18: map_2(|fun|,cons_2(x,xs)) -> cons_2(app(|fun|,x),map_2(|fun|,xs)) r19: filter_2(|fun|,nil_0()) -> nil_0() r20: filter_2(|fun|,cons_2(x,xs)) -> filter2_4(app(|fun|,x),|fun|,x,xs) r21: filter2_4(true_0(),|fun|,x,xs) -> cons_2(x,filter_2(|fun|,xs)) r22: filter2_4(false_0(),|fun|,x,xs) -> filter_2(|fun|,xs) The estimated dependency graph contains the following SCCs: {p2, p3, p4, p7, p8, p9, p10, p11, p12} {p5, p6} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: map_2#(|fun|,cons_2(x,xs)) -> app#(|fun|,x) p2: app#(map_1(x1),y) -> map_2#(x1,y) p3: map_2#(|fun|,cons_2(x,xs)) -> map_2#(|fun|,xs) p4: app#(filter2_3(x1,x2,x3),y) -> filter2_4#(x1,x2,x3,y) p5: filter2_4#(false_0(),|fun|,x,xs) -> filter_2#(|fun|,xs) p6: filter_2#(|fun|,cons_2(x,xs)) -> app#(|fun|,x) p7: app#(filter_1(x1),y) -> filter_2#(x1,y) p8: filter_2#(|fun|,cons_2(x,xs)) -> filter2_4#(app(|fun|,x),|fun|,x,xs) p9: filter2_4#(true_0(),|fun|,x,xs) -> filter_2#(|fun|,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(f_0(),y) -> f_1(y) r4: app(f_1(x1),y) -> f_2(x1,y) r5: app(f_2(x1,x2),y) -> f_3(x1,x2,y) r6: app(filter_0(),y) -> filter_1(y) r7: app(filter_1(x1),y) -> filter_2(x1,y) r8: app(filter2_0(),y) -> filter2_1(y) r9: app(filter2_1(x1),y) -> filter2_2(x1,y) r10: app(filter2_2(x1,x2),y) -> filter2_3(x1,x2,y) r11: app(filter2_3(x1,x2,x3),y) -> filter2_4(x1,x2,x3,y) r12: app(map_0(),y) -> map_1(y) r13: app(map_1(x1),y) -> map_2(x1,y) r14: app(s_0(),y) -> s_1(y) r15: f_3(|0|_0(),|1|_0(),x) -> f_3(s_1(x),x,x) r16: f_3(x,y,s_1(z)) -> s_1(f_3(|0|_0(),|1|_0(),z)) r17: map_2(|fun|,nil_0()) -> nil_0() r18: map_2(|fun|,cons_2(x,xs)) -> cons_2(app(|fun|,x),map_2(|fun|,xs)) r19: filter_2(|fun|,nil_0()) -> nil_0() r20: filter_2(|fun|,cons_2(x,xs)) -> filter2_4(app(|fun|,x),|fun|,x,xs) r21: filter2_4(true_0(),|fun|,x,xs) -> cons_2(x,filter_2(|fun|,xs)) r22: filter2_4(false_0(),|fun|,x,xs) -> filter_2(|fun|,xs) The set of usable rules consists of r17, r19 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) = max{36, x1 + 34} cons_2_A(x1,x2) = x1 + 23 app#_A(x1,x2) = max{36, x1} map_1_A(x1) = max{35, x1 + 34} filter2_3_A(x1,x2,x3) = max{3, x1 - 53, x2, x3} filter2_4#_A(x1,x2,x3,x4) = max{36, x2} false_0_A = 0 filter_2#_A(x1,x2) = max{36, x1} filter_1_A(x1) = max{35, x1 + 33} app_A(x1,x2) = x2 + 13 true_0_A = 59 map_2_A(x1,x2) = max{49, x1 - 10, x2 - 24} nil_0_A = 5 filter_2_A(x1,x2) = max{4, x1 - 119, x2 + 1} map_2#!_A(x1,x2) = 5 cons_2!_A(x1,x2) = max{55, x1 + 9, x2 + 7} app#!_A(x1,x2) = x2 + 8 map_1!_A(x1) = max{6, x1 - 1} filter2_3!_A(x1,x2,x3) = max{4, x2 - 1, x3 - 2} filter2_4#!_A(x1,x2,x3,x4) = x4 + 7 false_0!_A = 11 filter_2#!_A(x1,x2) = max{7, x2 + 1} filter_1!_A(x1) = max{7, x1 + 1} app!_A(x1,x2) = 3 true_0!_A = 1 map_2!_A(x1,x2) = max{57, x1 - 2, x2} nil_0!_A = 15 filter_2!_A(x1,x2) = max{x1 + 16, x2 + 9} 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: map_2#_A(x1,x2) = max{1, x1 - 20, x2 - 5} cons_2_A(x1,x2) = max{4, x1 + 3, x2} app#_A(x1,x2) = max{1, x1 - 27, x2 - 2} map_1_A(x1) = max{8, x1 + 7} filter2_3_A(x1,x2,x3) = max{x1 - 68, x2 + 7, x3 + 26} filter2_4#_A(x1,x2,x3,x4) = max{1, x2 - 20, x3 - 2, x4 - 5} false_0_A = 0 filter_2#_A(x1,x2) = max{1, x1 - 20, x2 - 5} filter_1_A(x1) = max{9, x1 + 7} app_A(x1,x2) = max{0, x1 - 20} true_0_A = 0 map_2_A(x1,x2) = max{30, x1 - 17, x2 - 28} nil_0_A = 30 filter_2_A(x1,x2) = max{6, x1 - 89, x2 + 1} map_2#!_A(x1,x2) = max{16, x1 - 8, x2 - 5} cons_2!_A(x1,x2) = max{15, x1 + 7, x2 + 5} app#!_A(x1,x2) = x2 + 5 map_1!_A(x1) = x1 + 17 filter2_3!_A(x1,x2,x3) = max{0, x1 - 2, x2 - 3, x3 - 1} filter2_4#!_A(x1,x2,x3,x4) = x4 + 4 false_0!_A = 5 filter_2#!_A(x1,x2) = x2 + 3 filter_1!_A(x1) = 1 app!_A(x1,x2) = max{0, x1 - 10, x2 - 19} true_0!_A = 16 map_2!_A(x1,x2) = max{0, x1 - 11, x2 - 22} nil_0!_A = 7 filter_2!_A(x1,x2) = max{6, x1 - 2, x2 - 31} partial status: pi(map_2#) = [2] pi(cons_2) = [1, 2] pi(app#) = [2] pi(map_1) = [1] pi(filter2_3) = [3] pi(filter2_4#) = [4] pi(false_0) = [] pi(filter_2#) = [2] pi(filter_1) = [] pi(app) = [2] pi(true_0) = [] pi(map_2) = [2] pi(nil_0) = [] pi(filter_2) = [] The following rules are removed: p1, p2, p3, p4, p5, p6, p7, p8, p9 Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: f_3#(|0|_0(),|1|_0(),x) -> f_3#(s_1(x),x,x) p2: f_3#(x,y,s_1(z)) -> f_3#(|0|_0(),|1|_0(),z) and R consists of: r1: app(cons_0(),y) -> cons_1(y) r2: app(cons_1(x1),y) -> cons_2(x1,y) r3: app(f_0(),y) -> f_1(y) r4: app(f_1(x1),y) -> f_2(x1,y) r5: app(f_2(x1,x2),y) -> f_3(x1,x2,y) r6: app(filter_0(),y) -> filter_1(y) r7: app(filter_1(x1),y) -> filter_2(x1,y) r8: app(filter2_0(),y) -> filter2_1(y) r9: app(filter2_1(x1),y) -> filter2_2(x1,y) r10: app(filter2_2(x1,x2),y) -> filter2_3(x1,x2,y) r11: app(filter2_3(x1,x2,x3),y) -> filter2_4(x1,x2,x3,y) r12: app(map_0(),y) -> map_1(y) r13: app(map_1(x1),y) -> map_2(x1,y) r14: app(s_0(),y) -> s_1(y) r15: f_3(|0|_0(),|1|_0(),x) -> f_3(s_1(x),x,x) r16: f_3(x,y,s_1(z)) -> s_1(f_3(|0|_0(),|1|_0(),z)) r17: map_2(|fun|,nil_0()) -> nil_0() r18: map_2(|fun|,cons_2(x,xs)) -> cons_2(app(|fun|,x),map_2(|fun|,xs)) r19: filter_2(|fun|,nil_0()) -> nil_0() r20: filter_2(|fun|,cons_2(x,xs)) -> filter2_4(app(|fun|,x),|fun|,x,xs) r21: filter2_4(true_0(),|fun|,x,xs) -> cons_2(x,filter_2(|fun|,xs)) r22: filter2_4(false_0(),|fun|,x,xs) -> filter_2(|fun|,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: f_3#_A(x1,x2,x3) = max{0, x1 - 22, x2 - 22, x3 - 15} |0|_0_A = 21 |1|_0_A = 21 s_1_A(x1) = max{8, x1 + 4} f_3#!_A(x1,x2,x3) = max{2, x1 - 18, x2 - 18, x3 - 9} |0|_0!_A = 1 |1|_0!_A = 1 s_1!_A(x1) = max{4, x1 - 9} 2. marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: f_3#_A(x1,x2,x3) = max{0, x1 - 7, x2 - 8, x3 - 6} |0|_0_A = 6 |1|_0_A = 7 s_1_A(x1) = max{4, x1 + 1} f_3#!_A(x1,x2,x3) = max{4, x1 - 13, x2 - 21, x3 - 10} |0|_0!_A = 1 |1|_0!_A = 3 s_1!_A(x1) = max{4, x1 - 9} partial status: pi(f_3#) = [3] pi(|0|_0) = [] pi(|1|_0) = [] pi(s_1) = [1] The following rules are removed: p2 -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: f_3#(|0|_0(),|1|_0(),x) -> f_3#(s_1(x),x,x) and R consists of: r1: app(cons_0(),y) -> cons_1(y) r2: app(cons_1(x1),y) -> cons_2(x1,y) r3: app(f_0(),y) -> f_1(y) r4: app(f_1(x1),y) -> f_2(x1,y) r5: app(f_2(x1,x2),y) -> f_3(x1,x2,y) r6: app(filter_0(),y) -> filter_1(y) r7: app(filter_1(x1),y) -> filter_2(x1,y) r8: app(filter2_0(),y) -> filter2_1(y) r9: app(filter2_1(x1),y) -> filter2_2(x1,y) r10: app(filter2_2(x1,x2),y) -> filter2_3(x1,x2,y) r11: app(filter2_3(x1,x2,x3),y) -> filter2_4(x1,x2,x3,y) r12: app(map_0(),y) -> map_1(y) r13: app(map_1(x1),y) -> map_2(x1,y) r14: app(s_0(),y) -> s_1(y) r15: f_3(|0|_0(),|1|_0(),x) -> f_3(s_1(x),x,x) r16: f_3(x,y,s_1(z)) -> s_1(f_3(|0|_0(),|1|_0(),z)) r17: map_2(|fun|,nil_0()) -> nil_0() r18: map_2(|fun|,cons_2(x,xs)) -> cons_2(app(|fun|,x),map_2(|fun|,xs)) r19: filter_2(|fun|,nil_0()) -> nil_0() r20: filter_2(|fun|,cons_2(x,xs)) -> filter2_4(app(|fun|,x),|fun|,x,xs) r21: filter2_4(true_0(),|fun|,x,xs) -> cons_2(x,filter_2(|fun|,xs)) r22: filter2_4(false_0(),|fun|,x,xs) -> filter_2(|fun|,xs) The estimated dependency graph contains the following SCCs: (no SCCs)