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(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)) inc() -> app(map(),app(plus(),app(s(),|0|()))) double() -> app(map(),app(times(),app(s(),app(s(),|0|())))) 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(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) map_2(f,nil_0()) -> nil_0() map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) inc_0() -> map_1(plus_1(s_1(|0|_0()))) double_0() -> map_1(times_1(s_1(s_1(|0|_0())))) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: app#(map_1(x1),y) -> map_2#(x1,y) p2: app#(plus_1(x1),y) -> plus_2#(x1,y) p3: app#(times_1(x1),y) -> times_2#(x1,y) p4: plus_2#(s_1(x),y) -> plus_2#(x,y) p5: times_2#(s_1(x),y) -> plus_2#(times_2(x,y),y) p6: times_2#(s_1(x),y) -> times_2#(x,y) p7: map_2#(f,cons_2(x,xs)) -> app#(f,x) p8: 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(map_0(),y) -> map_1(y) r4: app(map_1(x1),y) -> map_2(x1,y) r5: app(plus_0(),y) -> plus_1(y) r6: app(plus_1(x1),y) -> plus_2(x1,y) r7: app(s_0(),y) -> s_1(y) r8: app(times_0(),y) -> times_1(y) r9: app(times_1(x1),y) -> times_2(x1,y) r10: plus_2(|0|_0(),y) -> y r11: plus_2(s_1(x),y) -> s_1(plus_2(x,y)) r12: times_2(|0|_0(),y) -> |0|_0() r13: times_2(s_1(x),y) -> plus_2(times_2(x,y),y) r14: map_2(f,nil_0()) -> nil_0() r15: map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) r16: inc_0() -> map_1(plus_1(s_1(|0|_0()))) r17: double_0() -> map_1(times_1(s_1(s_1(|0|_0())))) The estimated dependency graph contains the following SCCs: {p1, p7, p8} {p6} {p4} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: app#(map_1(x1),y) -> map_2#(x1,y) p2: map_2#(f,cons_2(x,xs)) -> map_2#(f,xs) p3: map_2#(f,cons_2(x,xs)) -> app#(f,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(map_0(),y) -> map_1(y) r4: app(map_1(x1),y) -> map_2(x1,y) r5: app(plus_0(),y) -> plus_1(y) r6: app(plus_1(x1),y) -> plus_2(x1,y) r7: app(s_0(),y) -> s_1(y) r8: app(times_0(),y) -> times_1(y) r9: app(times_1(x1),y) -> times_2(x1,y) r10: plus_2(|0|_0(),y) -> y r11: plus_2(s_1(x),y) -> s_1(plus_2(x,y)) r12: times_2(|0|_0(),y) -> |0|_0() r13: times_2(s_1(x),y) -> plus_2(times_2(x,y),y) r14: map_2(f,nil_0()) -> nil_0() r15: map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) r16: inc_0() -> map_1(plus_1(s_1(|0|_0()))) r17: double_0() -> map_1(times_1(s_1(s_1(|0|_0())))) The set of usable rules consists of r16, r17 Take the reduction pair: generalized weighted path order (>=MG, >MG) base order 1: max/plus interpretation on natural numbers: app#_A(x1,x2) = x2 + 5 map_1_A(x1) = max{2, x1 - 11} map_2#_A(x1,x2) = max{3, x2 - 2} cons_2_A(x1,x2) = max{x1 + 8, x2 + 1} inc_0_A = 11 plus_1_A(x1) = max{10, x1 - 14} s_1_A(x1) = max{2, x1 - 12} |0|_0_A = 0 double_0_A = 11 times_1_A(x1) = max{10, x1 - 5} base order 2: precedence: inc_0 = double_0 > |0|_0 = times_1 > map_1 = plus_1 = s_1 > cons_2 > map_2# > app# partial status: pi(app#) = [] pi(map_1) = [] pi(map_2#) = [] pi(cons_2) = [1] pi(inc_0) = [] pi(plus_1) = [] pi(s_1) = [] pi(|0|_0) = [] pi(double_0) = [] pi(times_1) = [] The following rules are removed: p2 -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: app#(map_1(x1),y) -> map_2#(x1,y) p2: map_2#(f,cons_2(x,xs)) -> app#(f,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(map_0(),y) -> map_1(y) r4: app(map_1(x1),y) -> map_2(x1,y) r5: app(plus_0(),y) -> plus_1(y) r6: app(plus_1(x1),y) -> plus_2(x1,y) r7: app(s_0(),y) -> s_1(y) r8: app(times_0(),y) -> times_1(y) r9: app(times_1(x1),y) -> times_2(x1,y) r10: plus_2(|0|_0(),y) -> y r11: plus_2(s_1(x),y) -> s_1(plus_2(x,y)) r12: times_2(|0|_0(),y) -> |0|_0() r13: times_2(s_1(x),y) -> plus_2(times_2(x,y),y) r14: map_2(f,nil_0()) -> nil_0() r15: map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) r16: inc_0() -> map_1(plus_1(s_1(|0|_0()))) r17: double_0() -> map_1(times_1(s_1(s_1(|0|_0())))) The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: app#(map_1(x1),y) -> map_2#(x1,y) p2: map_2#(f,cons_2(x,xs)) -> app#(f,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(map_0(),y) -> map_1(y) r4: app(map_1(x1),y) -> map_2(x1,y) r5: app(plus_0(),y) -> plus_1(y) r6: app(plus_1(x1),y) -> plus_2(x1,y) r7: app(s_0(),y) -> s_1(y) r8: app(times_0(),y) -> times_1(y) r9: app(times_1(x1),y) -> times_2(x1,y) r10: plus_2(|0|_0(),y) -> y r11: plus_2(s_1(x),y) -> s_1(plus_2(x,y)) r12: times_2(|0|_0(),y) -> |0|_0() r13: times_2(s_1(x),y) -> plus_2(times_2(x,y),y) r14: map_2(f,nil_0()) -> nil_0() r15: map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) r16: inc_0() -> map_1(plus_1(s_1(|0|_0()))) r17: double_0() -> map_1(times_1(s_1(s_1(|0|_0())))) The set of usable rules consists of r1, r3, r5, r7, r8, r16, r17 Take the reduction pair: generalized weighted path order (>=MG, >MG) base order 1: max/plus interpretation on natural numbers: app#_A(x1,x2) = max{11, x2 + 10} map_1_A(x1) = max{2, x1 - 11} map_2#_A(x1,x2) = max{11, x2 + 1} cons_2_A(x1,x2) = max{x1 + 9, x2 - 12} app_A(x1,x2) = max{7, x1 - 5, x2 - 10} cons_0_A = 3 cons_1_A(x1) = max{4, x1 - 11} map_0_A = 1 plus_0_A = 3 plus_1_A(x1) = max{4, x1 - 11} s_0_A = 1 s_1_A(x1) = max{2, x1 - 18} times_0_A = 3 times_1_A(x1) = max{4, x1 - 11} inc_0_A = 3 |0|_0_A = 0 double_0_A = 5 base order 2: precedence: app# = map_2# = app > cons_2 = double_0 > cons_1 = times_1 > cons_0 = plus_1 = times_0 > plus_0 = inc_0 > map_1 = s_1 = |0|_0 > map_0 = s_0 partial status: pi(app#) = [2] pi(map_1) = [] pi(map_2#) = [2] pi(cons_2) = [1] pi(app) = [] pi(cons_0) = [] pi(cons_1) = [] pi(map_0) = [] pi(plus_0) = [] pi(plus_1) = [] pi(s_0) = [] pi(s_1) = [] pi(times_0) = [] pi(times_1) = [] pi(inc_0) = [] pi(|0|_0) = [] pi(double_0) = [] The following rules are removed: p2 -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: app#(map_1(x1),y) -> map_2#(x1,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(map_0(),y) -> map_1(y) r4: app(map_1(x1),y) -> map_2(x1,y) r5: app(plus_0(),y) -> plus_1(y) r6: app(plus_1(x1),y) -> plus_2(x1,y) r7: app(s_0(),y) -> s_1(y) r8: app(times_0(),y) -> times_1(y) r9: app(times_1(x1),y) -> times_2(x1,y) r10: plus_2(|0|_0(),y) -> y r11: plus_2(s_1(x),y) -> s_1(plus_2(x,y)) r12: times_2(|0|_0(),y) -> |0|_0() r13: times_2(s_1(x),y) -> plus_2(times_2(x,y),y) r14: map_2(f,nil_0()) -> nil_0() r15: map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) r16: inc_0() -> map_1(plus_1(s_1(|0|_0()))) r17: double_0() -> map_1(times_1(s_1(s_1(|0|_0())))) The estimated dependency graph contains the following SCCs: (no SCCs) -- 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(map_0(),y) -> map_1(y) r4: app(map_1(x1),y) -> map_2(x1,y) r5: app(plus_0(),y) -> plus_1(y) r6: app(plus_1(x1),y) -> plus_2(x1,y) r7: app(s_0(),y) -> s_1(y) r8: app(times_0(),y) -> times_1(y) r9: app(times_1(x1),y) -> times_2(x1,y) r10: plus_2(|0|_0(),y) -> y r11: plus_2(s_1(x),y) -> s_1(plus_2(x,y)) r12: times_2(|0|_0(),y) -> |0|_0() r13: times_2(s_1(x),y) -> plus_2(times_2(x,y),y) r14: map_2(f,nil_0()) -> nil_0() r15: map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) r16: inc_0() -> map_1(plus_1(s_1(|0|_0()))) r17: double_0() -> map_1(times_1(s_1(s_1(|0|_0())))) The set of usable rules consists of r1, r2, r3, r5, r8, r16, r17 Take the reduction pair: generalized weighted path order (>=MG, >MG) base order 1: max/plus interpretation on natural numbers: times_2#_A(x1,x2) = x1 + 1 s_1_A(x1) = x1 + 3 app_A(x1,x2) = max{6, x1 - 7, x2 - 3} cons_0_A = 5 cons_1_A(x1) = max{6, x1 - 3} cons_2_A(x1,x2) = max{1, x1 - 13, x2 - 6} map_0_A = 1 map_1_A(x1) = max{2, x1 - 4} plus_0_A = 8 plus_1_A(x1) = max{3, x1 - 4} times_0_A = 8 times_1_A(x1) = max{3, x1 - 7} inc_0_A = 4 |0|_0_A = 0 double_0_A = 7 base order 2: precedence: app > cons_0 = inc_0 = double_0 > s_1 = cons_1 = cons_2 = map_1 = plus_1 = times_1 = |0|_0 > times_2# = map_0 = plus_0 = times_0 partial status: pi(times_2#) = [1] pi(s_1) = [1] pi(app) = [] pi(cons_0) = [] pi(cons_1) = [] pi(cons_2) = [] pi(map_0) = [] pi(map_1) = [] pi(plus_0) = [] pi(plus_1) = [] pi(times_0) = [] pi(times_1) = [] pi(inc_0) = [] pi(|0|_0) = [] pi(double_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: 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(map_0(),y) -> map_1(y) r4: app(map_1(x1),y) -> map_2(x1,y) r5: app(plus_0(),y) -> plus_1(y) r6: app(plus_1(x1),y) -> plus_2(x1,y) r7: app(s_0(),y) -> s_1(y) r8: app(times_0(),y) -> times_1(y) r9: app(times_1(x1),y) -> times_2(x1,y) r10: plus_2(|0|_0(),y) -> y r11: plus_2(s_1(x),y) -> s_1(plus_2(x,y)) r12: times_2(|0|_0(),y) -> |0|_0() r13: times_2(s_1(x),y) -> plus_2(times_2(x,y),y) r14: map_2(f,nil_0()) -> nil_0() r15: map_2(f,cons_2(x,xs)) -> cons_2(app(f,x),map_2(f,xs)) r16: inc_0() -> map_1(plus_1(s_1(|0|_0()))) r17: double_0() -> map_1(times_1(s_1(s_1(|0|_0())))) The set of usable rules consists of r1, r2, r3, r5, r8, r16, r17 Take the reduction pair: generalized weighted path order (>=MG, >MG) base order 1: max/plus interpretation on natural numbers: plus_2#_A(x1,x2) = max{4, x1 + 1} s_1_A(x1) = max{10, x1 + 5} app_A(x1,x2) = max{4, x1 - 11, x2 - 11} cons_0_A = 3 cons_1_A(x1) = max{4, x1 - 11} cons_2_A(x1,x2) = max{1, x1 - 23, x2 - 12} map_0_A = 14 map_1_A(x1) = max{2, x1 - 13} plus_0_A = 23 plus_1_A(x1) = max{12, x1 - 11} times_0_A = 10 times_1_A(x1) = max{3, x1 - 16} inc_0_A = 13 |0|_0_A = 0 double_0_A = 16 base order 2: precedence: app = inc_0 = double_0 > map_1 > times_0 > s_1 = cons_2 = map_0 = plus_1 = times_1 = |0|_0 > plus_2# = cons_1 = plus_0 > cons_0 partial status: pi(plus_2#) = [1] pi(s_1) = [1] pi(app) = [] pi(cons_0) = [] pi(cons_1) = [] pi(cons_2) = [] pi(map_0) = [] pi(map_1) = [] pi(plus_0) = [] pi(plus_1) = [] pi(times_0) = [] pi(times_1) = [] pi(inc_0) = [] pi(|0|_0) = [] pi(double_0) = [] The following rules are removed: p1 Then no dependency pair remains.