YES We show the termination of the TRS 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))) le(|0|(),y) -> true() le(s(x),|0|()) -> false() le(s(x),s(y)) -> le(x,y) app(nil(),y) -> y app(add(n,x),y) -> add(n,app(x,y)) low(n,nil()) -> nil() low(n,add(m,x)) -> if_low(le(m,n),n,add(m,x)) if_low(true(),n,add(m,x)) -> add(m,low(n,x)) if_low(false(),n,add(m,x)) -> low(n,x) high(n,nil()) -> nil() high(n,add(m,x)) -> if_high(le(m,n),n,add(m,x)) if_high(true(),n,add(m,x)) -> high(n,x) if_high(false(),n,add(m,x)) -> add(m,high(n,x)) quicksort(nil()) -> nil() quicksort(add(n,x)) -> app(quicksort(low(n,x)),add(n,quicksort(high(n,x)))) -- SCC decomposition. Consider the 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: le#(s(x),s(y)) -> le#(x,y) p5: app#(add(n,x),y) -> app#(x,y) p6: low#(n,add(m,x)) -> if_low#(le(m,n),n,add(m,x)) p7: low#(n,add(m,x)) -> le#(m,n) p8: if_low#(true(),n,add(m,x)) -> low#(n,x) p9: if_low#(false(),n,add(m,x)) -> low#(n,x) p10: high#(n,add(m,x)) -> if_high#(le(m,n),n,add(m,x)) p11: high#(n,add(m,x)) -> le#(m,n) p12: if_high#(true(),n,add(m,x)) -> high#(n,x) p13: if_high#(false(),n,add(m,x)) -> high#(n,x) p14: quicksort#(add(n,x)) -> app#(quicksort(low(n,x)),add(n,quicksort(high(n,x)))) p15: quicksort#(add(n,x)) -> quicksort#(low(n,x)) p16: quicksort#(add(n,x)) -> low#(n,x) p17: quicksort#(add(n,x)) -> quicksort#(high(n,x)) p18: quicksort#(add(n,x)) -> high#(n,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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: low(n,nil()) -> nil() r11: low(n,add(m,x)) -> if_low(le(m,n),n,add(m,x)) r12: if_low(true(),n,add(m,x)) -> add(m,low(n,x)) r13: if_low(false(),n,add(m,x)) -> low(n,x) r14: high(n,nil()) -> nil() r15: high(n,add(m,x)) -> if_high(le(m,n),n,add(m,x)) r16: if_high(true(),n,add(m,x)) -> high(n,x) r17: if_high(false(),n,add(m,x)) -> add(m,high(n,x)) r18: quicksort(nil()) -> nil() r19: quicksort(add(n,x)) -> app(quicksort(low(n,x)),add(n,quicksort(high(n,x)))) The estimated dependency graph contains the following SCCs: {p2} {p1} {p15, p17} {p10, p12, p13} {p6, p8, p9} {p4} {p5} -- Reduction pair. Consider the 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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: low(n,nil()) -> nil() r11: low(n,add(m,x)) -> if_low(le(m,n),n,add(m,x)) r12: if_low(true(),n,add(m,x)) -> add(m,low(n,x)) r13: if_low(false(),n,add(m,x)) -> low(n,x) r14: high(n,nil()) -> nil() r15: high(n,add(m,x)) -> if_high(le(m,n),n,add(m,x)) r16: if_high(true(),n,add(m,x)) -> high(n,x) r17: if_high(false(),n,add(m,x)) -> add(m,high(n,x)) r18: quicksort(nil()) -> nil() r19: quicksort(add(n,x)) -> app(quicksort(low(n,x)),add(n,quicksort(high(n,x)))) The set of usable rules consists of r1, r2 Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: quot#_A(x1,x2) = max{3, x1 + 1} s_A(x1) = max{4, x1 + 2} minus_A(x1,x2) = x1 + 1 |0|_A = 0 precedence: s > quot# = minus = |0| partial status: pi(quot#) = [1] pi(s) = [] pi(minus) = [1] pi(|0|) = [] The next rules are strictly ordered: p1 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: 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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: low(n,nil()) -> nil() r11: low(n,add(m,x)) -> if_low(le(m,n),n,add(m,x)) r12: if_low(true(),n,add(m,x)) -> add(m,low(n,x)) r13: if_low(false(),n,add(m,x)) -> low(n,x) r14: high(n,nil()) -> nil() r15: high(n,add(m,x)) -> if_high(le(m,n),n,add(m,x)) r16: if_high(true(),n,add(m,x)) -> high(n,x) r17: if_high(false(),n,add(m,x)) -> add(m,high(n,x)) r18: quicksort(nil()) -> nil() r19: quicksort(add(n,x)) -> app(quicksort(low(n,x)),add(n,quicksort(high(n,x)))) The set of usable rules consists of (no rules) Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: minus#_A(x1,x2) = max{0, x1 - 2, x2 - 2} s_A(x1) = max{3, x1 + 1} precedence: minus# = s partial status: pi(minus#) = [] pi(s) = [] The next rules are strictly ordered: p1 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: quicksort#(add(n,x)) -> quicksort#(high(n,x)) p2: quicksort#(add(n,x)) -> quicksort#(low(n,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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: low(n,nil()) -> nil() r11: low(n,add(m,x)) -> if_low(le(m,n),n,add(m,x)) r12: if_low(true(),n,add(m,x)) -> add(m,low(n,x)) r13: if_low(false(),n,add(m,x)) -> low(n,x) r14: high(n,nil()) -> nil() r15: high(n,add(m,x)) -> if_high(le(m,n),n,add(m,x)) r16: if_high(true(),n,add(m,x)) -> high(n,x) r17: if_high(false(),n,add(m,x)) -> add(m,high(n,x)) r18: quicksort(nil()) -> nil() r19: quicksort(add(n,x)) -> app(quicksort(low(n,x)),add(n,quicksort(high(n,x)))) The set of usable rules consists of r5, r6, r7, r10, r11, r12, r13, r14, r15, r16, r17 Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: quicksort#_A(x1) = max{9, x1 + 2} add_A(x1,x2) = x2 + 14 high_A(x1,x2) = x2 + 12 low_A(x1,x2) = x2 + 3 le_A(x1,x2) = 22 |0|_A = 22 true_A = 21 s_A(x1) = x1 + 13 false_A = 12 if_low_A(x1,x2,x3) = max{10, x1 - 5, x3 + 3} if_high_A(x1,x2,x3) = max{x1 - 2, x3 + 12} nil_A = 0 precedence: le > low = |0| = true = if_low > high > if_high > add > quicksort# = s = false = nil partial status: pi(quicksort#) = [1] pi(add) = [2] pi(high) = [] pi(low) = [] pi(le) = [] pi(|0|) = [] pi(true) = [] pi(s) = [1] pi(false) = [] pi(if_low) = [] pi(if_high) = [] pi(nil) = [] The next rules are strictly ordered: p2 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: quicksort#(add(n,x)) -> quicksort#(high(n,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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: low(n,nil()) -> nil() r11: low(n,add(m,x)) -> if_low(le(m,n),n,add(m,x)) r12: if_low(true(),n,add(m,x)) -> add(m,low(n,x)) r13: if_low(false(),n,add(m,x)) -> low(n,x) r14: high(n,nil()) -> nil() r15: high(n,add(m,x)) -> if_high(le(m,n),n,add(m,x)) r16: if_high(true(),n,add(m,x)) -> high(n,x) r17: if_high(false(),n,add(m,x)) -> add(m,high(n,x)) r18: quicksort(nil()) -> nil() r19: quicksort(add(n,x)) -> app(quicksort(low(n,x)),add(n,quicksort(high(n,x)))) The estimated dependency graph contains the following SCCs: {p1} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: quicksort#(add(n,x)) -> quicksort#(high(n,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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: low(n,nil()) -> nil() r11: low(n,add(m,x)) -> if_low(le(m,n),n,add(m,x)) r12: if_low(true(),n,add(m,x)) -> add(m,low(n,x)) r13: if_low(false(),n,add(m,x)) -> low(n,x) r14: high(n,nil()) -> nil() r15: high(n,add(m,x)) -> if_high(le(m,n),n,add(m,x)) r16: if_high(true(),n,add(m,x)) -> high(n,x) r17: if_high(false(),n,add(m,x)) -> add(m,high(n,x)) r18: quicksort(nil()) -> nil() r19: quicksort(add(n,x)) -> app(quicksort(low(n,x)),add(n,quicksort(high(n,x)))) The set of usable rules consists of r5, r6, r7, r14, r15, r16, r17 Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: quicksort#_A(x1) = x1 + 2 add_A(x1,x2) = max{6, x1 + 4, x2 + 4} high_A(x1,x2) = x2 + 1 le_A(x1,x2) = max{x1 - 11, x2 + 12} |0|_A = 10 true_A = 11 s_A(x1) = max{21, x1 + 10} false_A = 9 if_high_A(x1,x2,x3) = x3 + 1 nil_A = 1 precedence: quicksort# = add = high = le = |0| = true = s = false = if_high = nil partial status: pi(quicksort#) = [1] pi(add) = [1, 2] pi(high) = [2] pi(le) = [] pi(|0|) = [] pi(true) = [] pi(s) = [1] pi(false) = [] pi(if_high) = [3] pi(nil) = [] The next rules are strictly ordered: p1 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: if_high#(false(),n,add(m,x)) -> high#(n,x) p2: high#(n,add(m,x)) -> if_high#(le(m,n),n,add(m,x)) p3: if_high#(true(),n,add(m,x)) -> high#(n,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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: low(n,nil()) -> nil() r11: low(n,add(m,x)) -> if_low(le(m,n),n,add(m,x)) r12: if_low(true(),n,add(m,x)) -> add(m,low(n,x)) r13: if_low(false(),n,add(m,x)) -> low(n,x) r14: high(n,nil()) -> nil() r15: high(n,add(m,x)) -> if_high(le(m,n),n,add(m,x)) r16: if_high(true(),n,add(m,x)) -> high(n,x) r17: if_high(false(),n,add(m,x)) -> add(m,high(n,x)) r18: quicksort(nil()) -> nil() r19: quicksort(add(n,x)) -> app(quicksort(low(n,x)),add(n,quicksort(high(n,x)))) The set of usable rules consists of r5, r6, r7 Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: if_high#_A(x1,x2,x3) = max{x1 + 7, x2 + 3, x3} false_A = 1 add_A(x1,x2) = max{9, x2 + 8} high#_A(x1,x2) = max{x1 + 3, x2} le_A(x1,x2) = max{2, x2 - 4} true_A = 1 |0|_A = 0 s_A(x1) = max{6, x1 + 2} precedence: if_high# = false = add = high# = le > true > |0| = s partial status: pi(if_high#) = [3] pi(false) = [] pi(add) = [2] pi(high#) = [2] pi(le) = [] pi(true) = [] pi(|0|) = [] pi(s) = [1] The next rules are strictly ordered: p3 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: if_high#(false(),n,add(m,x)) -> high#(n,x) p2: high#(n,add(m,x)) -> if_high#(le(m,n),n,add(m,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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: low(n,nil()) -> nil() r11: low(n,add(m,x)) -> if_low(le(m,n),n,add(m,x)) r12: if_low(true(),n,add(m,x)) -> add(m,low(n,x)) r13: if_low(false(),n,add(m,x)) -> low(n,x) r14: high(n,nil()) -> nil() r15: high(n,add(m,x)) -> if_high(le(m,n),n,add(m,x)) r16: if_high(true(),n,add(m,x)) -> high(n,x) r17: if_high(false(),n,add(m,x)) -> add(m,high(n,x)) r18: quicksort(nil()) -> nil() r19: quicksort(add(n,x)) -> app(quicksort(low(n,x)),add(n,quicksort(high(n,x)))) The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: if_high#(false(),n,add(m,x)) -> high#(n,x) p2: high#(n,add(m,x)) -> if_high#(le(m,n),n,add(m,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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: low(n,nil()) -> nil() r11: low(n,add(m,x)) -> if_low(le(m,n),n,add(m,x)) r12: if_low(true(),n,add(m,x)) -> add(m,low(n,x)) r13: if_low(false(),n,add(m,x)) -> low(n,x) r14: high(n,nil()) -> nil() r15: high(n,add(m,x)) -> if_high(le(m,n),n,add(m,x)) r16: if_high(true(),n,add(m,x)) -> high(n,x) r17: if_high(false(),n,add(m,x)) -> add(m,high(n,x)) r18: quicksort(nil()) -> nil() r19: quicksort(add(n,x)) -> app(quicksort(low(n,x)),add(n,quicksort(high(n,x)))) The set of usable rules consists of r5, r6, r7 Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: if_high#_A(x1,x2,x3) = max{3, x1 - 10, x3 + 1} false_A = 1 add_A(x1,x2) = max{5, x1 - 3, x2 + 2} high#_A(x1,x2) = x2 + 2 le_A(x1,x2) = 8 |0|_A = 0 true_A = 1 s_A(x1) = max{12, x1 + 2} precedence: if_high# = false = add = high# = le = |0| = true = s partial status: pi(if_high#) = [] pi(false) = [] pi(add) = [2] pi(high#) = [] pi(le) = [] pi(|0|) = [] pi(true) = [] pi(s) = [1] The next rules are strictly ordered: p1 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: high#(n,add(m,x)) -> if_high#(le(m,n),n,add(m,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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: low(n,nil()) -> nil() r11: low(n,add(m,x)) -> if_low(le(m,n),n,add(m,x)) r12: if_low(true(),n,add(m,x)) -> add(m,low(n,x)) r13: if_low(false(),n,add(m,x)) -> low(n,x) r14: high(n,nil()) -> nil() r15: high(n,add(m,x)) -> if_high(le(m,n),n,add(m,x)) r16: if_high(true(),n,add(m,x)) -> high(n,x) r17: if_high(false(),n,add(m,x)) -> add(m,high(n,x)) r18: quicksort(nil()) -> nil() r19: quicksort(add(n,x)) -> app(quicksort(low(n,x)),add(n,quicksort(high(n,x)))) The estimated dependency graph contains the following SCCs: (no SCCs) -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: if_low#(false(),n,add(m,x)) -> low#(n,x) p2: low#(n,add(m,x)) -> if_low#(le(m,n),n,add(m,x)) p3: if_low#(true(),n,add(m,x)) -> low#(n,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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: low(n,nil()) -> nil() r11: low(n,add(m,x)) -> if_low(le(m,n),n,add(m,x)) r12: if_low(true(),n,add(m,x)) -> add(m,low(n,x)) r13: if_low(false(),n,add(m,x)) -> low(n,x) r14: high(n,nil()) -> nil() r15: high(n,add(m,x)) -> if_high(le(m,n),n,add(m,x)) r16: if_high(true(),n,add(m,x)) -> high(n,x) r17: if_high(false(),n,add(m,x)) -> add(m,high(n,x)) r18: quicksort(nil()) -> nil() r19: quicksort(add(n,x)) -> app(quicksort(low(n,x)),add(n,quicksort(high(n,x)))) The set of usable rules consists of r5, r6, r7 Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: if_low#_A(x1,x2,x3) = max{x1 + 8, x2 + 4, x3} false_A = 2 add_A(x1,x2) = max{11, x1 + 4, x2 + 10} low#_A(x1,x2) = max{x1 + 4, x2} le_A(x1,x2) = max{3, x1 - 4, x2 - 4} true_A = 0 |0|_A = 1 s_A(x1) = x1 + 3 precedence: if_low# = false = add = low# = le > true > |0| = s partial status: pi(if_low#) = [3] pi(false) = [] pi(add) = [2] pi(low#) = [2] pi(le) = [] pi(true) = [] pi(|0|) = [] pi(s) = [1] The next rules are strictly ordered: p3 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: if_low#(false(),n,add(m,x)) -> low#(n,x) p2: low#(n,add(m,x)) -> if_low#(le(m,n),n,add(m,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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: low(n,nil()) -> nil() r11: low(n,add(m,x)) -> if_low(le(m,n),n,add(m,x)) r12: if_low(true(),n,add(m,x)) -> add(m,low(n,x)) r13: if_low(false(),n,add(m,x)) -> low(n,x) r14: high(n,nil()) -> nil() r15: high(n,add(m,x)) -> if_high(le(m,n),n,add(m,x)) r16: if_high(true(),n,add(m,x)) -> high(n,x) r17: if_high(false(),n,add(m,x)) -> add(m,high(n,x)) r18: quicksort(nil()) -> nil() r19: quicksort(add(n,x)) -> app(quicksort(low(n,x)),add(n,quicksort(high(n,x)))) The estimated dependency graph contains the following SCCs: {p1, p2} -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: if_low#(false(),n,add(m,x)) -> low#(n,x) p2: low#(n,add(m,x)) -> if_low#(le(m,n),n,add(m,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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: low(n,nil()) -> nil() r11: low(n,add(m,x)) -> if_low(le(m,n),n,add(m,x)) r12: if_low(true(),n,add(m,x)) -> add(m,low(n,x)) r13: if_low(false(),n,add(m,x)) -> low(n,x) r14: high(n,nil()) -> nil() r15: high(n,add(m,x)) -> if_high(le(m,n),n,add(m,x)) r16: if_high(true(),n,add(m,x)) -> high(n,x) r17: if_high(false(),n,add(m,x)) -> add(m,high(n,x)) r18: quicksort(nil()) -> nil() r19: quicksort(add(n,x)) -> app(quicksort(low(n,x)),add(n,quicksort(high(n,x)))) The set of usable rules consists of r5, r6, r7 Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: if_low#_A(x1,x2,x3) = max{3, x1 - 10, x3 + 1} false_A = 1 add_A(x1,x2) = max{5, x1 - 3, x2 + 2} low#_A(x1,x2) = x2 + 2 le_A(x1,x2) = 8 |0|_A = 0 true_A = 1 s_A(x1) = max{12, x1 + 2} precedence: if_low# = false = add = low# = le = |0| = true = s partial status: pi(if_low#) = [] pi(false) = [] pi(add) = [2] pi(low#) = [] pi(le) = [] pi(|0|) = [] pi(true) = [] pi(s) = [1] The next rules are strictly ordered: p1 We remove them from the problem. -- SCC decomposition. Consider the dependency pair problem (P, R), where P consists of p1: low#(n,add(m,x)) -> if_low#(le(m,n),n,add(m,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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: low(n,nil()) -> nil() r11: low(n,add(m,x)) -> if_low(le(m,n),n,add(m,x)) r12: if_low(true(),n,add(m,x)) -> add(m,low(n,x)) r13: if_low(false(),n,add(m,x)) -> low(n,x) r14: high(n,nil()) -> nil() r15: high(n,add(m,x)) -> if_high(le(m,n),n,add(m,x)) r16: if_high(true(),n,add(m,x)) -> high(n,x) r17: if_high(false(),n,add(m,x)) -> add(m,high(n,x)) r18: quicksort(nil()) -> nil() r19: quicksort(add(n,x)) -> app(quicksort(low(n,x)),add(n,quicksort(high(n,x)))) The estimated dependency graph contains the following SCCs: (no SCCs) -- Reduction pair. Consider the dependency pair problem (P, R), where P consists of p1: le#(s(x),s(y)) -> le#(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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: low(n,nil()) -> nil() r11: low(n,add(m,x)) -> if_low(le(m,n),n,add(m,x)) r12: if_low(true(),n,add(m,x)) -> add(m,low(n,x)) r13: if_low(false(),n,add(m,x)) -> low(n,x) r14: high(n,nil()) -> nil() r15: high(n,add(m,x)) -> if_high(le(m,n),n,add(m,x)) r16: if_high(true(),n,add(m,x)) -> high(n,x) r17: if_high(false(),n,add(m,x)) -> add(m,high(n,x)) r18: quicksort(nil()) -> nil() r19: quicksort(add(n,x)) -> app(quicksort(low(n,x)),add(n,quicksort(high(n,x)))) The set of usable rules consists of (no rules) Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: le#_A(x1,x2) = max{0, x1 - 2, x2 - 2} s_A(x1) = max{3, x1 + 1} precedence: le# = s partial status: pi(le#) = [] pi(s) = [] The next rules are strictly ordered: p1 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#(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: le(|0|(),y) -> true() r6: le(s(x),|0|()) -> false() r7: le(s(x),s(y)) -> le(x,y) r8: app(nil(),y) -> y r9: app(add(n,x),y) -> add(n,app(x,y)) r10: low(n,nil()) -> nil() r11: low(n,add(m,x)) -> if_low(le(m,n),n,add(m,x)) r12: if_low(true(),n,add(m,x)) -> add(m,low(n,x)) r13: if_low(false(),n,add(m,x)) -> low(n,x) r14: high(n,nil()) -> nil() r15: high(n,add(m,x)) -> if_high(le(m,n),n,add(m,x)) r16: if_high(true(),n,add(m,x)) -> high(n,x) r17: if_high(false(),n,add(m,x)) -> add(m,high(n,x)) r18: quicksort(nil()) -> nil() r19: quicksort(add(n,x)) -> app(quicksort(low(n,x)),add(n,quicksort(high(n,x)))) The set of usable rules consists of (no rules) Take the reduction pair: weighted path order base order: max/plus interpretations on natural numbers: app#_A(x1,x2) = max{x1 + 1, x2 + 1} add_A(x1,x2) = x2 precedence: app# = add partial status: pi(app#) = [1] pi(add) = [2] The next rules are strictly ordered: p1 We remove them from the problem. Then no dependency pair remains.