MAYBE We are left with following problem, upon which TcT provides the certificate MAYBE. Strict Trs: { fib(0()) -> 0() , fib(s(0())) -> s(0()) , fib(s(s(x))) -> +(fib(s(x)), fib(x)) } Obligation: innermost runtime complexity Answer: MAYBE We add following weak dependency pairs: Strict DPs: { fib^#(0()) -> c_1() , fib^#(s(0())) -> c_2() , fib^#(s(s(x))) -> c_3(fib^#(s(x)), fib^#(x)) } and mark the set of starting terms. We are left with following problem, upon which TcT provides the certificate MAYBE. Strict DPs: { fib^#(0()) -> c_1() , fib^#(s(0())) -> c_2() , fib^#(s(s(x))) -> c_3(fib^#(s(x)), fib^#(x)) } Strict Trs: { fib(0()) -> 0() , fib(s(0())) -> s(0()) , fib(s(s(x))) -> +(fib(s(x)), fib(x)) } Obligation: innermost runtime complexity Answer: MAYBE No rule is usable, rules are removed from the input problem. We are left with following problem, upon which TcT provides the certificate MAYBE. Strict DPs: { fib^#(0()) -> c_1() , fib^#(s(0())) -> c_2() , fib^#(s(s(x))) -> c_3(fib^#(s(x)), fib^#(x)) } Obligation: innermost runtime complexity Answer: MAYBE The weightgap principle applies (using the following constant growth matrix-interpretation) The following argument positions are usable: Uargs(c_3) = {1, 2} TcT has computed following constructor-restricted matrix interpretation. [0] = [1] [s](x1) = [1] x1 + [1] [fib^#](x1) = [1] [c_1] = [0] [c_2] = [0] [c_3](x1, x2) = [1] x1 + [1] x2 + [1] This order satisfies following ordering constraints: Further, it can be verified that all rules not oriented are covered by the weightgap condition. We are left with following problem, upon which TcT provides the certificate MAYBE. Strict DPs: { fib^#(s(s(x))) -> c_3(fib^#(s(x)), fib^#(x)) } Weak DPs: { fib^#(0()) -> c_1() , fib^#(s(0())) -> c_2() } Obligation: innermost runtime complexity Answer: MAYBE The following weak DPs constitute a sub-graph of the DG that is closed under successors. The DPs are removed. { fib^#(0()) -> c_1() , fib^#(s(0())) -> c_2() } We are left with following problem, upon which TcT provides the certificate MAYBE. Strict DPs: { fib^#(s(s(x))) -> c_3(fib^#(s(x)), fib^#(x)) } Obligation: innermost runtime complexity Answer: MAYBE The input cannot be shown compatible Arrrr..