MAYBE We are left with following problem, upon which TcT provides the certificate MAYBE. Strict Trs: { active(terms(X)) -> terms(active(X)) , active(terms(N)) -> mark(cons(recip(sqr(N)), terms(s(N)))) , active(cons(X1, X2)) -> cons(active(X1), X2) , active(recip(X)) -> recip(active(X)) , active(sqr(X)) -> sqr(active(X)) , active(sqr(s(X))) -> mark(s(add(sqr(X), dbl(X)))) , active(sqr(0())) -> mark(0()) , active(add(X1, X2)) -> add(X1, active(X2)) , active(add(X1, X2)) -> add(active(X1), X2) , active(add(s(X), Y)) -> mark(s(add(X, Y))) , active(add(0(), X)) -> mark(X) , active(dbl(X)) -> dbl(active(X)) , active(dbl(s(X))) -> mark(s(s(dbl(X)))) , active(dbl(0())) -> mark(0()) , active(first(X1, X2)) -> first(X1, active(X2)) , active(first(X1, X2)) -> first(active(X1), X2) , active(first(s(X), cons(Y, Z))) -> mark(cons(Y, first(X, Z))) , active(first(0(), X)) -> mark(nil()) , terms(mark(X)) -> mark(terms(X)) , terms(ok(X)) -> ok(terms(X)) , cons(mark(X1), X2) -> mark(cons(X1, X2)) , cons(ok(X1), ok(X2)) -> ok(cons(X1, X2)) , recip(mark(X)) -> mark(recip(X)) , recip(ok(X)) -> ok(recip(X)) , sqr(mark(X)) -> mark(sqr(X)) , sqr(ok(X)) -> ok(sqr(X)) , s(ok(X)) -> ok(s(X)) , add(X1, mark(X2)) -> mark(add(X1, X2)) , add(mark(X1), X2) -> mark(add(X1, X2)) , add(ok(X1), ok(X2)) -> ok(add(X1, X2)) , dbl(mark(X)) -> mark(dbl(X)) , dbl(ok(X)) -> ok(dbl(X)) , first(X1, mark(X2)) -> mark(first(X1, X2)) , first(mark(X1), X2) -> mark(first(X1, X2)) , first(ok(X1), ok(X2)) -> ok(first(X1, X2)) , proper(terms(X)) -> terms(proper(X)) , proper(cons(X1, X2)) -> cons(proper(X1), proper(X2)) , proper(recip(X)) -> recip(proper(X)) , proper(sqr(X)) -> sqr(proper(X)) , proper(s(X)) -> s(proper(X)) , proper(0()) -> ok(0()) , proper(add(X1, X2)) -> add(proper(X1), proper(X2)) , proper(dbl(X)) -> dbl(proper(X)) , proper(first(X1, X2)) -> first(proper(X1), proper(X2)) , proper(nil()) -> ok(nil()) , top(mark(X)) -> top(proper(X)) , top(ok(X)) -> top(active(X)) } Obligation: innermost runtime complexity Answer: MAYBE None of the processors succeeded. Details of failed attempt(s): ----------------------------- 1) 'empty' failed due to the following reason: Empty strict component of the problem is NOT empty. 2) 'Best' failed due to the following reason: None of the processors succeeded. Details of failed attempt(s): ----------------------------- 1) 'WithProblem (timeout of 60 seconds)' failed due to the following reason: Computation stopped due to timeout after 60.0 seconds. 2) 'Best' failed due to the following reason: None of the processors succeeded. Details of failed attempt(s): ----------------------------- 1) 'WithProblem (timeout of 30 seconds) (timeout of 60 seconds)' failed due to the following reason: Computation stopped due to timeout after 30.0 seconds. 2) 'Best' failed due to the following reason: None of the processors succeeded. Details of failed attempt(s): ----------------------------- 1) 'bsearch-popstar (timeout of 60 seconds)' failed due to the following reason: The input cannot be shown compatible 2) 'Polynomial Path Order (PS) (timeout of 60 seconds)' failed due to the following reason: The input cannot be shown compatible 3) 'Fastest (timeout of 5 seconds) (timeout of 60 seconds)' failed due to the following reason: None of the processors succeeded. Details of failed attempt(s): ----------------------------- 1) 'Bounds with minimal-enrichment and initial automaton 'match'' failed due to the following reason: match-boundness of the problem could not be verified. 2) 'Bounds with perSymbol-enrichment and initial automaton 'match'' failed due to the following reason: match-boundness of the problem could not be verified. Arrrr..