YES We show the termination of the TRS R: +(x,|0|()) -> x +(|0|(),x) -> x +(s(x),s(y)) -> s(s(+(x,y))) +(+(x,y),z) -> +(x,+(y,z)) *(x,|0|()) -> |0|() *(|0|(),x) -> |0|() *(s(x),s(y)) -> s(+(*(x,y),+(x,y))) *(*(x,y),z) -> *(x,*(y,z)) app(nil(),l) -> l app(cons(x,l1),l2) -> cons(x,app(l1,l2)) sum(nil()) -> |0|() sum(cons(x,l)) -> +(x,sum(l)) sum(app(l1,l2)) -> +(sum(l1),sum(l2)) prod(nil()) -> s(|0|()) prod(cons(x,l)) -> *(x,prod(l)) prod(app(l1,l2)) -> *(prod(l1),prod(l2)) -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: +#(s(x),s(y)) -> +#(x,y) p2: +#(+(x,y),z) -> +#(x,+(y,z)) p3: +#(+(x,y),z) -> +#(y,z) p4: *#(s(x),s(y)) -> +#(*(x,y),+(x,y)) p5: *#(s(x),s(y)) -> *#(x,y) p6: *#(s(x),s(y)) -> +#(x,y) p7: *#(*(x,y),z) -> *#(x,*(y,z)) p8: *#(*(x,y),z) -> *#(y,z) p9: app#(cons(x,l1),l2) -> app#(l1,l2) p10: sum#(cons(x,l)) -> +#(x,sum(l)) p11: sum#(cons(x,l)) -> sum#(l) p12: sum#(app(l1,l2)) -> +#(sum(l1),sum(l2)) p13: sum#(app(l1,l2)) -> sum#(l1) p14: sum#(app(l1,l2)) -> sum#(l2) p15: prod#(cons(x,l)) -> *#(x,prod(l)) p16: prod#(cons(x,l)) -> prod#(l) p17: prod#(app(l1,l2)) -> *#(prod(l1),prod(l2)) p18: prod#(app(l1,l2)) -> prod#(l1) p19: prod#(app(l1,l2)) -> prod#(l2) and R consists of: r1: +(x,|0|()) -> x r2: +(|0|(),x) -> x r3: +(s(x),s(y)) -> s(s(+(x,y))) r4: +(+(x,y),z) -> +(x,+(y,z)) r5: *(x,|0|()) -> |0|() r6: *(|0|(),x) -> |0|() r7: *(s(x),s(y)) -> s(+(*(x,y),+(x,y))) r8: *(*(x,y),z) -> *(x,*(y,z)) r9: app(nil(),l) -> l r10: app(cons(x,l1),l2) -> cons(x,app(l1,l2)) r11: sum(nil()) -> |0|() r12: sum(cons(x,l)) -> +(x,sum(l)) r13: sum(app(l1,l2)) -> +(sum(l1),sum(l2)) r14: prod(nil()) -> s(|0|()) r15: prod(cons(x,l)) -> *(x,prod(l)) r16: prod(app(l1,l2)) -> *(prod(l1),prod(l2)) The estimated dependency graph contains the following SCCs: {p11, p13, p14} {p16, p18, p19} {p5, p7, p8} {p1, p2, p3} {p9} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: sum#(app(l1,l2)) -> sum#(l2) p2: sum#(app(l1,l2)) -> sum#(l1) p3: sum#(cons(x,l)) -> sum#(l) and R consists of: r1: +(x,|0|()) -> x r2: +(|0|(),x) -> x r3: +(s(x),s(y)) -> s(s(+(x,y))) r4: +(+(x,y),z) -> +(x,+(y,z)) r5: *(x,|0|()) -> |0|() r6: *(|0|(),x) -> |0|() r7: *(s(x),s(y)) -> s(+(*(x,y),+(x,y))) r8: *(*(x,y),z) -> *(x,*(y,z)) r9: app(nil(),l) -> l r10: app(cons(x,l1),l2) -> cons(x,app(l1,l2)) r11: sum(nil()) -> |0|() r12: sum(cons(x,l)) -> +(x,sum(l)) r13: sum(app(l1,l2)) -> +(sum(l1),sum(l2)) r14: prod(nil()) -> s(|0|()) r15: prod(cons(x,l)) -> *(x,prod(l)) r16: prod(app(l1,l2)) -> *(prod(l1),prod(l2)) The set of usable rules consists of (no rules) Take the reduction pair: lexicographic combination of reduction pairs: 1. lexicographic path order with precedence: precedence: sum# > cons > app argument filter: pi(sum#) = [1] pi(app) = [1, 2] pi(cons) = [2] 2. lexicographic path order with precedence: precedence: sum# > cons > app argument filter: pi(sum#) = [1] pi(app) = [1] pi(cons) = [2] The next rules are strictly ordered: p1, p2, p3 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: prod#(app(l1,l2)) -> prod#(l2) p2: prod#(app(l1,l2)) -> prod#(l1) p3: prod#(cons(x,l)) -> prod#(l) and R consists of: r1: +(x,|0|()) -> x r2: +(|0|(),x) -> x r3: +(s(x),s(y)) -> s(s(+(x,y))) r4: +(+(x,y),z) -> +(x,+(y,z)) r5: *(x,|0|()) -> |0|() r6: *(|0|(),x) -> |0|() r7: *(s(x),s(y)) -> s(+(*(x,y),+(x,y))) r8: *(*(x,y),z) -> *(x,*(y,z)) r9: app(nil(),l) -> l r10: app(cons(x,l1),l2) -> cons(x,app(l1,l2)) r11: sum(nil()) -> |0|() r12: sum(cons(x,l)) -> +(x,sum(l)) r13: sum(app(l1,l2)) -> +(sum(l1),sum(l2)) r14: prod(nil()) -> s(|0|()) r15: prod(cons(x,l)) -> *(x,prod(l)) r16: prod(app(l1,l2)) -> *(prod(l1),prod(l2)) The set of usable rules consists of (no rules) Take the reduction pair: lexicographic combination of reduction pairs: 1. lexicographic path order with precedence: precedence: prod# > cons > app argument filter: pi(prod#) = [1] pi(app) = [1, 2] pi(cons) = [2] 2. lexicographic path order with precedence: precedence: prod# > cons > app argument filter: pi(prod#) = [1] pi(app) = [1] pi(cons) = [2] The next rules are strictly ordered: p1, p2, p3 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: *#(*(x,y),z) -> *#(y,z) p2: *#(*(x,y),z) -> *#(x,*(y,z)) p3: *#(s(x),s(y)) -> *#(x,y) and R consists of: r1: +(x,|0|()) -> x r2: +(|0|(),x) -> x r3: +(s(x),s(y)) -> s(s(+(x,y))) r4: +(+(x,y),z) -> +(x,+(y,z)) r5: *(x,|0|()) -> |0|() r6: *(|0|(),x) -> |0|() r7: *(s(x),s(y)) -> s(+(*(x,y),+(x,y))) r8: *(*(x,y),z) -> *(x,*(y,z)) r9: app(nil(),l) -> l r10: app(cons(x,l1),l2) -> cons(x,app(l1,l2)) r11: sum(nil()) -> |0|() r12: sum(cons(x,l)) -> +(x,sum(l)) r13: sum(app(l1,l2)) -> +(sum(l1),sum(l2)) r14: prod(nil()) -> s(|0|()) r15: prod(cons(x,l)) -> *(x,prod(l)) r16: prod(app(l1,l2)) -> *(prod(l1),prod(l2)) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8 Take the reduction pair: lexicographic combination of reduction pairs: 1. lexicographic path order with precedence: precedence: |0| > * > + > *# > s argument filter: pi(*#) = [1] pi(*) = [1, 2] pi(s) = [1] pi(+) = [1, 2] pi(|0|) = [] 2. lexicographic path order with precedence: precedence: |0| > + > *# > s > * argument filter: pi(*#) = [] pi(*) = 2 pi(s) = [1] pi(+) = 2 pi(|0|) = [] The next rules are strictly ordered: p1, p2, p3 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: +#(s(x),s(y)) -> +#(x,y) p2: +#(+(x,y),z) -> +#(y,z) p3: +#(+(x,y),z) -> +#(x,+(y,z)) and R consists of: r1: +(x,|0|()) -> x r2: +(|0|(),x) -> x r3: +(s(x),s(y)) -> s(s(+(x,y))) r4: +(+(x,y),z) -> +(x,+(y,z)) r5: *(x,|0|()) -> |0|() r6: *(|0|(),x) -> |0|() r7: *(s(x),s(y)) -> s(+(*(x,y),+(x,y))) r8: *(*(x,y),z) -> *(x,*(y,z)) r9: app(nil(),l) -> l r10: app(cons(x,l1),l2) -> cons(x,app(l1,l2)) r11: sum(nil()) -> |0|() r12: sum(cons(x,l)) -> +(x,sum(l)) r13: sum(app(l1,l2)) -> +(sum(l1),sum(l2)) r14: prod(nil()) -> s(|0|()) r15: prod(cons(x,l)) -> *(x,prod(l)) r16: prod(app(l1,l2)) -> *(prod(l1),prod(l2)) The set of usable rules consists of r1, r2, r3, r4 Take the reduction pair: lexicographic combination of reduction pairs: 1. lexicographic path order with precedence: precedence: |0| > +# > + > s argument filter: pi(+#) = [1, 2] pi(s) = [1] pi(+) = [1, 2] pi(|0|) = [] 2. lexicographic path order with precedence: precedence: |0| > +# > + > s argument filter: pi(+#) = [1, 2] pi(s) = [1] pi(+) = 2 pi(|0|) = [] The next rules are strictly ordered: p1, p2, p3 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: app#(cons(x,l1),l2) -> app#(l1,l2) and R consists of: r1: +(x,|0|()) -> x r2: +(|0|(),x) -> x r3: +(s(x),s(y)) -> s(s(+(x,y))) r4: +(+(x,y),z) -> +(x,+(y,z)) r5: *(x,|0|()) -> |0|() r6: *(|0|(),x) -> |0|() r7: *(s(x),s(y)) -> s(+(*(x,y),+(x,y))) r8: *(*(x,y),z) -> *(x,*(y,z)) r9: app(nil(),l) -> l r10: app(cons(x,l1),l2) -> cons(x,app(l1,l2)) r11: sum(nil()) -> |0|() r12: sum(cons(x,l)) -> +(x,sum(l)) r13: sum(app(l1,l2)) -> +(sum(l1),sum(l2)) r14: prod(nil()) -> s(|0|()) r15: prod(cons(x,l)) -> *(x,prod(l)) r16: prod(app(l1,l2)) -> *(prod(l1),prod(l2)) The set of usable rules consists of (no rules) Take the reduction pair: lexicographic combination of reduction pairs: 1. lexicographic path order with precedence: precedence: cons > app# argument filter: pi(app#) = [1] pi(cons) = [1, 2] 2. lexicographic path order with precedence: precedence: cons > app# argument filter: pi(app#) = [1] pi(cons) = [1, 2] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.