YES(O(1),O(1)) We are left with following problem, upon which TcT provides the certificate YES(O(1),O(1)). Strict Trs: { first(0(), X) -> nil() , first(s(X), cons(Y)) -> cons(Y) , from(X) -> cons(X) } Obligation: innermost runtime complexity Answer: YES(O(1),O(1)) We add the following innermost weak dependency pairs: Strict DPs: { first^#(0(), X) -> c_1() , first^#(s(X), cons(Y)) -> c_2() , from^#(X) -> c_3() } and mark the set of starting terms. We are left with following problem, upon which TcT provides the certificate YES(O(1),O(1)). Strict DPs: { first^#(0(), X) -> c_1() , first^#(s(X), cons(Y)) -> c_2() , from^#(X) -> c_3() } Strict Trs: { first(0(), X) -> nil() , first(s(X), cons(Y)) -> cons(Y) , from(X) -> cons(X) } Obligation: innermost runtime complexity Answer: YES(O(1),O(1)) No rule is usable, rules are removed from the input problem. We are left with following problem, upon which TcT provides the certificate YES(O(1),O(1)). Strict DPs: { first^#(0(), X) -> c_1() , first^#(s(X), cons(Y)) -> c_2() , from^#(X) -> c_3() } Obligation: innermost runtime complexity Answer: YES(O(1),O(1)) The weightgap principle applies (using the following constant growth matrix-interpretation) The following argument positions are usable: none TcT has computed the following constructor-restricted matrix interpretation. [0] = [2] [1] [s](x1) = [1] [1] [cons](x1) = [1] [2] [first^#](x1, x2) = [1 1] x1 + [1 1] x2 + [1] [1 1] [1 1] [1] [c_1] = [1] [0] [c_2] = [1] [1] [from^#](x1) = [2] [1] [c_3] = [1] [1] The following symbols are considered usable {first^#, from^#} The order satisfies the following ordering constraints: [first^#(0(), X)] = [1 1] X + [4] [1 1] [4] > [1] [0] = [c_1()] [first^#(s(X), cons(Y))] = [6] [6] > [1] [1] = [c_2()] [from^#(X)] = [2] [1] > [1] [1] = [c_3()] 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 YES(O(1),O(1)). Weak DPs: { first^#(0(), X) -> c_1() , first^#(s(X), cons(Y)) -> c_2() , from^#(X) -> c_3() } Obligation: innermost runtime complexity Answer: YES(O(1),O(1)) The following weak DPs constitute a sub-graph of the DG that is closed under successors. The DPs are removed. { first^#(0(), X) -> c_1() , first^#(s(X), cons(Y)) -> c_2() , from^#(X) -> c_3() } We are left with following problem, upon which TcT provides the certificate YES(O(1),O(1)). Rules: Empty Obligation: innermost runtime complexity Answer: YES(O(1),O(1)) Empty rules are trivially bounded Hurray, we answered YES(O(1),O(1))