YES We show the termination of the TRS R: 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)) app(app(minus(),x),|0|()) -> x app(app(minus(),app(s(),x)),app(s(),y)) -> app(app(minus(),x),y) app(app(div(),|0|()),app(s(),y)) -> |0|() app(app(div(),app(s(),x)),app(s(),y)) -> app(s(),app(app(div(),app(app(minus(),x),y)),app(s(),y))) 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(div_0(),y) -> div_1(y) app(div_1(x1),y) -> div_2(x1,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) map_2(f,nil_0()) -> nil_0() map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) minus_2(x,|0|_0()) -> x minus_2(s_1(x),s_1(y)) -> minus_2(x,y) div_2(|0|_0(),s_1(y)) -> |0|_0() div_2(s_1(x),s_1(y)) -> s_1(div_2(minus_2(x,y),s_1(y))) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: app#(div_1(x1),y) -> div_2#(x1,y) p2: app#(map_1(x1),y) -> map_2#(x1,y) p3: app#(minus_1(x1),y) -> minus_2#(x1,y) p4: map_2#(f,cons_2(x,xs)) -> app#(f,x) p5: map_2#(f,cons_2(x,xs)) -> map_2#(f,xs) p6: minus_2#(s_1(x),s_1(y)) -> minus_2#(x,y) p7: div_2#(s_1(x),s_1(y)) -> div_2#(minus_2(x,y),s_1(y)) p8: div_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(div_0(),y) -> div_1(y) r4: app(div_1(x1),y) -> div_2(x1,y) r5: app(map_0(),y) -> map_1(y) r6: app(map_1(x1),y) -> map_2(x1,y) r7: app(minus_0(),y) -> minus_1(y) r8: app(minus_1(x1),y) -> minus_2(x1,y) r9: app(s_0(),y) -> s_1(y) r10: map_2(f,nil_0()) -> nil_0() r11: map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) r12: minus_2(x,|0|_0()) -> x r13: minus_2(s_1(x),s_1(y)) -> minus_2(x,y) r14: div_2(|0|_0(),s_1(y)) -> |0|_0() r15: div_2(s_1(x),s_1(y)) -> s_1(div_2(minus_2(x,y),s_1(y))) The estimated dependency graph contains the following SCCs: {p2, p4, p5} {p7} {p6} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: map_2#(f,cons_2(x,xs)) -> app#(f,x) p2: app#(map_1(x1),y) -> map_2#(x1,y) p3: 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(div_0(),y) -> div_1(y) r4: app(div_1(x1),y) -> div_2(x1,y) r5: app(map_0(),y) -> map_1(y) r6: app(map_1(x1),y) -> map_2(x1,y) r7: app(minus_0(),y) -> minus_1(y) r8: app(minus_1(x1),y) -> minus_2(x1,y) r9: app(s_0(),y) -> s_1(y) r10: map_2(f,nil_0()) -> nil_0() r11: map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) r12: minus_2(x,|0|_0()) -> x r13: minus_2(s_1(x),s_1(y)) -> minus_2(x,y) r14: div_2(|0|_0(),s_1(y)) -> |0|_0() r15: div_2(s_1(x),s_1(y)) -> s_1(div_2(minus_2(x,y),s_1(y))) The set of usable rules consists of (no rules) 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 + 5 cons_2_A(x1,x2) = x1 + x2 + 4 app#_A(x1,x2) = x1 + x2 + 5 map_1_A(x1) = x1 + 2 base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: map_2#_A(x1,x2) = max{0, x1 - 3, x2 - 16} cons_2_A(x1,x2) = max{x1 + 2, x2 + 15} app#_A(x1,x2) = max{0, x1 - 3, x2 - 14} map_1_A(x1) = max{2, x1} map_2#!_A(x1,x2) = 11 cons_2!_A(x1,x2) = max{10, x1 - 3, x2 - 17} app#!_A(x1,x2) = max{x1 - 3, x2 + 12} map_1!_A(x1) = max{9, x1 - 2} partial status: pi(map_2#) = [1] pi(cons_2) = [1, 2] pi(app#) = [1, 2] pi(map_1) = [1] The following rules are removed: p1, p2, p3 Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: div_2#(s_1(x),s_1(y)) -> div_2#(minus_2(x,y),s_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(div_0(),y) -> div_1(y) r4: app(div_1(x1),y) -> div_2(x1,y) r5: app(map_0(),y) -> map_1(y) r6: app(map_1(x1),y) -> map_2(x1,y) r7: app(minus_0(),y) -> minus_1(y) r8: app(minus_1(x1),y) -> minus_2(x1,y) r9: app(s_0(),y) -> s_1(y) r10: map_2(f,nil_0()) -> nil_0() r11: map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) r12: minus_2(x,|0|_0()) -> x r13: minus_2(s_1(x),s_1(y)) -> minus_2(x,y) r14: div_2(|0|_0(),s_1(y)) -> |0|_0() r15: div_2(s_1(x),s_1(y)) -> s_1(div_2(minus_2(x,y),s_1(y))) The set of usable rules consists of r12, r13 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: div_2#_A(x1,x2) = x1 + 1 s_1_A(x1) = x1 + 12 minus_2_A(x1,x2) = x1 + 10 |0|_0_A() = 10 base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: div_2#_A(x1,x2) = max{0, x2 - 18} s_1_A(x1) = x1 + 17 minus_2_A(x1,x2) = max{2, x1} |0|_0_A = 3 div_2#!_A(x1,x2) = max{6, x1 - 3} s_1!_A(x1) = max{0, x1 - 29} minus_2!_A(x1,x2) = max{5, x1 - 11, x2 - 18} |0|_0!_A = 0 partial status: pi(div_2#) = [] pi(s_1) = [1] pi(minus_2) = [] pi(|0|_0) = [] 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: 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(div_0(),y) -> div_1(y) r4: app(div_1(x1),y) -> div_2(x1,y) r5: app(map_0(),y) -> map_1(y) r6: app(map_1(x1),y) -> map_2(x1,y) r7: app(minus_0(),y) -> minus_1(y) r8: app(minus_1(x1),y) -> minus_2(x1,y) r9: app(s_0(),y) -> s_1(y) r10: map_2(f,nil_0()) -> nil_0() r11: map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) r12: minus_2(x,|0|_0()) -> x r13: minus_2(s_1(x),s_1(y)) -> minus_2(x,y) r14: div_2(|0|_0(),s_1(y)) -> |0|_0() r15: div_2(s_1(x),s_1(y)) -> s_1(div_2(minus_2(x,y),s_1(y))) The set of usable rules consists of (no rules) 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 base order 2: marked-algebra reduction triple (>=A, >=A!, >A!): max/plus interpretation on natural numbers: minus_2#_A(x1,x2) = 0 s_1_A(x1) = max{4, x1 - 4} minus_2#!_A(x1,x2) = max{4, x1 - 5, x2 - 21} s_1!_A(x1) = max{3, x1 - 21} partial status: pi(minus_2#) = [1] pi(s_1) = [1] The following rules are removed: p1 Then no dependency pair remains.