We are left with following problem, upon which TcT provides the certificate YES(O(1),O(1)). Strict Trs: { terms(N) -> cons(recip(sqr(N))) , sqr(0()) -> 0() , sqr(s()) -> s() , dbl(0()) -> 0() , dbl(s()) -> s() , add(0(), X) -> X , add(s(), Y) -> s() , first(0(), X) -> nil() , first(s(), cons(Y)) -> cons(Y) } Obligation: innermost runtime complexity Answer: YES(O(1),O(1)) We add the following weak dependency pairs: Strict DPs: { terms^#(N) -> c_1(sqr^#(N)) , sqr^#(0()) -> c_2() , sqr^#(s()) -> c_3() , dbl^#(0()) -> c_4() , dbl^#(s()) -> c_5() , add^#(0(), X) -> c_6() , add^#(s(), Y) -> c_7() , first^#(0(), X) -> c_8() , first^#(s(), cons(Y)) -> c_9() } 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: { terms^#(N) -> c_1(sqr^#(N)) , sqr^#(0()) -> c_2() , sqr^#(s()) -> c_3() , dbl^#(0()) -> c_4() , dbl^#(s()) -> c_5() , add^#(0(), X) -> c_6() , add^#(s(), Y) -> c_7() , first^#(0(), X) -> c_8() , first^#(s(), cons(Y)) -> c_9() } Strict Trs: { terms(N) -> cons(recip(sqr(N))) , sqr(0()) -> 0() , sqr(s()) -> s() , dbl(0()) -> 0() , dbl(s()) -> s() , add(0(), X) -> X , add(s(), Y) -> s() , first(0(), X) -> nil() , first(s(), cons(Y)) -> cons(Y) } 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: { terms^#(N) -> c_1(sqr^#(N)) , sqr^#(0()) -> c_2() , sqr^#(s()) -> c_3() , dbl^#(0()) -> c_4() , dbl^#(s()) -> c_5() , add^#(0(), X) -> c_6() , add^#(s(), Y) -> c_7() , first^#(0(), X) -> c_8() , first^#(s(), cons(Y)) -> c_9() } 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: Uargs(c_1) = {1} TcT has computed the following constructor-restricted matrix interpretation. [cons](x1) = [0] [0] [0] = [0] [0] [s] = [1] [1] [terms^#](x1) = [1 2] x1 + [2] [2 1] [2] [c_1](x1) = [1 0] x1 + [0] [0 1] [0] [sqr^#](x1) = [0] [0] [c_2] = [0] [0] [c_3] = [0] [0] [dbl^#](x1) = [0] [0] [c_4] = [0] [0] [c_5] = [0] [0] [add^#](x1, x2) = [0] [0] [c_6] = [0] [0] [c_7] = [0] [0] [first^#](x1, x2) = [1 0] x1 + [0] [0 0] [0] [c_8] = [0] [0] [c_9] = [0] [0] The order satisfies the following ordering constraints: [terms^#(N)] = [1 2] N + [2] [2 1] [2] > [0] [0] = [c_1(sqr^#(N))] [sqr^#(0())] = [0] [0] >= [0] [0] = [c_2()] [sqr^#(s())] = [0] [0] >= [0] [0] = [c_3()] [dbl^#(0())] = [0] [0] >= [0] [0] = [c_4()] [dbl^#(s())] = [0] [0] >= [0] [0] = [c_5()] [add^#(0(), X)] = [0] [0] >= [0] [0] = [c_6()] [add^#(s(), Y)] = [0] [0] >= [0] [0] = [c_7()] [first^#(0(), X)] = [0] [0] >= [0] [0] = [c_8()] [first^#(s(), cons(Y))] = [1] [0] > [0] [0] = [c_9()] 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)). Strict DPs: { sqr^#(0()) -> c_2() , sqr^#(s()) -> c_3() , dbl^#(0()) -> c_4() , dbl^#(s()) -> c_5() , add^#(0(), X) -> c_6() , add^#(s(), Y) -> c_7() , first^#(0(), X) -> c_8() } Weak DPs: { terms^#(N) -> c_1(sqr^#(N)) , first^#(s(), cons(Y)) -> c_9() } Obligation: innermost runtime complexity Answer: YES(O(1),O(1)) We estimate the number of application of {3,4,5,6,7} by applications of Pre({3,4,5,6,7}) = {}. Here rules are labeled as follows: DPs: { 1: sqr^#(0()) -> c_2() , 2: sqr^#(s()) -> c_3() , 3: dbl^#(0()) -> c_4() , 4: dbl^#(s()) -> c_5() , 5: add^#(0(), X) -> c_6() , 6: add^#(s(), Y) -> c_7() , 7: first^#(0(), X) -> c_8() , 8: terms^#(N) -> c_1(sqr^#(N)) , 9: first^#(s(), cons(Y)) -> c_9() } We are left with following problem, upon which TcT provides the certificate YES(O(1),O(1)). Strict DPs: { sqr^#(0()) -> c_2() , sqr^#(s()) -> c_3() } Weak DPs: { terms^#(N) -> c_1(sqr^#(N)) , dbl^#(0()) -> c_4() , dbl^#(s()) -> c_5() , add^#(0(), X) -> c_6() , add^#(s(), Y) -> c_7() , first^#(0(), X) -> c_8() , first^#(s(), cons(Y)) -> c_9() } 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. { dbl^#(0()) -> c_4() , dbl^#(s()) -> c_5() , add^#(0(), X) -> c_6() , add^#(s(), Y) -> c_7() , first^#(0(), X) -> c_8() , first^#(s(), cons(Y)) -> c_9() } We are left with following problem, upon which TcT provides the certificate YES(O(1),O(1)). Strict DPs: { sqr^#(0()) -> c_2() , sqr^#(s()) -> c_3() } Weak DPs: { terms^#(N) -> c_1(sqr^#(N)) } Obligation: innermost runtime complexity Answer: YES(O(1),O(1)) Consider the dependency graph 1: sqr^#(0()) -> c_2() 2: sqr^#(s()) -> c_3() 3: terms^#(N) -> c_1(sqr^#(N)) -->_1 sqr^#(s()) -> c_3() :2 -->_1 sqr^#(0()) -> c_2() :1 Following roots of the dependency graph are removed, as the considered set of starting terms is closed under reduction with respect to these rules (modulo compound contexts). { terms^#(N) -> c_1(sqr^#(N)) } We are left with following problem, upon which TcT provides the certificate YES(O(1),O(1)). Strict DPs: { sqr^#(0()) -> c_2() , sqr^#(s()) -> c_3() } Obligation: innermost runtime complexity Answer: YES(O(1),O(1)) Consider the dependency graph 1: sqr^#(0()) -> c_2() 2: sqr^#(s()) -> c_3() Following roots of the dependency graph are removed, as the considered set of starting terms is closed under reduction with respect to these rules (modulo compound contexts). { sqr^#(0()) -> c_2() , sqr^#(s()) -> 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))