MAYBE * Step 1: DependencyPairs MAYBE + Considered Problem: - Strict TRS: purge(.(x,y)) -> .(x,purge(remove(x,y))) purge(nil()) -> nil() remove(x,.(y,z)) -> if(=(x,y),remove(x,z),.(y,remove(x,z))) remove(x,nil()) -> nil() - Signature: {purge/1,remove/2} / {./2,=/2,if/3,nil/0} - Obligation: innermost runtime complexity wrt. defined symbols {purge,remove} and constructors {.,=,if,nil} + Applied Processor: DependencyPairs {dpKind_ = DT} + Details: We add the following dependency tuples: Strict DPs purge#(.(x,y)) -> c_1(purge#(remove(x,y)),remove#(x,y)) purge#(nil()) -> c_2() remove#(x,.(y,z)) -> c_3(remove#(x,z),remove#(x,z)) remove#(x,nil()) -> c_4() Weak DPs and mark the set of starting terms. * Step 2: UsableRules MAYBE + Considered Problem: - Strict DPs: purge#(.(x,y)) -> c_1(purge#(remove(x,y)),remove#(x,y)) purge#(nil()) -> c_2() remove#(x,.(y,z)) -> c_3(remove#(x,z),remove#(x,z)) remove#(x,nil()) -> c_4() - Weak TRS: purge(.(x,y)) -> .(x,purge(remove(x,y))) purge(nil()) -> nil() remove(x,.(y,z)) -> if(=(x,y),remove(x,z),.(y,remove(x,z))) remove(x,nil()) -> nil() - Signature: {purge/1,remove/2,purge#/1,remove#/2} / {./2,=/2,if/3,nil/0,c_1/2,c_2/0,c_3/2,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {purge#,remove#} and constructors {.,=,if,nil} + Applied Processor: UsableRules + Details: We replace rewrite rules by usable rules: remove(x,.(y,z)) -> if(=(x,y),remove(x,z),.(y,remove(x,z))) remove(x,nil()) -> nil() purge#(.(x,y)) -> c_1(purge#(remove(x,y)),remove#(x,y)) purge#(nil()) -> c_2() remove#(x,.(y,z)) -> c_3(remove#(x,z),remove#(x,z)) remove#(x,nil()) -> c_4() * Step 3: PredecessorEstimation MAYBE + Considered Problem: - Strict DPs: purge#(.(x,y)) -> c_1(purge#(remove(x,y)),remove#(x,y)) purge#(nil()) -> c_2() remove#(x,.(y,z)) -> c_3(remove#(x,z),remove#(x,z)) remove#(x,nil()) -> c_4() - Weak TRS: remove(x,.(y,z)) -> if(=(x,y),remove(x,z),.(y,remove(x,z))) remove(x,nil()) -> nil() - Signature: {purge/1,remove/2,purge#/1,remove#/2} / {./2,=/2,if/3,nil/0,c_1/2,c_2/0,c_3/2,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {purge#,remove#} and constructors {.,=,if,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: purge#(.(x,y)) -> c_1(purge#(remove(x,y)),remove#(x,y)) 2: purge#(nil()) -> c_2() 3: remove#(x,.(y,z)) -> c_3(remove#(x,z),remove#(x,z)) 4: remove#(x,nil()) -> c_4() * Step 4: RemoveWeakSuffixes MAYBE + Considered Problem: - Strict DPs: purge#(.(x,y)) -> c_1(purge#(remove(x,y)),remove#(x,y)) remove#(x,.(y,z)) -> c_3(remove#(x,z),remove#(x,z)) - Weak DPs: purge#(nil()) -> c_2() remove#(x,nil()) -> c_4() - Weak TRS: remove(x,.(y,z)) -> if(=(x,y),remove(x,z),.(y,remove(x,z))) remove(x,nil()) -> nil() - Signature: {purge/1,remove/2,purge#/1,remove#/2} / {./2,=/2,if/3,nil/0,c_1/2,c_2/0,c_3/2,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {purge#,remove#} and constructors {.,=,if,nil} + Applied Processor: RemoveWeakSuffixes + Details: Consider the dependency graph 1:S:purge#(.(x,y)) -> c_1(purge#(remove(x,y)),remove#(x,y)) -->_2 remove#(x,.(y,z)) -> c_3(remove#(x,z),remove#(x,z)):2 -->_2 remove#(x,nil()) -> c_4():4 -->_1 purge#(nil()) -> c_2():3 -->_1 purge#(.(x,y)) -> c_1(purge#(remove(x,y)),remove#(x,y)):1 2:S:remove#(x,.(y,z)) -> c_3(remove#(x,z),remove#(x,z)) -->_2 remove#(x,nil()) -> c_4():4 -->_1 remove#(x,nil()) -> c_4():4 -->_2 remove#(x,.(y,z)) -> c_3(remove#(x,z),remove#(x,z)):2 -->_1 remove#(x,.(y,z)) -> c_3(remove#(x,z),remove#(x,z)):2 3:W:purge#(nil()) -> c_2() 4:W:remove#(x,nil()) -> c_4() The following weak DPs constitute a sub-graph of the DG that is closed under successors. The DPs are removed. 3: purge#(nil()) -> c_2() 4: remove#(x,nil()) -> c_4() * Step 5: DecomposeDG MAYBE + Considered Problem: - Strict DPs: purge#(.(x,y)) -> c_1(purge#(remove(x,y)),remove#(x,y)) remove#(x,.(y,z)) -> c_3(remove#(x,z),remove#(x,z)) - Weak TRS: remove(x,.(y,z)) -> if(=(x,y),remove(x,z),.(y,remove(x,z))) remove(x,nil()) -> nil() - Signature: {purge/1,remove/2,purge#/1,remove#/2} / {./2,=/2,if/3,nil/0,c_1/2,c_2/0,c_3/2,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {purge#,remove#} and constructors {.,=,if,nil} + Applied Processor: DecomposeDG {onSelection = all below first cut in WDG, onUpper = Just someStrategy, onLower = Nothing} + Details: We decompose the input problem according to the dependency graph into the upper component purge#(.(x,y)) -> c_1(purge#(remove(x,y)),remove#(x,y)) and a lower component remove#(x,.(y,z)) -> c_3(remove#(x,z),remove#(x,z)) Further, following extension rules are added to the lower component. purge#(.(x,y)) -> purge#(remove(x,y)) purge#(.(x,y)) -> remove#(x,y) ** Step 5.a:1: PredecessorEstimationCP WORST_CASE(?,O(n^1)) + Considered Problem: - Strict DPs: purge#(.(x,y)) -> c_1(purge#(remove(x,y)),remove#(x,y)) - Weak TRS: remove(x,.(y,z)) -> if(=(x,y),remove(x,z),.(y,remove(x,z))) remove(x,nil()) -> nil() - Signature: {purge/1,remove/2,purge#/1,remove#/2} / {./2,=/2,if/3,nil/0,c_1/2,c_2/0,c_3/2,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {purge#,remove#} and constructors {.,=,if,nil} + Applied Processor: PredecessorEstimationCP {onSelectionCP = any intersect of rules of CDG leaf and strict-rules, withComplexityPair = NaturalMI {miDimension = 1, miDegree = 1, miKind = Algebraic, uargs = UArgs, urules = URules, selector = Nothing}} + Details: We first use the processor NaturalMI {miDimension = 1, miDegree = 1, miKind = Algebraic, uargs = UArgs, urules = URules, selector = Nothing} to orient following rules strictly: 1: purge#(.(x,y)) -> c_1(purge#(remove(x,y)),remove#(x,y)) The strictly oriented rules are moved into the weak component. *** Step 5.a:1.a:1: NaturalMI WORST_CASE(?,O(n^1)) + Considered Problem: - Strict DPs: purge#(.(x,y)) -> c_1(purge#(remove(x,y)),remove#(x,y)) - Weak TRS: remove(x,.(y,z)) -> if(=(x,y),remove(x,z),.(y,remove(x,z))) remove(x,nil()) -> nil() - Signature: {purge/1,remove/2,purge#/1,remove#/2} / {./2,=/2,if/3,nil/0,c_1/2,c_2/0,c_3/2,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {purge#,remove#} and constructors {.,=,if,nil} + Applied Processor: NaturalMI {miDimension = 1, miDegree = 1, miKind = Algebraic, uargs = UArgs, urules = URules, selector = Just first alternative for predecessorEstimation on any intersect of rules of CDG leaf and 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: {remove,purge#,remove#} TcT has computed the following interpretation: p(.) = [5] p(=) = [1] x1 + [8] p(if) = [1] x2 + [0] p(nil) = [0] p(purge) = [1] x1 + [2] p(remove) = [0] p(purge#) = [5] x1 + [4] p(remove#) = [4] p(c_1) = [4] x1 + [1] x2 + [8] p(c_2) = [1] p(c_3) = [1] p(c_4) = [0] Following rules are strictly oriented: purge#(.(x,y)) = [29] > [28] = c_1(purge#(remove(x,y)),remove#(x,y)) Following rules are (at-least) weakly oriented: remove(x,.(y,z)) = [0] >= [0] = if(=(x,y),remove(x,z),.(y,remove(x,z))) remove(x,nil()) = [0] >= [0] = nil() *** Step 5.a:1.a:2: Assumption WORST_CASE(?,O(1)) + Considered Problem: - Weak DPs: purge#(.(x,y)) -> c_1(purge#(remove(x,y)),remove#(x,y)) - Weak TRS: remove(x,.(y,z)) -> if(=(x,y),remove(x,z),.(y,remove(x,z))) remove(x,nil()) -> nil() - Signature: {purge/1,remove/2,purge#/1,remove#/2} / {./2,=/2,if/3,nil/0,c_1/2,c_2/0,c_3/2,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {purge#,remove#} and constructors {.,=,if,nil} + Applied Processor: Assumption {assumed = Certificate {spaceUB = Unknown, spaceLB = Unknown, timeUB = Poly (Just 0), timeLB = Unknown}} + Details: () *** Step 5.a:1.b:1: RemoveWeakSuffixes WORST_CASE(?,O(1)) + Considered Problem: - Weak DPs: purge#(.(x,y)) -> c_1(purge#(remove(x,y)),remove#(x,y)) - Weak TRS: remove(x,.(y,z)) -> if(=(x,y),remove(x,z),.(y,remove(x,z))) remove(x,nil()) -> nil() - Signature: {purge/1,remove/2,purge#/1,remove#/2} / {./2,=/2,if/3,nil/0,c_1/2,c_2/0,c_3/2,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {purge#,remove#} and constructors {.,=,if,nil} + Applied Processor: RemoveWeakSuffixes + Details: Consider the dependency graph 1:W:purge#(.(x,y)) -> c_1(purge#(remove(x,y)),remove#(x,y)) -->_1 purge#(.(x,y)) -> c_1(purge#(remove(x,y)),remove#(x,y)):1 The following weak DPs constitute a sub-graph of the DG that is closed under successors. The DPs are removed. 1: purge#(.(x,y)) -> c_1(purge#(remove(x,y)),remove#(x,y)) *** Step 5.a:1.b:2: EmptyProcessor WORST_CASE(?,O(1)) + Considered Problem: - Weak TRS: remove(x,.(y,z)) -> if(=(x,y),remove(x,z),.(y,remove(x,z))) remove(x,nil()) -> nil() - Signature: {purge/1,remove/2,purge#/1,remove#/2} / {./2,=/2,if/3,nil/0,c_1/2,c_2/0,c_3/2,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {purge#,remove#} and constructors {.,=,if,nil} + Applied Processor: EmptyProcessor + Details: The problem is already closed. The intended complexity is O(1). ** Step 5.b:1: Failure MAYBE + Considered Problem: - Strict DPs: remove#(x,.(y,z)) -> c_3(remove#(x,z),remove#(x,z)) - Weak DPs: purge#(.(x,y)) -> purge#(remove(x,y)) purge#(.(x,y)) -> remove#(x,y) - Weak TRS: remove(x,.(y,z)) -> if(=(x,y),remove(x,z),.(y,remove(x,z))) remove(x,nil()) -> nil() - Signature: {purge/1,remove/2,purge#/1,remove#/2} / {./2,=/2,if/3,nil/0,c_1/2,c_2/0,c_3/2,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {purge#,remove#} and constructors {.,=,if,nil} + Applied Processor: EmptyProcessor + Details: The problem is still open. MAYBE