WORST_CASE(?,O(n^2)) * Step 1: DependencyPairs WORST_CASE(?,O(n^2)) + Considered Problem: - Strict TRS: @(dd(x,xs),ys) -> dd(x,@(xs,ys)) @(nil(),xs) -> xs rev(dd(x,xs)) -> @(rev(xs),dd(x,nil())) rev(nil()) -> nil() - Signature: {@/2,rev/1} / {dd/2,nil/0} - Obligation: innermost runtime complexity wrt. defined symbols {@,rev} and constructors {dd,nil} + Applied Processor: DependencyPairs {dpKind_ = DT} + Details: We add the following dependency tuples: Strict DPs @#(dd(x,xs),ys) -> c_1(@#(xs,ys)) @#(nil(),xs) -> c_2() rev#(dd(x,xs)) -> c_3(@#(rev(xs),dd(x,nil())),rev#(xs)) rev#(nil()) -> c_4() Weak DPs and mark the set of starting terms. * Step 2: PredecessorEstimation WORST_CASE(?,O(n^2)) + Considered Problem: - Strict DPs: @#(dd(x,xs),ys) -> c_1(@#(xs,ys)) @#(nil(),xs) -> c_2() rev#(dd(x,xs)) -> c_3(@#(rev(xs),dd(x,nil())),rev#(xs)) rev#(nil()) -> c_4() - Weak TRS: @(dd(x,xs),ys) -> dd(x,@(xs,ys)) @(nil(),xs) -> xs rev(dd(x,xs)) -> @(rev(xs),dd(x,nil())) rev(nil()) -> nil() - Signature: {@/2,rev/1,@#/2,rev#/1} / {dd/2,nil/0,c_1/1,c_2/0,c_3/2,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {@#,rev#} and constructors {dd,nil} + Applied Processor: PredecessorEstimation {onSelection = all simple predecessor estimation selector} + Details: We estimate the number of application of {2,4} by application of Pre({2,4}) = {1,3}. Here rules are labelled as follows: 1: @#(dd(x,xs),ys) -> c_1(@#(xs,ys)) 2: @#(nil(),xs) -> c_2() 3: rev#(dd(x,xs)) -> c_3(@#(rev(xs),dd(x,nil())),rev#(xs)) 4: rev#(nil()) -> c_4() * Step 3: RemoveWeakSuffixes WORST_CASE(?,O(n^2)) + Considered Problem: - Strict DPs: @#(dd(x,xs),ys) -> c_1(@#(xs,ys)) rev#(dd(x,xs)) -> c_3(@#(rev(xs),dd(x,nil())),rev#(xs)) - Weak DPs: @#(nil(),xs) -> c_2() rev#(nil()) -> c_4() - Weak TRS: @(dd(x,xs),ys) -> dd(x,@(xs,ys)) @(nil(),xs) -> xs rev(dd(x,xs)) -> @(rev(xs),dd(x,nil())) rev(nil()) -> nil() - Signature: {@/2,rev/1,@#/2,rev#/1} / {dd/2,nil/0,c_1/1,c_2/0,c_3/2,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {@#,rev#} and constructors {dd,nil} + Applied Processor: RemoveWeakSuffixes + Details: Consider the dependency graph 1:S:@#(dd(x,xs),ys) -> c_1(@#(xs,ys)) -->_1 @#(nil(),xs) -> c_2():3 -->_1 @#(dd(x,xs),ys) -> c_1(@#(xs,ys)):1 2:S:rev#(dd(x,xs)) -> c_3(@#(rev(xs),dd(x,nil())),rev#(xs)) -->_2 rev#(nil()) -> c_4():4 -->_1 @#(nil(),xs) -> c_2():3 -->_2 rev#(dd(x,xs)) -> c_3(@#(rev(xs),dd(x,nil())),rev#(xs)):2 -->_1 @#(dd(x,xs),ys) -> c_1(@#(xs,ys)):1 3:W:@#(nil(),xs) -> c_2() 4:W:rev#(nil()) -> c_4() The following weak DPs constitute a sub-graph of the DG that is closed under successors. The DPs are removed. 4: rev#(nil()) -> c_4() 3: @#(nil(),xs) -> c_2() * Step 4: DecomposeDG WORST_CASE(?,O(n^2)) + Considered Problem: - Strict DPs: @#(dd(x,xs),ys) -> c_1(@#(xs,ys)) rev#(dd(x,xs)) -> c_3(@#(rev(xs),dd(x,nil())),rev#(xs)) - Weak TRS: @(dd(x,xs),ys) -> dd(x,@(xs,ys)) @(nil(),xs) -> xs rev(dd(x,xs)) -> @(rev(xs),dd(x,nil())) rev(nil()) -> nil() - Signature: {@/2,rev/1,@#/2,rev#/1} / {dd/2,nil/0,c_1/1,c_2/0,c_3/2,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {@#,rev#} and constructors {dd,nil} + Applied Processor: DecomposeDG {onSelection = all below first cut in WDG, onUpper = Nothing, onLower = Nothing} + Details: We decompose the input problem according to the dependency graph into the upper component rev#(dd(x,xs)) -> c_3(@#(rev(xs),dd(x,nil())),rev#(xs)) and a lower component @#(dd(x,xs),ys) -> c_1(@#(xs,ys)) Further, following extension rules are added to the lower component. rev#(dd(x,xs)) -> @#(rev(xs),dd(x,nil())) rev#(dd(x,xs)) -> rev#(xs) ** Step 4.a:1: SimplifyRHS WORST_CASE(?,O(n^1)) + Considered Problem: - Strict DPs: rev#(dd(x,xs)) -> c_3(@#(rev(xs),dd(x,nil())),rev#(xs)) - Weak TRS: @(dd(x,xs),ys) -> dd(x,@(xs,ys)) @(nil(),xs) -> xs rev(dd(x,xs)) -> @(rev(xs),dd(x,nil())) rev(nil()) -> nil() - Signature: {@/2,rev/1,@#/2,rev#/1} / {dd/2,nil/0,c_1/1,c_2/0,c_3/2,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {@#,rev#} and constructors {dd,nil} + Applied Processor: SimplifyRHS + Details: Consider the dependency graph 1:S:rev#(dd(x,xs)) -> c_3(@#(rev(xs),dd(x,nil())),rev#(xs)) -->_2 rev#(dd(x,xs)) -> c_3(@#(rev(xs),dd(x,nil())),rev#(xs)):1 Due to missing edges in the depndency graph, the right-hand sides of following rules could be simplified: rev#(dd(x,xs)) -> c_3(rev#(xs)) ** Step 4.a:2: UsableRules WORST_CASE(?,O(n^1)) + Considered Problem: - Strict DPs: rev#(dd(x,xs)) -> c_3(rev#(xs)) - Weak TRS: @(dd(x,xs),ys) -> dd(x,@(xs,ys)) @(nil(),xs) -> xs rev(dd(x,xs)) -> @(rev(xs),dd(x,nil())) rev(nil()) -> nil() - Signature: {@/2,rev/1,@#/2,rev#/1} / {dd/2,nil/0,c_1/1,c_2/0,c_3/1,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {@#,rev#} and constructors {dd,nil} + Applied Processor: UsableRules + Details: We replace rewrite rules by usable rules: rev#(dd(x,xs)) -> c_3(rev#(xs)) ** Step 4.a:3: WeightGap WORST_CASE(?,O(n^1)) + Considered Problem: - Strict DPs: rev#(dd(x,xs)) -> c_3(rev#(xs)) - Signature: {@/2,rev/1,@#/2,rev#/1} / {dd/2,nil/0,c_1/1,c_2/0,c_3/1,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {@#,rev#} and constructors {dd,nil} + Applied Processor: WeightGap {wgDimension = 1, wgDegree = 1, wgKind = Algebraic, wgUArgs = UArgs, wgOn = WgOnAny} + Details: The weightgap principle applies using the following constant growth matrix-interpretation: We apply a matrix interpretation of kind constructor based matrix interpretation: The following argument positions are considered usable: uargs(c_3) = {1} Following symbols are considered usable: all TcT has computed the following interpretation: p(@) = [0] p(dd) = [1] x1 + [1] x2 + [9] p(nil) = [0] p(rev) = [0] p(@#) = [0] p(rev#) = [2] x1 + [11] p(c_1) = [0] p(c_2) = [0] p(c_3) = [1] x1 + [0] p(c_4) = [0] Following rules are strictly oriented: rev#(dd(x,xs)) = [2] x + [2] xs + [29] > [2] xs + [11] = c_3(rev#(xs)) Following rules are (at-least) weakly oriented: Further, it can be verified that all rules not oriented are covered by the weightgap condition. ** Step 4.a:4: EmptyProcessor WORST_CASE(?,O(1)) + Considered Problem: - Weak DPs: rev#(dd(x,xs)) -> c_3(rev#(xs)) - Signature: {@/2,rev/1,@#/2,rev#/1} / {dd/2,nil/0,c_1/1,c_2/0,c_3/1,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {@#,rev#} and constructors {dd,nil} + Applied Processor: EmptyProcessor + Details: The problem is already closed. The intended complexity is O(1). ** Step 4.b:1: NaturalMI WORST_CASE(?,O(n^1)) + Considered Problem: - Strict DPs: @#(dd(x,xs),ys) -> c_1(@#(xs,ys)) - Weak DPs: rev#(dd(x,xs)) -> @#(rev(xs),dd(x,nil())) rev#(dd(x,xs)) -> rev#(xs) - Weak TRS: @(dd(x,xs),ys) -> dd(x,@(xs,ys)) @(nil(),xs) -> xs rev(dd(x,xs)) -> @(rev(xs),dd(x,nil())) rev(nil()) -> nil() - Signature: {@/2,rev/1,@#/2,rev#/1} / {dd/2,nil/0,c_1/1,c_2/0,c_3/2,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {@#,rev#} and constructors {dd,nil} + Applied Processor: NaturalMI {miDimension = 1, miDegree = 1, miKind = Algebraic, uargs = UArgs, urules = URules, selector = Just any strict-rules} + Details: We apply a matrix interpretation of kind constructor based matrix interpretation: The following argument positions are considered usable: uargs(c_1) = {1} Following symbols are considered usable: {@,rev,@#,rev#} TcT has computed the following interpretation: p(@) = [1] x1 + [1] x2 + [0] p(dd) = [1] x1 + [1] x2 + [2] p(nil) = [0] p(rev) = [2] x1 + [1] p(@#) = [1] x1 + [2] x2 + [0] p(rev#) = [2] x1 + [2] p(c_1) = [1] x1 + [0] p(c_2) = [1] p(c_3) = [8] x2 + [1] p(c_4) = [1] Following rules are strictly oriented: @#(dd(x,xs),ys) = [1] x + [1] xs + [2] ys + [2] > [1] xs + [2] ys + [0] = c_1(@#(xs,ys)) Following rules are (at-least) weakly oriented: rev#(dd(x,xs)) = [2] x + [2] xs + [6] >= [2] x + [2] xs + [5] = @#(rev(xs),dd(x,nil())) rev#(dd(x,xs)) = [2] x + [2] xs + [6] >= [2] xs + [2] = rev#(xs) @(dd(x,xs),ys) = [1] x + [1] xs + [1] ys + [2] >= [1] x + [1] xs + [1] ys + [2] = dd(x,@(xs,ys)) @(nil(),xs) = [1] xs + [0] >= [1] xs + [0] = xs rev(dd(x,xs)) = [2] x + [2] xs + [5] >= [1] x + [2] xs + [3] = @(rev(xs),dd(x,nil())) rev(nil()) = [1] >= [0] = nil() ** Step 4.b:2: EmptyProcessor WORST_CASE(?,O(1)) + Considered Problem: - Weak DPs: @#(dd(x,xs),ys) -> c_1(@#(xs,ys)) rev#(dd(x,xs)) -> @#(rev(xs),dd(x,nil())) rev#(dd(x,xs)) -> rev#(xs) - Weak TRS: @(dd(x,xs),ys) -> dd(x,@(xs,ys)) @(nil(),xs) -> xs rev(dd(x,xs)) -> @(rev(xs),dd(x,nil())) rev(nil()) -> nil() - Signature: {@/2,rev/1,@#/2,rev#/1} / {dd/2,nil/0,c_1/1,c_2/0,c_3/2,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {@#,rev#} and constructors {dd,nil} + Applied Processor: EmptyProcessor + Details: The problem is already closed. The intended complexity is O(1). WORST_CASE(?,O(n^2))