YES We show the termination of the TRS R: app(app(minus(),x),|0|()) -> x app(app(minus(),app(s(),x)),app(s(),y)) -> app(app(minus(),x),y) app(f(),|0|()) -> app(s(),|0|()) app(f(),app(s(),x)) -> app(app(minus(),app(s(),x)),app(g(),app(f(),x))) app(g(),|0|()) -> |0|() app(g(),app(s(),x)) -> app(app(minus(),app(s(),x)),app(f(),app(g(),x))) 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(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(g_0(),y) -> g_1(y) app(map_0(),y) -> map_1(y) app(map_1(x1),y) -> map_2(x1,y) app(minus_0(),y) -> minus_1(y) app(minus_1(x1),y) -> minus_2(x1,y) app(s_0(),y) -> s_1(y) minus_2(x,|0|_0()) -> x minus_2(s_1(x),s_1(y)) -> minus_2(x,y) f_1(|0|_0()) -> s_1(|0|_0()) f_1(s_1(x)) -> minus_2(s_1(x),g_1(f_1(x))) g_1(|0|_0()) -> |0|_0() g_1(s_1(x)) -> minus_2(s_1(x),f_1(g_1(x))) 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_0(),y) -> f_1#(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#(g_0(),y) -> g_1#(y) p5: app#(map_1(x1),y) -> map_2#(x1,y) p6: app#(minus_1(x1),y) -> minus_2#(x1,y) p7: minus_2#(s_1(x),s_1(y)) -> minus_2#(x,y) p8: f_1#(s_1(x)) -> minus_2#(s_1(x),g_1(f_1(x))) p9: f_1#(s_1(x)) -> g_1#(f_1(x)) p10: f_1#(s_1(x)) -> f_1#(x) p11: g_1#(s_1(x)) -> minus_2#(s_1(x),f_1(g_1(x))) p12: g_1#(s_1(x)) -> f_1#(g_1(x)) p13: g_1#(s_1(x)) -> g_1#(x) p14: map_2#(|fun|,cons_2(x,xs)) -> app#(|fun|,x) p15: map_2#(|fun|,cons_2(x,xs)) -> map_2#(|fun|,xs) p16: filter_2#(|fun|,cons_2(x,xs)) -> filter2_4#(app(|fun|,x),|fun|,x,xs) p17: filter_2#(|fun|,cons_2(x,xs)) -> app#(|fun|,x) p18: filter2_4#(true_0(),|fun|,x,xs) -> filter_2#(|fun|,xs) p19: 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(filter_0(),y) -> filter_1(y) r5: app(filter_1(x1),y) -> filter_2(x1,y) r6: app(filter2_0(),y) -> filter2_1(y) r7: app(filter2_1(x1),y) -> filter2_2(x1,y) r8: app(filter2_2(x1,x2),y) -> filter2_3(x1,x2,y) r9: app(filter2_3(x1,x2,x3),y) -> filter2_4(x1,x2,x3,y) r10: app(g_0(),y) -> g_1(y) r11: app(map_0(),y) -> map_1(y) r12: app(map_1(x1),y) -> map_2(x1,y) r13: app(minus_0(),y) -> minus_1(y) r14: app(minus_1(x1),y) -> minus_2(x1,y) r15: app(s_0(),y) -> s_1(y) r16: minus_2(x,|0|_0()) -> x r17: minus_2(s_1(x),s_1(y)) -> minus_2(x,y) r18: f_1(|0|_0()) -> s_1(|0|_0()) r19: f_1(s_1(x)) -> minus_2(s_1(x),g_1(f_1(x))) r20: g_1(|0|_0()) -> |0|_0() r21: g_1(s_1(x)) -> minus_2(s_1(x),f_1(g_1(x))) r22: map_2(|fun|,nil_0()) -> nil_0() r23: map_2(|fun|,cons_2(x,xs)) -> cons_2(app(|fun|,x),map_2(|fun|,xs)) r24: filter_2(|fun|,nil_0()) -> nil_0() r25: filter_2(|fun|,cons_2(x,xs)) -> filter2_4(app(|fun|,x),|fun|,x,xs) r26: filter2_4(true_0(),|fun|,x,xs) -> cons_2(x,filter_2(|fun|,xs)) r27: filter2_4(false_0(),|fun|,x,xs) -> filter_2(|fun|,xs) The estimated dependency graph contains the following SCCs: {p2, p3, p5, p14, p15, p16, p17, p18, p19} {p9, p10, p12, p13} {p7} -- 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(filter_0(),y) -> filter_1(y) r5: app(filter_1(x1),y) -> filter_2(x1,y) r6: app(filter2_0(),y) -> filter2_1(y) r7: app(filter2_1(x1),y) -> filter2_2(x1,y) r8: app(filter2_2(x1,x2),y) -> filter2_3(x1,x2,y) r9: app(filter2_3(x1,x2,x3),y) -> filter2_4(x1,x2,x3,y) r10: app(g_0(),y) -> g_1(y) r11: app(map_0(),y) -> map_1(y) r12: app(map_1(x1),y) -> map_2(x1,y) r13: app(minus_0(),y) -> minus_1(y) r14: app(minus_1(x1),y) -> minus_2(x1,y) r15: app(s_0(),y) -> s_1(y) r16: minus_2(x,|0|_0()) -> x r17: minus_2(s_1(x),s_1(y)) -> minus_2(x,y) r18: f_1(|0|_0()) -> s_1(|0|_0()) r19: f_1(s_1(x)) -> minus_2(s_1(x),g_1(f_1(x))) r20: g_1(|0|_0()) -> |0|_0() r21: g_1(s_1(x)) -> minus_2(s_1(x),f_1(g_1(x))) r22: map_2(|fun|,nil_0()) -> nil_0() r23: map_2(|fun|,cons_2(x,xs)) -> cons_2(app(|fun|,x),map_2(|fun|,xs)) r24: filter_2(|fun|,nil_0()) -> nil_0() r25: filter_2(|fun|,cons_2(x,xs)) -> filter2_4(app(|fun|,x),|fun|,x,xs) r26: filter2_4(true_0(),|fun|,x,xs) -> cons_2(x,filter_2(|fun|,xs)) r27: filter2_4(false_0(),|fun|,x,xs) -> filter_2(|fun|,xs) The set of usable rules consists of r24 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: map_2#_A(x1,x2) = x1 + x2 + 10 cons_2_A(x1,x2) = x1 + x2 + 7 app#_A(x1,x2) = x1 + x2 + 5 map_1_A(x1) = x1 + 9 filter2_3_A(x1,x2,x3) = x1 + x2 + x3 + 4 filter2_4#_A(x1,x2,x3,x4) = x2 + x4 + 8 false_0_A() = 1 filter_2#_A(x1,x2) = x1 + x2 + 3 filter_1_A(x1) = x1 + 2 app_A(x1,x2) = x1 + x2 + 4 true_0_A() = 4 filter_2_A(x1,x2) = x1 + x2 + 5 nil_0_A() = 1 base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: map_2#_A(x1,x2) = x1 + x2 cons_2_A(x1,x2) = x1 + x2 + 5 app#_A(x1,x2) = x1 + x2 map_1_A(x1) = x1 + 3 filter2_3_A(x1,x2,x3) = x1 + x2 + x3 + 7 filter2_4#_A(x1,x2,x3,x4) = x2 + x4 + 3 false_0_A() = 1 filter_2#_A(x1,x2) = x1 + x2 + 3 filter_1_A(x1) = x1 + 3 app_A(x1,x2) = x1 + x2 + 1 true_0_A() = 1 filter_2_A(x1,x2) = x1 + x2 + 10 nil_0_A() = 13 map_2#!_A(x1,x2) = x2 + 2 cons_2!_A(x1,x2) = x1 + x2 app#!_A(x1,x2) = x1 + 8 map_1!_A(x1) = 1 filter2_3!_A(x1,x2,x3) = 7 filter2_4#!_A(x1,x2,x3,x4) = x2 + x3 + 8 false_0!_A() = 0 filter_2#!_A(x1,x2) = x2 + 12 filter_1!_A(x1) = 13 app!_A(x1,x2) = 6 true_0!_A() = 0 filter_2!_A(x1,x2) = x2 + 1 nil_0!_A() = 21 partial status: pi(map_2#) = [] pi(cons_2) = [2] pi(app#) = [] pi(map_1) = [1] pi(filter2_3) = [3] pi(filter2_4#) = [] pi(false_0) = [] pi(filter_2#) = [] pi(filter_1) = [] pi(app) = [] pi(true_0) = [] pi(filter_2) = [] pi(nil_0) = [] 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: g_1#(s_1(x)) -> f_1#(g_1(x)) p2: f_1#(s_1(x)) -> f_1#(x) p3: f_1#(s_1(x)) -> g_1#(f_1(x)) p4: g_1#(s_1(x)) -> g_1#(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(filter_0(),y) -> filter_1(y) r5: app(filter_1(x1),y) -> filter_2(x1,y) r6: app(filter2_0(),y) -> filter2_1(y) r7: app(filter2_1(x1),y) -> filter2_2(x1,y) r8: app(filter2_2(x1,x2),y) -> filter2_3(x1,x2,y) r9: app(filter2_3(x1,x2,x3),y) -> filter2_4(x1,x2,x3,y) r10: app(g_0(),y) -> g_1(y) r11: app(map_0(),y) -> map_1(y) r12: app(map_1(x1),y) -> map_2(x1,y) r13: app(minus_0(),y) -> minus_1(y) r14: app(minus_1(x1),y) -> minus_2(x1,y) r15: app(s_0(),y) -> s_1(y) r16: minus_2(x,|0|_0()) -> x r17: minus_2(s_1(x),s_1(y)) -> minus_2(x,y) r18: f_1(|0|_0()) -> s_1(|0|_0()) r19: f_1(s_1(x)) -> minus_2(s_1(x),g_1(f_1(x))) r20: g_1(|0|_0()) -> |0|_0() r21: g_1(s_1(x)) -> minus_2(s_1(x),f_1(g_1(x))) r22: map_2(|fun|,nil_0()) -> nil_0() r23: map_2(|fun|,cons_2(x,xs)) -> cons_2(app(|fun|,x),map_2(|fun|,xs)) r24: filter_2(|fun|,nil_0()) -> nil_0() r25: filter_2(|fun|,cons_2(x,xs)) -> filter2_4(app(|fun|,x),|fun|,x,xs) r26: filter2_4(true_0(),|fun|,x,xs) -> cons_2(x,filter_2(|fun|,xs)) r27: filter2_4(false_0(),|fun|,x,xs) -> filter_2(|fun|,xs) The set of usable rules consists of r16, r17, r18, r19, r20, r21, r24 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: g_1#_A(x1) = x1 s_1_A(x1) = x1 + 7 f_1#_A(x1) = x1 + 1 g_1_A(x1) = x1 + 5 f_1_A(x1) = x1 + 7 minus_2_A(x1,x2) = x1 + 4 |0|_0_A() = 1 filter_2_A(x1,x2) = x1 + x2 + 5 nil_0_A() = 1 base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: g_1#_A(x1) = x1 s_1_A(x1) = x1 + 10 f_1#_A(x1) = x1 g_1_A(x1) = x1 + 5 f_1_A(x1) = x1 + 10 minus_2_A(x1,x2) = x1 + 5 |0|_0_A() = 1 filter_2_A(x1,x2) = x2 + 10 nil_0_A() = 6 g_1#!_A(x1) = 10 s_1!_A(x1) = 11 f_1#!_A(x1) = x1 + 4 g_1!_A(x1) = 9 f_1!_A(x1) = x1 + 13 minus_2!_A(x1,x2) = 8 |0|_0!_A() = 0 filter_2!_A(x1,x2) = x2 + 3 nil_0!_A() = 10 partial status: pi(g_1#) = [] pi(s_1) = [1] pi(f_1#) = [1] pi(g_1) = [1] pi(f_1) = [1] pi(minus_2) = [1] pi(|0|_0) = [] pi(filter_2) = [] pi(nil_0) = [] The following rules are removed: p1, p2, p3, p4 Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: minus_2#(s_1(x),s_1(y)) -> minus_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(f_0(),y) -> f_1(y) r4: app(filter_0(),y) -> filter_1(y) r5: app(filter_1(x1),y) -> filter_2(x1,y) r6: app(filter2_0(),y) -> filter2_1(y) r7: app(filter2_1(x1),y) -> filter2_2(x1,y) r8: app(filter2_2(x1,x2),y) -> filter2_3(x1,x2,y) r9: app(filter2_3(x1,x2,x3),y) -> filter2_4(x1,x2,x3,y) r10: app(g_0(),y) -> g_1(y) r11: app(map_0(),y) -> map_1(y) r12: app(map_1(x1),y) -> map_2(x1,y) r13: app(minus_0(),y) -> minus_1(y) r14: app(minus_1(x1),y) -> minus_2(x1,y) r15: app(s_0(),y) -> s_1(y) r16: minus_2(x,|0|_0()) -> x r17: minus_2(s_1(x),s_1(y)) -> minus_2(x,y) r18: f_1(|0|_0()) -> s_1(|0|_0()) r19: f_1(s_1(x)) -> minus_2(s_1(x),g_1(f_1(x))) r20: g_1(|0|_0()) -> |0|_0() r21: g_1(s_1(x)) -> minus_2(s_1(x),f_1(g_1(x))) r22: map_2(|fun|,nil_0()) -> nil_0() r23: map_2(|fun|,cons_2(x,xs)) -> cons_2(app(|fun|,x),map_2(|fun|,xs)) r24: filter_2(|fun|,nil_0()) -> nil_0() r25: filter_2(|fun|,cons_2(x,xs)) -> filter2_4(app(|fun|,x),|fun|,x,xs) r26: filter2_4(true_0(),|fun|,x,xs) -> cons_2(x,filter_2(|fun|,xs)) r27: filter2_4(false_0(),|fun|,x,xs) -> filter_2(|fun|,xs) The set of usable rules consists of r16, r17, r24 Take the reduction pair: generalized weighted path order (>=MG, >G) base order 1: matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: minus_2#_A(x1,x2) = x1 + x2 + 3 s_1_A(x1) = x1 + 2 minus_2_A(x1,x2) = x1 + x2 + 5 |0|_0_A() = 4 filter_2_A(x1,x2) = x1 + x2 + 5 nil_0_A() = 1 base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): matrix interpretation with standard point-wise order: carrier: N^1 order: standard order interpretations: minus_2#_A(x1,x2) = x1 + x2 s_1_A(x1) = x1 + 6 minus_2_A(x1,x2) = x1 + 5 |0|_0_A() = 4 filter_2_A(x1,x2) = x2 + 10 nil_0_A() = 6 minus_2#!_A(x1,x2) = x1 + x2 + 10 s_1!_A(x1) = 9 minus_2!_A(x1,x2) = x1 + 4 |0|_0!_A() = 8 filter_2!_A(x1,x2) = x2 + 4 nil_0!_A() = 0 partial status: pi(minus_2#) = [] pi(s_1) = [1] pi(minus_2) = [2] pi(|0|_0) = [] pi(filter_2) = [] pi(nil_0) = [] The following rules are removed: p1 Then no dependency pair remains.