MAYBE We are left with following problem, upon which TcT provides the certificate MAYBE. Strict Trs: { active(primes()) -> mark(sieve(from(s(s(0()))))) , active(sieve(X)) -> sieve(active(X)) , active(sieve(cons(X, Y))) -> mark(cons(X, filter(X, sieve(Y)))) , active(from(X)) -> mark(cons(X, from(s(X)))) , active(from(X)) -> from(active(X)) , active(s(X)) -> s(active(X)) , active(cons(X1, X2)) -> cons(active(X1), X2) , active(head(X)) -> head(active(X)) , active(head(cons(X, Y))) -> mark(X) , active(tail(X)) -> tail(active(X)) , active(tail(cons(X, Y))) -> mark(Y) , active(if(X1, X2, X3)) -> if(active(X1), X2, X3) , active(if(true(), X, Y)) -> mark(X) , active(if(false(), X, Y)) -> mark(Y) , active(filter(X1, X2)) -> filter(X1, active(X2)) , active(filter(X1, X2)) -> filter(active(X1), X2) , active(filter(s(s(X)), cons(Y, Z))) -> mark(if(divides(s(s(X)), Y), filter(s(s(X)), Z), cons(Y, filter(X, sieve(Y))))) , active(divides(X1, X2)) -> divides(X1, active(X2)) , active(divides(X1, X2)) -> divides(active(X1), X2) , sieve(mark(X)) -> mark(sieve(X)) , sieve(ok(X)) -> ok(sieve(X)) , from(mark(X)) -> mark(from(X)) , from(ok(X)) -> ok(from(X)) , s(mark(X)) -> mark(s(X)) , s(ok(X)) -> ok(s(X)) , cons(mark(X1), X2) -> mark(cons(X1, X2)) , cons(ok(X1), ok(X2)) -> ok(cons(X1, X2)) , head(mark(X)) -> mark(head(X)) , head(ok(X)) -> ok(head(X)) , tail(mark(X)) -> mark(tail(X)) , tail(ok(X)) -> ok(tail(X)) , if(mark(X1), X2, X3) -> mark(if(X1, X2, X3)) , if(ok(X1), ok(X2), ok(X3)) -> ok(if(X1, X2, X3)) , filter(X1, mark(X2)) -> mark(filter(X1, X2)) , filter(mark(X1), X2) -> mark(filter(X1, X2)) , filter(ok(X1), ok(X2)) -> ok(filter(X1, X2)) , divides(X1, mark(X2)) -> mark(divides(X1, X2)) , divides(mark(X1), X2) -> mark(divides(X1, X2)) , divides(ok(X1), ok(X2)) -> ok(divides(X1, X2)) , proper(primes()) -> ok(primes()) , proper(sieve(X)) -> sieve(proper(X)) , proper(from(X)) -> from(proper(X)) , proper(s(X)) -> s(proper(X)) , proper(0()) -> ok(0()) , proper(cons(X1, X2)) -> cons(proper(X1), proper(X2)) , proper(head(X)) -> head(proper(X)) , proper(tail(X)) -> tail(proper(X)) , proper(if(X1, X2, X3)) -> if(proper(X1), proper(X2), proper(X3)) , proper(true()) -> ok(true()) , proper(false()) -> ok(false()) , proper(filter(X1, X2)) -> filter(proper(X1), proper(X2)) , proper(divides(X1, X2)) -> divides(proper(X1), proper(X2)) , 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..