MAYBE * Step 1: DependencyPairs MAYBE + Considered Problem: - Strict TRS: fib(0()) -> 0() fib(s(0())) -> s(0()) fib(s(s(x))) -> +(fib(s(x)),fib(x)) - Signature: {fib/1} / {+/2,0/0,s/1} - Obligation: innermost runtime complexity wrt. defined symbols {fib} and constructors {+,0,s} + Applied Processor: DependencyPairs {dpKind_ = DT} + Details: We add the following dependency tuples: Strict DPs fib#(0()) -> c_1() fib#(s(0())) -> c_2() fib#(s(s(x))) -> c_3(fib#(s(x)),fib#(x)) Weak DPs and mark the set of starting terms. * Step 2: UsableRules MAYBE + Considered Problem: - Strict DPs: fib#(0()) -> c_1() fib#(s(0())) -> c_2() fib#(s(s(x))) -> c_3(fib#(s(x)),fib#(x)) - Weak TRS: fib(0()) -> 0() fib(s(0())) -> s(0()) fib(s(s(x))) -> +(fib(s(x)),fib(x)) - Signature: {fib/1,fib#/1} / {+/2,0/0,s/1,c_1/0,c_2/0,c_3/2} - Obligation: innermost runtime complexity wrt. defined symbols {fib#} and constructors {+,0,s} + Applied Processor: UsableRules + Details: We replace rewrite rules by usable rules: fib#(0()) -> c_1() fib#(s(0())) -> c_2() fib#(s(s(x))) -> c_3(fib#(s(x)),fib#(x)) * Step 3: PredecessorEstimation MAYBE + Considered Problem: - Strict DPs: fib#(0()) -> c_1() fib#(s(0())) -> c_2() fib#(s(s(x))) -> c_3(fib#(s(x)),fib#(x)) - Signature: {fib/1,fib#/1} / {+/2,0/0,s/1,c_1/0,c_2/0,c_3/2} - Obligation: innermost runtime complexity wrt. defined symbols {fib#} and constructors {+,0,s} + Applied Processor: PredecessorEstimation {onSelection = all simple predecessor estimation selector} + Details: We estimate the number of application of {1,2} by application of Pre({1,2}) = {3}. Here rules are labelled as follows: 1: fib#(0()) -> c_1() 2: fib#(s(0())) -> c_2() 3: fib#(s(s(x))) -> c_3(fib#(s(x)),fib#(x)) * Step 4: RemoveWeakSuffixes MAYBE + Considered Problem: - Strict DPs: fib#(s(s(x))) -> c_3(fib#(s(x)),fib#(x)) - Weak DPs: fib#(0()) -> c_1() fib#(s(0())) -> c_2() - Signature: {fib/1,fib#/1} / {+/2,0/0,s/1,c_1/0,c_2/0,c_3/2} - Obligation: innermost runtime complexity wrt. defined symbols {fib#} and constructors {+,0,s} + Applied Processor: RemoveWeakSuffixes + Details: Consider the dependency graph 1:S:fib#(s(s(x))) -> c_3(fib#(s(x)),fib#(x)) -->_2 fib#(s(0())) -> c_2():3 -->_1 fib#(s(0())) -> c_2():3 -->_2 fib#(0()) -> c_1():2 -->_2 fib#(s(s(x))) -> c_3(fib#(s(x)),fib#(x)):1 -->_1 fib#(s(s(x))) -> c_3(fib#(s(x)),fib#(x)):1 2:W:fib#(0()) -> c_1() 3:W:fib#(s(0())) -> c_2() The following weak DPs constitute a sub-graph of the DG that is closed under successors. The DPs are removed. 2: fib#(0()) -> c_1() 3: fib#(s(0())) -> c_2() * Step 5: Failure MAYBE + Considered Problem: - Strict DPs: fib#(s(s(x))) -> c_3(fib#(s(x)),fib#(x)) - Signature: {fib/1,fib#/1} / {+/2,0/0,s/1,c_1/0,c_2/0,c_3/2} - Obligation: innermost runtime complexity wrt. defined symbols {fib#} and constructors {+,0,s} + Applied Processor: EmptyProcessor + Details: The problem is still open. MAYBE