YES We show the termination of the relative TRS R/S: R: minus(x,|0|()) -> x minus(s(x),s(y)) -> minus(x,y) quot(|0|(),s(y)) -> |0|() quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) app(nil(),y) -> y app(add(n,x),y) -> add(n,app(x,y)) reverse(nil()) -> nil() reverse(add(n,x)) -> app(reverse(x),add(n,nil())) shuffle(nil()) -> nil() shuffle(add(n,x)) -> add(n,shuffle(reverse(x))) concat(leaf(),y) -> y concat(cons(u,v),y) -> cons(u,concat(v,y)) less_leaves(x,leaf()) -> false() less_leaves(leaf(),cons(w,z)) -> true() less_leaves(cons(u,v),cons(w,z)) -> less_leaves(concat(u,v),concat(w,z)) S: rand(x) -> x rand(x) -> rand(s(x)) -- SCC decomposition. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: minus#(s(x),s(y)) -> minus#(x,y) p2: quot#(s(x),s(y)) -> quot#(minus(x,y),s(y)) p3: quot#(s(x),s(y)) -> minus#(x,y) p4: app#(add(n,x),y) -> app#(x,y) p5: reverse#(add(n,x)) -> app#(reverse(x),add(n,nil())) p6: reverse#(add(n,x)) -> reverse#(x) p7: shuffle#(add(n,x)) -> shuffle#(reverse(x)) p8: shuffle#(add(n,x)) -> reverse#(x) p9: concat#(cons(u,v),y) -> concat#(v,y) p10: less_leaves#(cons(u,v),cons(w,z)) -> less_leaves#(concat(u,v),concat(w,z)) p11: less_leaves#(cons(u,v),cons(w,z)) -> concat#(u,v) p12: less_leaves#(cons(u,v),cons(w,z)) -> concat#(w,z) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: quot(|0|(),s(y)) -> |0|() r4: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r5: app(nil(),y) -> y r6: app(add(n,x),y) -> add(n,app(x,y)) r7: reverse(nil()) -> nil() r8: reverse(add(n,x)) -> app(reverse(x),add(n,nil())) r9: shuffle(nil()) -> nil() r10: shuffle(add(n,x)) -> add(n,shuffle(reverse(x))) r11: concat(leaf(),y) -> y r12: concat(cons(u,v),y) -> cons(u,concat(v,y)) r13: less_leaves(x,leaf()) -> false() r14: less_leaves(leaf(),cons(w,z)) -> true() r15: less_leaves(cons(u,v),cons(w,z)) -> less_leaves(concat(u,v),concat(w,z)) r16: rand(x) -> x r17: rand(x) -> rand(s(x)) The estimated dependency graph contains the following SCCs: {p2} {p1} {p7} {p6} {p4} {p10} {p9} -- Reduction pair. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: quot#(s(x),s(y)) -> quot#(minus(x,y),s(y)) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: quot(|0|(),s(y)) -> |0|() r4: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r5: app(nil(),y) -> y r6: app(add(n,x),y) -> add(n,app(x,y)) r7: reverse(nil()) -> nil() r8: reverse(add(n,x)) -> app(reverse(x),add(n,nil())) r9: shuffle(nil()) -> nil() r10: shuffle(add(n,x)) -> add(n,shuffle(reverse(x))) r11: concat(leaf(),y) -> y r12: concat(cons(u,v),y) -> cons(u,concat(v,y)) r13: less_leaves(x,leaf()) -> false() r14: less_leaves(leaf(),cons(w,z)) -> true() r15: less_leaves(cons(u,v),cons(w,z)) -> less_leaves(concat(u,v),concat(w,z)) r16: rand(x) -> x r17: rand(x) -> rand(s(x)) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, r13, r14, r15, r16, r17 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: quot#_A(x1,x2) = x1 s_A(x1) = x1 minus_A(x1,x2) = x1 |0|_A() = (0,0) quot_A(x1,x2) = x1 + (1,1) app_A(x1,x2) = x2 + (3,2) nil_A() = (0,5) add_A(x1,x2) = (3,1) reverse_A(x1) = ((1,0),(1,1)) x1 + (4,0) shuffle_A(x1) = x1 + (2,0) concat_A(x1,x2) = ((1,0),(1,1)) x1 + ((1,0),(1,1)) x2 + (2,8) leaf_A() = (1,1) cons_A(x1,x2) = ((1,0),(1,1)) x1 + x2 + (3,1) less_leaves_A(x1,x2) = ((1,0),(1,1)) x1 + ((1,0),(1,1)) x2 + (2,1) false_A() = (2,2) true_A() = (2,8) rand_A(x1) = ((1,0),(1,0)) x1 + (1,1) precedence: leaf = less_leaves > concat = cons > reverse > app = nil = add = shuffle = false = true = rand > quot > s > quot# = minus = |0| partial status: pi(quot#) = [1] pi(s) = [1] pi(minus) = [1] pi(|0|) = [] pi(quot) = [1] pi(app) = [2] pi(nil) = [] pi(add) = [] pi(reverse) = [1] pi(shuffle) = [] pi(concat) = [1] pi(leaf) = [] pi(cons) = [1] pi(less_leaves) = [] pi(false) = [] pi(true) = [] pi(rand) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: minus#(s(x),s(y)) -> minus#(x,y) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: quot(|0|(),s(y)) -> |0|() r4: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r5: app(nil(),y) -> y r6: app(add(n,x),y) -> add(n,app(x,y)) r7: reverse(nil()) -> nil() r8: reverse(add(n,x)) -> app(reverse(x),add(n,nil())) r9: shuffle(nil()) -> nil() r10: shuffle(add(n,x)) -> add(n,shuffle(reverse(x))) r11: concat(leaf(),y) -> y r12: concat(cons(u,v),y) -> cons(u,concat(v,y)) r13: less_leaves(x,leaf()) -> false() r14: less_leaves(leaf(),cons(w,z)) -> true() r15: less_leaves(cons(u,v),cons(w,z)) -> less_leaves(concat(u,v),concat(w,z)) r16: rand(x) -> x r17: rand(x) -> rand(s(x)) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, r13, r14, r15, r16, r17 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: minus#_A(x1,x2) = x1 + x2 + (1,2) s_A(x1) = x1 + (0,1) minus_A(x1,x2) = x1 |0|_A() = (1,2) quot_A(x1,x2) = x1 + ((0,0),(1,0)) x2 + (1,2) app_A(x1,x2) = x2 + (1,1) nil_A() = (3,3) add_A(x1,x2) = (0,0) reverse_A(x1) = x1 + (2,2) shuffle_A(x1) = x1 + (1,1) concat_A(x1,x2) = ((1,0),(1,1)) x1 + ((1,0),(1,1)) x2 + (1,6) leaf_A() = (2,2) cons_A(x1,x2) = ((1,0),(1,1)) x1 + x2 + (2,1) less_leaves_A(x1,x2) = ((1,0),(1,1)) x1 + x2 + (1,1) false_A() = (1,1) true_A() = (0,0) rand_A(x1) = ((1,0),(1,0)) x1 + (1,2) precedence: minus = reverse = shuffle = concat = rand > nil = leaf = cons > minus# = app > add > s = |0| = quot = less_leaves = false = true partial status: pi(minus#) = [1] pi(s) = [] pi(minus) = [] pi(|0|) = [] pi(quot) = [] pi(app) = [2] pi(nil) = [] pi(add) = [] pi(reverse) = [] pi(shuffle) = [] pi(concat) = [] pi(leaf) = [] pi(cons) = [1, 2] pi(less_leaves) = [1, 2] pi(false) = [] pi(true) = [] pi(rand) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: shuffle#(add(n,x)) -> shuffle#(reverse(x)) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: quot(|0|(),s(y)) -> |0|() r4: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r5: app(nil(),y) -> y r6: app(add(n,x),y) -> add(n,app(x,y)) r7: reverse(nil()) -> nil() r8: reverse(add(n,x)) -> app(reverse(x),add(n,nil())) r9: shuffle(nil()) -> nil() r10: shuffle(add(n,x)) -> add(n,shuffle(reverse(x))) r11: concat(leaf(),y) -> y r12: concat(cons(u,v),y) -> cons(u,concat(v,y)) r13: less_leaves(x,leaf()) -> false() r14: less_leaves(leaf(),cons(w,z)) -> true() r15: less_leaves(cons(u,v),cons(w,z)) -> less_leaves(concat(u,v),concat(w,z)) r16: rand(x) -> x r17: rand(x) -> rand(s(x)) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, r13, r14, r15, r16, r17 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: shuffle#_A(x1) = x1 add_A(x1,x2) = x2 + (0,1) reverse_A(x1) = x1 minus_A(x1,x2) = x1 |0|_A() = (1,2) s_A(x1) = x1 + (0,1) quot_A(x1,x2) = x1 app_A(x1,x2) = x1 + ((1,0),(1,1)) x2 nil_A() = (0,0) shuffle_A(x1) = x1 + (1,2) concat_A(x1,x2) = ((1,0),(1,1)) x1 + ((1,0),(1,1)) x2 + (1,4) leaf_A() = (2,2) cons_A(x1,x2) = ((1,0),(1,1)) x1 + x2 + (2,1) less_leaves_A(x1,x2) = x1 + x2 + (1,1) false_A() = (1,1) true_A() = (1,3) rand_A(x1) = ((1,0),(1,0)) x1 + (1,2) precedence: reverse = s = leaf > less_leaves > concat > nil > quot > minus = app = shuffle > cons > shuffle# = add = |0| = false = true = rand partial status: pi(shuffle#) = [] pi(add) = [] pi(reverse) = [] pi(minus) = [1] pi(|0|) = [] pi(s) = [] pi(quot) = [1] pi(app) = [2] pi(nil) = [] pi(shuffle) = [] pi(concat) = [2] pi(leaf) = [] pi(cons) = [2] pi(less_leaves) = [1] pi(false) = [] pi(true) = [] pi(rand) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: reverse#(add(n,x)) -> reverse#(x) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: quot(|0|(),s(y)) -> |0|() r4: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r5: app(nil(),y) -> y r6: app(add(n,x),y) -> add(n,app(x,y)) r7: reverse(nil()) -> nil() r8: reverse(add(n,x)) -> app(reverse(x),add(n,nil())) r9: shuffle(nil()) -> nil() r10: shuffle(add(n,x)) -> add(n,shuffle(reverse(x))) r11: concat(leaf(),y) -> y r12: concat(cons(u,v),y) -> cons(u,concat(v,y)) r13: less_leaves(x,leaf()) -> false() r14: less_leaves(leaf(),cons(w,z)) -> true() r15: less_leaves(cons(u,v),cons(w,z)) -> less_leaves(concat(u,v),concat(w,z)) r16: rand(x) -> x r17: rand(x) -> rand(s(x)) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, r13, r14, r15, r16, r17 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: reverse#_A(x1) = ((1,0),(1,0)) x1 + (1,2) add_A(x1,x2) = ((1,0),(0,0)) x1 + x2 + (6,1) minus_A(x1,x2) = x1 |0|_A() = (0,1) s_A(x1) = x1 + (0,2) quot_A(x1,x2) = x1 + (0,1) app_A(x1,x2) = x1 + x2 + (0,2) nil_A() = (0,3) reverse_A(x1) = ((1,0),(1,1)) x1 shuffle_A(x1) = ((1,0),(1,0)) x1 + (7,2) concat_A(x1,x2) = ((1,0),(1,1)) x1 + ((1,0),(1,1)) x2 + (1,5) leaf_A() = (2,2) cons_A(x1,x2) = ((1,0),(1,1)) x1 + x2 + (4,4) less_leaves_A(x1,x2) = x1 + x2 + (1,1) false_A() = (1,1) true_A() = (1,3) rand_A(x1) = ((1,0),(0,0)) x1 + (1,3) precedence: minus = nil = reverse = leaf = true = rand > reverse# = add = app = shuffle > concat = cons = less_leaves > |0| = s = quot = false partial status: pi(reverse#) = [] pi(add) = [] pi(minus) = [] pi(|0|) = [] pi(s) = [] pi(quot) = [] pi(app) = [2] pi(nil) = [] pi(reverse) = [] pi(shuffle) = [] pi(concat) = [] pi(leaf) = [] pi(cons) = [] pi(less_leaves) = [] pi(false) = [] pi(true) = [] pi(rand) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: app#(add(n,x),y) -> app#(x,y) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: quot(|0|(),s(y)) -> |0|() r4: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r5: app(nil(),y) -> y r6: app(add(n,x),y) -> add(n,app(x,y)) r7: reverse(nil()) -> nil() r8: reverse(add(n,x)) -> app(reverse(x),add(n,nil())) r9: shuffle(nil()) -> nil() r10: shuffle(add(n,x)) -> add(n,shuffle(reverse(x))) r11: concat(leaf(),y) -> y r12: concat(cons(u,v),y) -> cons(u,concat(v,y)) r13: less_leaves(x,leaf()) -> false() r14: less_leaves(leaf(),cons(w,z)) -> true() r15: less_leaves(cons(u,v),cons(w,z)) -> less_leaves(concat(u,v),concat(w,z)) r16: rand(x) -> x r17: rand(x) -> rand(s(x)) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, r13, r14, r15, r16, r17 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: app#_A(x1,x2) = ((1,0),(1,0)) x1 + (5,2) add_A(x1,x2) = ((1,0),(0,0)) x2 + (4,1) minus_A(x1,x2) = x1 + (0,3) |0|_A() = (1,1) s_A(x1) = x1 quot_A(x1,x2) = (2,2) app_A(x1,x2) = x1 + x2 + (0,2) nil_A() = (0,2) reverse_A(x1) = ((1,0),(1,0)) x1 + (0,3) shuffle_A(x1) = x1 + (5,1) concat_A(x1,x2) = ((1,0),(1,1)) x1 + ((1,0),(1,1)) x2 + (1,4) leaf_A() = (1,1) cons_A(x1,x2) = ((1,0),(1,1)) x1 + x2 + (2,1) less_leaves_A(x1,x2) = x1 + x2 + (2,1) false_A() = (2,3) true_A() = (0,0) rand_A(x1) = x1 + (1,1) precedence: s = quot = reverse > minus = shuffle = concat = leaf = false = true = rand > add = |0| = app = nil > cons = less_leaves > app# partial status: pi(app#) = [] pi(add) = [] pi(minus) = [1] pi(|0|) = [] pi(s) = [] pi(quot) = [] pi(app) = [2] pi(nil) = [] pi(reverse) = [] pi(shuffle) = [] pi(concat) = [] pi(leaf) = [] pi(cons) = [] pi(less_leaves) = [1, 2] pi(false) = [] pi(true) = [] pi(rand) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: less_leaves#(cons(u,v),cons(w,z)) -> less_leaves#(concat(u,v),concat(w,z)) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: quot(|0|(),s(y)) -> |0|() r4: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r5: app(nil(),y) -> y r6: app(add(n,x),y) -> add(n,app(x,y)) r7: reverse(nil()) -> nil() r8: reverse(add(n,x)) -> app(reverse(x),add(n,nil())) r9: shuffle(nil()) -> nil() r10: shuffle(add(n,x)) -> add(n,shuffle(reverse(x))) r11: concat(leaf(),y) -> y r12: concat(cons(u,v),y) -> cons(u,concat(v,y)) r13: less_leaves(x,leaf()) -> false() r14: less_leaves(leaf(),cons(w,z)) -> true() r15: less_leaves(cons(u,v),cons(w,z)) -> less_leaves(concat(u,v),concat(w,z)) r16: rand(x) -> x r17: rand(x) -> rand(s(x)) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, r13, r14, r15, r16, r17 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: less_leaves#_A(x1,x2) = x1 + (1,2) cons_A(x1,x2) = ((1,0),(1,1)) x1 + x2 + (4,2) concat_A(x1,x2) = ((1,0),(1,1)) x1 + x2 + (1,1) minus_A(x1,x2) = ((1,0),(0,0)) x1 + ((1,0),(0,0)) x2 + (3,3) |0|_A() = (1,1) s_A(x1) = x1 quot_A(x1,x2) = ((0,0),(1,0)) x2 + (2,2) app_A(x1,x2) = x2 + (0,1) nil_A() = (0,1) add_A(x1,x2) = (0,0) reverse_A(x1) = (0,2) shuffle_A(x1) = x1 + (0,3) leaf_A() = (6,2) less_leaves_A(x1,x2) = x2 + (2,2) false_A() = (1,1) true_A() = (5,5) rand_A(x1) = ((1,0),(1,1)) x1 + (1,1) precedence: concat = minus > less_leaves# = cons = |0| = s = quot > app = nil = add = reverse = shuffle = leaf = less_leaves = rand > false = true partial status: pi(less_leaves#) = [1] pi(cons) = [] pi(concat) = [] pi(minus) = [] pi(|0|) = [] pi(s) = [] pi(quot) = [] pi(app) = [] pi(nil) = [] pi(add) = [] pi(reverse) = [] pi(shuffle) = [] pi(leaf) = [] pi(less_leaves) = [] pi(false) = [] pi(true) = [] pi(rand) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains. -- Reduction pair. Consider the non-minimal dependency pair problem (P, R), where P consists of p1: concat#(cons(u,v),y) -> concat#(v,y) and R consists of: r1: minus(x,|0|()) -> x r2: minus(s(x),s(y)) -> minus(x,y) r3: quot(|0|(),s(y)) -> |0|() r4: quot(s(x),s(y)) -> s(quot(minus(x,y),s(y))) r5: app(nil(),y) -> y r6: app(add(n,x),y) -> add(n,app(x,y)) r7: reverse(nil()) -> nil() r8: reverse(add(n,x)) -> app(reverse(x),add(n,nil())) r9: shuffle(nil()) -> nil() r10: shuffle(add(n,x)) -> add(n,shuffle(reverse(x))) r11: concat(leaf(),y) -> y r12: concat(cons(u,v),y) -> cons(u,concat(v,y)) r13: less_leaves(x,leaf()) -> false() r14: less_leaves(leaf(),cons(w,z)) -> true() r15: less_leaves(cons(u,v),cons(w,z)) -> less_leaves(concat(u,v),concat(w,z)) r16: rand(x) -> x r17: rand(x) -> rand(s(x)) The set of usable rules consists of r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11, r12, r13, r14, r15, r16, r17 Take the reduction pair: weighted path order base order: matrix interpretations: carrier: N^2 order: lexicographic order interpretations: concat#_A(x1,x2) = ((0,0),(1,0)) x1 + x2 + (3,1) cons_A(x1,x2) = ((1,0),(1,1)) x1 + x2 + (2,2) minus_A(x1,x2) = ((1,0),(1,0)) x1 + (3,4) |0|_A() = (1,2) s_A(x1) = ((1,0),(0,0)) x1 + (0,1) quot_A(x1,x2) = (2,3) app_A(x1,x2) = x2 + (2,2) nil_A() = (2,4) add_A(x1,x2) = ((0,0),(1,0)) x1 + (1,3) reverse_A(x1) = (4,1) shuffle_A(x1) = (5,2) concat_A(x1,x2) = ((1,0),(1,1)) x1 + ((1,0),(1,1)) x2 + (1,1) leaf_A() = (2,2) less_leaves_A(x1,x2) = x1 + x2 + (1,1) false_A() = (1,1) true_A() = (0,0) rand_A(x1) = ((1,0),(0,0)) x1 + (1,2) precedence: concat# = cons = minus = app = nil = add = reverse = shuffle = concat = leaf = false = true = rand > less_leaves > |0| = s = quot partial status: pi(concat#) = [] pi(cons) = [] pi(minus) = [] pi(|0|) = [] pi(s) = [] pi(quot) = [] pi(app) = [] pi(nil) = [] pi(add) = [] pi(reverse) = [] pi(shuffle) = [] pi(concat) = [] pi(leaf) = [] pi(less_leaves) = [2] pi(false) = [] pi(true) = [] pi(rand) = [] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.