MAYBE * Step 1: InnermostRuleRemoval MAYBE + Considered Problem: - Strict TRS: f(x,x) -> f(i(x),g(g(x))) f(x,y) -> x f(x,i(x)) -> f(x,x) f(i(x),i(g(x))) -> a() g(x) -> i(x) - Signature: {f/2,g/1} / {a/0,i/1} - Obligation: innermost runtime complexity wrt. defined symbols {f,g} and constructors {a,i} + Applied Processor: InnermostRuleRemoval + Details: Arguments of following rules are not normal-forms. f(i(x),i(g(x))) -> a() All above mentioned rules can be savely removed. * Step 2: DependencyPairs MAYBE + Considered Problem: - Strict TRS: f(x,x) -> f(i(x),g(g(x))) f(x,y) -> x f(x,i(x)) -> f(x,x) g(x) -> i(x) - Signature: {f/2,g/1} / {a/0,i/1} - Obligation: innermost runtime complexity wrt. defined symbols {f,g} and constructors {a,i} + Applied Processor: DependencyPairs {dpKind_ = WIDP} + Details: We add the following weak innermost dependency pairs: Strict DPs f#(x,x) -> c_1(f#(i(x),g(g(x)))) f#(x,y) -> c_2() f#(x,i(x)) -> c_3(f#(x,x)) g#(x) -> c_4() Weak DPs and mark the set of starting terms. * Step 3: UsableRules MAYBE + Considered Problem: - Strict DPs: f#(x,x) -> c_1(f#(i(x),g(g(x)))) f#(x,y) -> c_2() f#(x,i(x)) -> c_3(f#(x,x)) g#(x) -> c_4() - Strict TRS: f(x,x) -> f(i(x),g(g(x))) f(x,y) -> x f(x,i(x)) -> f(x,x) g(x) -> i(x) - Signature: {f/2,g/1,f#/2,g#/1} / {a/0,i/1,c_1/1,c_2/0,c_3/1,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {f#,g#} and constructors {a,i} + Applied Processor: UsableRules + Details: We replace rewrite rules by usable rules: g(x) -> i(x) f#(x,x) -> c_1(f#(i(x),g(g(x)))) f#(x,y) -> c_2() f#(x,i(x)) -> c_3(f#(x,x)) g#(x) -> c_4() * Step 4: WeightGap MAYBE + Considered Problem: - Strict DPs: f#(x,x) -> c_1(f#(i(x),g(g(x)))) f#(x,y) -> c_2() f#(x,i(x)) -> c_3(f#(x,x)) g#(x) -> c_4() - Strict TRS: g(x) -> i(x) - Signature: {f/2,g/1,f#/2,g#/1} / {a/0,i/1,c_1/1,c_2/0,c_3/1,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {f#,g#} and constructors {a,i} + Applied Processor: WeightGap {wgDimension = 1, wgDegree = 1, wgKind = Algebraic, wgUArgs = UArgs, wgOn = WgOnTrs} + 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(g) = {1}, uargs(f#) = {2}, uargs(c_1) = {1}, uargs(c_3) = {1} Following symbols are considered usable: all TcT has computed the following interpretation: p(a) = [0] p(f) = [0] p(g) = [1] x1 + [1] p(i) = [1] x1 + [0] p(f#) = [1] x2 + [10] p(g#) = [0] p(c_1) = [1] x1 + [0] p(c_2) = [0] p(c_3) = [1] x1 + [0] p(c_4) = [0] Following rules are strictly oriented: f#(x,y) = [1] y + [10] > [0] = c_2() g(x) = [1] x + [1] > [1] x + [0] = i(x) Following rules are (at-least) weakly oriented: f#(x,x) = [1] x + [10] >= [1] x + [12] = c_1(f#(i(x),g(g(x)))) f#(x,i(x)) = [1] x + [10] >= [1] x + [10] = c_3(f#(x,x)) g#(x) = [0] >= [0] = c_4() Further, it can be verified that all rules not oriented are covered by the weightgap condition. * Step 5: PredecessorEstimation MAYBE + Considered Problem: - Strict DPs: f#(x,x) -> c_1(f#(i(x),g(g(x)))) f#(x,i(x)) -> c_3(f#(x,x)) g#(x) -> c_4() - Weak DPs: f#(x,y) -> c_2() - Weak TRS: g(x) -> i(x) - Signature: {f/2,g/1,f#/2,g#/1} / {a/0,i/1,c_1/1,c_2/0,c_3/1,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {f#,g#} and constructors {a,i} + Applied Processor: PredecessorEstimation {onSelection = all simple predecessor estimation selector} + Details: We estimate the number of application of {3} by application of Pre({3}) = {}. Here rules are labelled as follows: 1: f#(x,x) -> c_1(f#(i(x),g(g(x)))) 2: f#(x,i(x)) -> c_3(f#(x,x)) 3: g#(x) -> c_4() 4: f#(x,y) -> c_2() * Step 6: RemoveWeakSuffixes MAYBE + Considered Problem: - Strict DPs: f#(x,x) -> c_1(f#(i(x),g(g(x)))) f#(x,i(x)) -> c_3(f#(x,x)) - Weak DPs: f#(x,y) -> c_2() g#(x) -> c_4() - Weak TRS: g(x) -> i(x) - Signature: {f/2,g/1,f#/2,g#/1} / {a/0,i/1,c_1/1,c_2/0,c_3/1,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {f#,g#} and constructors {a,i} + Applied Processor: RemoveWeakSuffixes + Details: Consider the dependency graph 1:S:f#(x,x) -> c_1(f#(i(x),g(g(x)))) -->_1 f#(x,i(x)) -> c_3(f#(x,x)):2 -->_1 f#(x,y) -> c_2():3 -->_1 f#(x,x) -> c_1(f#(i(x),g(g(x)))):1 2:S:f#(x,i(x)) -> c_3(f#(x,x)) -->_1 f#(x,y) -> c_2():3 -->_1 f#(x,x) -> c_1(f#(i(x),g(g(x)))):1 3:W:f#(x,y) -> c_2() 4:W:g#(x) -> c_4() The following weak DPs constitute a sub-graph of the DG that is closed under successors. The DPs are removed. 4: g#(x) -> c_4() 3: f#(x,y) -> c_2() * Step 7: Failure MAYBE + Considered Problem: - Strict DPs: f#(x,x) -> c_1(f#(i(x),g(g(x)))) f#(x,i(x)) -> c_3(f#(x,x)) - Weak TRS: g(x) -> i(x) - Signature: {f/2,g/1,f#/2,g#/1} / {a/0,i/1,c_1/1,c_2/0,c_3/1,c_4/0} - Obligation: innermost runtime complexity wrt. defined symbols {f#,g#} and constructors {a,i} + Applied Processor: EmptyProcessor + Details: The problem is still open. MAYBE