MAYBE We are left with following problem, upon which TcT provides the certificate MAYBE. Strict Trs: { append(@l1, @l2) -> append#1(@l1, @l2) , append#1(::(@x, @xs), @l2) -> ::(@x, append(@xs, @l2)) , append#1(nil(), @l2) -> @l2 , append3(@l1, @l2) -> append3#1(@l1, @l2) , append3#1(::(@x, @xs), @l2) -> ::(@x, append3(@xs, @l2)) , append3#1(nil(), @l2) -> @l2 , append4(@l1, @l2) -> append4#1(@l1, @l2) , append4#1(::(@x, @xs), @l2) -> ::(@x, append4(@xs, @l2)) , append4#1(nil(), @l2) -> @l2 , attach(@n, @l) -> attach#1(@l, @n) , attach#1(::(@x, @xs), @n) -> ::(tuple#2(@n, @x), attach(@n, @xs)) , attach#1(nil(), @n) -> nil() , attach3(@n, @l) -> attach3#1(@l, @n) , attach3#1(::(@x, @xs), @n) -> ::(tuple#2(@n, @x), attach3(@n, @xs)) , attach3#1(nil(), @n) -> nil() , attach4(@n, @l) -> attach4#1(@l, @n) , attach4#1(::(@x, @xs), @n) -> ::(tuple#2(@n, @x), attach4(@n, @xs)) , attach4#1(nil(), @n) -> nil() , pairs(@l) -> pairs#1(@l) , pairs#1(::(@x, @xs)) -> append(attach(@x, @xs), pairs(@xs)) , pairs#1(nil()) -> nil() , pairs'(@l) -> pairs'#1(@l) , pairs'#1(::(@x, @xs)) -> append(pairs'(@xs), attach(@x, @xs)) , pairs'#1(nil()) -> nil() , pairs_aux(@l, @acc) -> pairs_aux#1(@l, @acc) , pairs_aux#1(::(@x, @xs), @acc) -> pairs_aux(@xs, append(attach(@x, @xs), @acc)) , pairs_aux#1(nil(), @acc) -> @acc , quadruples(@l) -> quadruples#1(@l) , quadruples#1(::(@x, @xs)) -> append4(attach4(@x, triples(@xs)), quadruples(@xs)) , quadruples#1(nil()) -> nil() , triples(@l) -> triples#1(@l) , triples#1(::(@x, @xs)) -> append3(attach3(@x, pairs(@xs)), triples(@xs)) , triples#1(nil()) -> nil() } Obligation: innermost runtime complexity Answer: MAYBE None of the processors succeeded. Details of failed attempt(s): ----------------------------- 1) 'Fastest' failed due to the following reason: None of the processors succeeded. Details of failed attempt(s): ----------------------------- 1) 'matrix interpretation of dimension 4' failed due to the following reason: The input cannot be shown compatible 2) 'matrix interpretation of dimension 3' failed due to the following reason: The input cannot be shown compatible 3) 'matrix interpretation of dimension 3' failed due to the following reason: The input cannot be shown compatible 4) 'matrix interpretation of dimension 2' failed due to the following reason: The input cannot be shown compatible 5) 'matrix interpretation of dimension 2' failed due to the following reason: The input cannot be shown compatible 6) 'matrix interpretation of dimension 1' failed due to the following reason: The input cannot be shown compatible 2) 'Fastest' failed due to the following reason: None of the processors succeeded. Details of failed attempt(s): ----------------------------- 1) 'custom shape polynomial interpretation' failed due to the following reason: Following exception was raised: stack overflow 2) 'custom shape polynomial interpretation' failed due to the following reason: Following exception was raised: stack overflow 3) 'linear polynomial interpretation' failed due to the following reason: The input cannot be shown compatible Arrrr..