MAYBE We are left with following problem, upon which TcT provides the certificate MAYBE. Strict Trs: { fstsplit(0(), x) -> nil() , fstsplit(s(n), nil()) -> nil() , fstsplit(s(n), cons(h, t)) -> cons(h, fstsplit(n, t)) , sndsplit(0(), x) -> x , sndsplit(s(n), nil()) -> nil() , sndsplit(s(n), cons(h, t)) -> sndsplit(n, t) , empty(nil()) -> true() , empty(cons(h, t)) -> false() , leq(0(), m) -> true() , leq(s(n), 0()) -> false() , leq(s(n), s(m)) -> leq(n, m) , length(nil()) -> 0() , length(cons(h, t)) -> s(length(t)) , app(nil(), x) -> x , app(cons(h, t), x) -> cons(h, app(t, x)) , map_f(pid, nil()) -> nil() , map_f(pid, cons(h, t)) -> app(f(pid, h), map_f(pid, t)) , head(cons(h, t)) -> h , tail(cons(h, t)) -> t , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_1(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_1))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_2(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_2))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_5(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(two(), head(in_2)))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_6(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_3))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_9(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(three(), head(in_3)))) , if_1(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(sndsplit(m, st_1), cons(fstsplit(m, st_1), in_2), st_2, in_3, st_3, m) , if_2(st_1, in_2, st_2, in_3, st_3, m, true()) -> if_3(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_2))) , if_2(st_1, in_2, st_2, in_3, st_3, m, false()) -> if_4(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(two(), head(in_2)), st_2)))) , if_3(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, in_2, sndsplit(m, st_2), cons(fstsplit(m, st_2), in_3), st_3, m) , if_4(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, tail(in_2), sndsplit(m, app(map_f(two(), head(in_2)), st_2)), cons(fstsplit(m, app(map_f(two(), head(in_2)), st_2)), in_3), st_3, m) , if_5(st_1, in_2, st_2, in_3, st_3, m, true()) -> ring(st_1, tail(in_2), st_2, in_3, st_3, m) , if_6(st_1, in_2, st_2, in_3, st_3, m, true()) -> if_7(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_3))) , if_6(st_1, in_2, st_2, in_3, st_3, m, false()) -> if_8(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(three(), head(in_3)), st_3)))) , if_7(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, in_2, st_2, in_3, sndsplit(m, st_3), m) , if_8(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, in_2, st_2, tail(in_3), sndsplit(m, app(map_f(three(), head(in_3)), st_3)), m) , if_9(st_1, in_2, st_2, in_3, st_3, m, true()) -> ring(st_1, in_2, st_2, tail(in_3), st_3, m) } Obligation: innermost runtime complexity Answer: MAYBE We add following dependency tuples: Strict DPs: { fstsplit^#(0(), x) -> c_1() , fstsplit^#(s(n), nil()) -> c_2() , fstsplit^#(s(n), cons(h, t)) -> c_3(fstsplit^#(n, t)) , sndsplit^#(0(), x) -> c_4() , sndsplit^#(s(n), nil()) -> c_5() , sndsplit^#(s(n), cons(h, t)) -> c_6(sndsplit^#(n, t)) , empty^#(nil()) -> c_7() , empty^#(cons(h, t)) -> c_8() , leq^#(0(), m) -> c_9() , leq^#(s(n), 0()) -> c_10() , leq^#(s(n), s(m)) -> c_11(leq^#(n, m)) , length^#(nil()) -> c_12() , length^#(cons(h, t)) -> c_13(length^#(t)) , app^#(nil(), x) -> c_14() , app^#(cons(h, t), x) -> c_15(app^#(t, x)) , map_f^#(pid, nil()) -> c_16() , map_f^#(pid, cons(h, t)) -> c_17(app^#(f(pid, h), map_f(pid, t)), map_f^#(pid, t)) , head^#(cons(h, t)) -> c_18() , tail^#(cons(h, t)) -> c_19() , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_20(if_1^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_1))), empty^#(fstsplit(m, st_1)), fstsplit^#(m, st_1)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_21(if_2^#(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_2))), leq^#(m, length(st_2)), length^#(st_2)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_22(if_5^#(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(two(), head(in_2)))), empty^#(map_f(two(), head(in_2))), map_f^#(two(), head(in_2)), head^#(in_2)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_23(if_6^#(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_3))), leq^#(m, length(st_3)), length^#(st_3)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_24(if_9^#(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(three(), head(in_3)))), empty^#(map_f(three(), head(in_3))), map_f^#(three(), head(in_3)), head^#(in_3)) , if_1^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_25(ring^#(sndsplit(m, st_1), cons(fstsplit(m, st_1), in_2), st_2, in_3, st_3, m), sndsplit^#(m, st_1), fstsplit^#(m, st_1)) , if_2^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_26(if_3^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_2))), empty^#(fstsplit(m, st_2)), fstsplit^#(m, st_2)) , if_2^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_27(if_4^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(two(), head(in_2)), st_2)))), empty^#(fstsplit(m, app(map_f(two(), head(in_2)), st_2))), fstsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), head^#(in_2)) , if_5^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_30(ring^#(st_1, tail(in_2), st_2, in_3, st_3, m), tail^#(in_2)) , if_6^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_31(if_7^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_3))), empty^#(fstsplit(m, st_3)), fstsplit^#(m, st_3)) , if_6^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_32(if_8^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(three(), head(in_3)), st_3)))), empty^#(fstsplit(m, app(map_f(three(), head(in_3)), st_3))), fstsplit^#(m, app(map_f(three(), head(in_3)), st_3)), app^#(map_f(three(), head(in_3)), st_3), map_f^#(three(), head(in_3)), head^#(in_3)) , if_9^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_35(ring^#(st_1, in_2, st_2, tail(in_3), st_3, m), tail^#(in_3)) , if_3^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_28(ring^#(st_1, in_2, sndsplit(m, st_2), cons(fstsplit(m, st_2), in_3), st_3, m), sndsplit^#(m, st_2), fstsplit^#(m, st_2)) , if_4^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_29(ring^#(st_1, tail(in_2), sndsplit(m, app(map_f(two(), head(in_2)), st_2)), cons(fstsplit(m, app(map_f(two(), head(in_2)), st_2)), in_3), st_3, m), tail^#(in_2), sndsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), head^#(in_2), fstsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), head^#(in_2)) , if_7^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_33(ring^#(st_1, in_2, st_2, in_3, sndsplit(m, st_3), m), sndsplit^#(m, st_3)) , if_8^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_34(ring^#(st_1, in_2, st_2, tail(in_3), sndsplit(m, app(map_f(three(), head(in_3)), st_3)), m), tail^#(in_3), sndsplit^#(m, app(map_f(three(), head(in_3)), st_3)), app^#(map_f(three(), head(in_3)), st_3), map_f^#(three(), head(in_3)), head^#(in_3)) } and mark the set of starting terms. We are left with following problem, upon which TcT provides the certificate MAYBE. Strict DPs: { fstsplit^#(0(), x) -> c_1() , fstsplit^#(s(n), nil()) -> c_2() , fstsplit^#(s(n), cons(h, t)) -> c_3(fstsplit^#(n, t)) , sndsplit^#(0(), x) -> c_4() , sndsplit^#(s(n), nil()) -> c_5() , sndsplit^#(s(n), cons(h, t)) -> c_6(sndsplit^#(n, t)) , empty^#(nil()) -> c_7() , empty^#(cons(h, t)) -> c_8() , leq^#(0(), m) -> c_9() , leq^#(s(n), 0()) -> c_10() , leq^#(s(n), s(m)) -> c_11(leq^#(n, m)) , length^#(nil()) -> c_12() , length^#(cons(h, t)) -> c_13(length^#(t)) , app^#(nil(), x) -> c_14() , app^#(cons(h, t), x) -> c_15(app^#(t, x)) , map_f^#(pid, nil()) -> c_16() , map_f^#(pid, cons(h, t)) -> c_17(app^#(f(pid, h), map_f(pid, t)), map_f^#(pid, t)) , head^#(cons(h, t)) -> c_18() , tail^#(cons(h, t)) -> c_19() , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_20(if_1^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_1))), empty^#(fstsplit(m, st_1)), fstsplit^#(m, st_1)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_21(if_2^#(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_2))), leq^#(m, length(st_2)), length^#(st_2)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_22(if_5^#(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(two(), head(in_2)))), empty^#(map_f(two(), head(in_2))), map_f^#(two(), head(in_2)), head^#(in_2)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_23(if_6^#(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_3))), leq^#(m, length(st_3)), length^#(st_3)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_24(if_9^#(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(three(), head(in_3)))), empty^#(map_f(three(), head(in_3))), map_f^#(three(), head(in_3)), head^#(in_3)) , if_1^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_25(ring^#(sndsplit(m, st_1), cons(fstsplit(m, st_1), in_2), st_2, in_3, st_3, m), sndsplit^#(m, st_1), fstsplit^#(m, st_1)) , if_2^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_26(if_3^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_2))), empty^#(fstsplit(m, st_2)), fstsplit^#(m, st_2)) , if_2^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_27(if_4^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(two(), head(in_2)), st_2)))), empty^#(fstsplit(m, app(map_f(two(), head(in_2)), st_2))), fstsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), head^#(in_2)) , if_5^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_30(ring^#(st_1, tail(in_2), st_2, in_3, st_3, m), tail^#(in_2)) , if_6^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_31(if_7^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_3))), empty^#(fstsplit(m, st_3)), fstsplit^#(m, st_3)) , if_6^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_32(if_8^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(three(), head(in_3)), st_3)))), empty^#(fstsplit(m, app(map_f(three(), head(in_3)), st_3))), fstsplit^#(m, app(map_f(three(), head(in_3)), st_3)), app^#(map_f(three(), head(in_3)), st_3), map_f^#(three(), head(in_3)), head^#(in_3)) , if_9^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_35(ring^#(st_1, in_2, st_2, tail(in_3), st_3, m), tail^#(in_3)) , if_3^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_28(ring^#(st_1, in_2, sndsplit(m, st_2), cons(fstsplit(m, st_2), in_3), st_3, m), sndsplit^#(m, st_2), fstsplit^#(m, st_2)) , if_4^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_29(ring^#(st_1, tail(in_2), sndsplit(m, app(map_f(two(), head(in_2)), st_2)), cons(fstsplit(m, app(map_f(two(), head(in_2)), st_2)), in_3), st_3, m), tail^#(in_2), sndsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), head^#(in_2), fstsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), head^#(in_2)) , if_7^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_33(ring^#(st_1, in_2, st_2, in_3, sndsplit(m, st_3), m), sndsplit^#(m, st_3)) , if_8^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_34(ring^#(st_1, in_2, st_2, tail(in_3), sndsplit(m, app(map_f(three(), head(in_3)), st_3)), m), tail^#(in_3), sndsplit^#(m, app(map_f(three(), head(in_3)), st_3)), app^#(map_f(three(), head(in_3)), st_3), map_f^#(three(), head(in_3)), head^#(in_3)) } Weak Trs: { fstsplit(0(), x) -> nil() , fstsplit(s(n), nil()) -> nil() , fstsplit(s(n), cons(h, t)) -> cons(h, fstsplit(n, t)) , sndsplit(0(), x) -> x , sndsplit(s(n), nil()) -> nil() , sndsplit(s(n), cons(h, t)) -> sndsplit(n, t) , empty(nil()) -> true() , empty(cons(h, t)) -> false() , leq(0(), m) -> true() , leq(s(n), 0()) -> false() , leq(s(n), s(m)) -> leq(n, m) , length(nil()) -> 0() , length(cons(h, t)) -> s(length(t)) , app(nil(), x) -> x , app(cons(h, t), x) -> cons(h, app(t, x)) , map_f(pid, nil()) -> nil() , map_f(pid, cons(h, t)) -> app(f(pid, h), map_f(pid, t)) , head(cons(h, t)) -> h , tail(cons(h, t)) -> t , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_1(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_1))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_2(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_2))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_5(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(two(), head(in_2)))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_6(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_3))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_9(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(three(), head(in_3)))) , if_1(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(sndsplit(m, st_1), cons(fstsplit(m, st_1), in_2), st_2, in_3, st_3, m) , if_2(st_1, in_2, st_2, in_3, st_3, m, true()) -> if_3(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_2))) , if_2(st_1, in_2, st_2, in_3, st_3, m, false()) -> if_4(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(two(), head(in_2)), st_2)))) , if_3(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, in_2, sndsplit(m, st_2), cons(fstsplit(m, st_2), in_3), st_3, m) , if_4(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, tail(in_2), sndsplit(m, app(map_f(two(), head(in_2)), st_2)), cons(fstsplit(m, app(map_f(two(), head(in_2)), st_2)), in_3), st_3, m) , if_5(st_1, in_2, st_2, in_3, st_3, m, true()) -> ring(st_1, tail(in_2), st_2, in_3, st_3, m) , if_6(st_1, in_2, st_2, in_3, st_3, m, true()) -> if_7(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_3))) , if_6(st_1, in_2, st_2, in_3, st_3, m, false()) -> if_8(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(three(), head(in_3)), st_3)))) , if_7(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, in_2, st_2, in_3, sndsplit(m, st_3), m) , if_8(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, in_2, st_2, tail(in_3), sndsplit(m, app(map_f(three(), head(in_3)), st_3)), m) , if_9(st_1, in_2, st_2, in_3, st_3, m, true()) -> ring(st_1, in_2, st_2, tail(in_3), st_3, m) } Obligation: innermost runtime complexity Answer: MAYBE We estimate the number of application of {1,2,4,5,7,8,9,10,12,14,16,18,19} by applications of Pre({1,2,4,5,7,8,9,10,12,14,16,18,19}) = {3,6,11,13,15,17,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35}. Here rules are labeled as follows: DPs: { 1: fstsplit^#(0(), x) -> c_1() , 2: fstsplit^#(s(n), nil()) -> c_2() , 3: fstsplit^#(s(n), cons(h, t)) -> c_3(fstsplit^#(n, t)) , 4: sndsplit^#(0(), x) -> c_4() , 5: sndsplit^#(s(n), nil()) -> c_5() , 6: sndsplit^#(s(n), cons(h, t)) -> c_6(sndsplit^#(n, t)) , 7: empty^#(nil()) -> c_7() , 8: empty^#(cons(h, t)) -> c_8() , 9: leq^#(0(), m) -> c_9() , 10: leq^#(s(n), 0()) -> c_10() , 11: leq^#(s(n), s(m)) -> c_11(leq^#(n, m)) , 12: length^#(nil()) -> c_12() , 13: length^#(cons(h, t)) -> c_13(length^#(t)) , 14: app^#(nil(), x) -> c_14() , 15: app^#(cons(h, t), x) -> c_15(app^#(t, x)) , 16: map_f^#(pid, nil()) -> c_16() , 17: map_f^#(pid, cons(h, t)) -> c_17(app^#(f(pid, h), map_f(pid, t)), map_f^#(pid, t)) , 18: head^#(cons(h, t)) -> c_18() , 19: tail^#(cons(h, t)) -> c_19() , 20: ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_20(if_1^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_1))), empty^#(fstsplit(m, st_1)), fstsplit^#(m, st_1)) , 21: ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_21(if_2^#(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_2))), leq^#(m, length(st_2)), length^#(st_2)) , 22: ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_22(if_5^#(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(two(), head(in_2)))), empty^#(map_f(two(), head(in_2))), map_f^#(two(), head(in_2)), head^#(in_2)) , 23: ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_23(if_6^#(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_3))), leq^#(m, length(st_3)), length^#(st_3)) , 24: ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_24(if_9^#(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(three(), head(in_3)))), empty^#(map_f(three(), head(in_3))), map_f^#(three(), head(in_3)), head^#(in_3)) , 25: if_1^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_25(ring^#(sndsplit(m, st_1), cons(fstsplit(m, st_1), in_2), st_2, in_3, st_3, m), sndsplit^#(m, st_1), fstsplit^#(m, st_1)) , 26: if_2^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_26(if_3^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_2))), empty^#(fstsplit(m, st_2)), fstsplit^#(m, st_2)) , 27: if_2^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_27(if_4^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(two(), head(in_2)), st_2)))), empty^#(fstsplit(m, app(map_f(two(), head(in_2)), st_2))), fstsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), head^#(in_2)) , 28: if_5^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_30(ring^#(st_1, tail(in_2), st_2, in_3, st_3, m), tail^#(in_2)) , 29: if_6^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_31(if_7^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_3))), empty^#(fstsplit(m, st_3)), fstsplit^#(m, st_3)) , 30: if_6^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_32(if_8^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(three(), head(in_3)), st_3)))), empty^#(fstsplit(m, app(map_f(three(), head(in_3)), st_3))), fstsplit^#(m, app(map_f(three(), head(in_3)), st_3)), app^#(map_f(three(), head(in_3)), st_3), map_f^#(three(), head(in_3)), head^#(in_3)) , 31: if_9^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_35(ring^#(st_1, in_2, st_2, tail(in_3), st_3, m), tail^#(in_3)) , 32: if_3^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_28(ring^#(st_1, in_2, sndsplit(m, st_2), cons(fstsplit(m, st_2), in_3), st_3, m), sndsplit^#(m, st_2), fstsplit^#(m, st_2)) , 33: if_4^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_29(ring^#(st_1, tail(in_2), sndsplit(m, app(map_f(two(), head(in_2)), st_2)), cons(fstsplit(m, app(map_f(two(), head(in_2)), st_2)), in_3), st_3, m), tail^#(in_2), sndsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), head^#(in_2), fstsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), head^#(in_2)) , 34: if_7^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_33(ring^#(st_1, in_2, st_2, in_3, sndsplit(m, st_3), m), sndsplit^#(m, st_3)) , 35: if_8^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_34(ring^#(st_1, in_2, st_2, tail(in_3), sndsplit(m, app(map_f(three(), head(in_3)), st_3)), m), tail^#(in_3), sndsplit^#(m, app(map_f(three(), head(in_3)), st_3)), app^#(map_f(three(), head(in_3)), st_3), map_f^#(three(), head(in_3)), head^#(in_3)) } We are left with following problem, upon which TcT provides the certificate MAYBE. Strict DPs: { fstsplit^#(s(n), cons(h, t)) -> c_3(fstsplit^#(n, t)) , sndsplit^#(s(n), cons(h, t)) -> c_6(sndsplit^#(n, t)) , leq^#(s(n), s(m)) -> c_11(leq^#(n, m)) , length^#(cons(h, t)) -> c_13(length^#(t)) , app^#(cons(h, t), x) -> c_15(app^#(t, x)) , map_f^#(pid, cons(h, t)) -> c_17(app^#(f(pid, h), map_f(pid, t)), map_f^#(pid, t)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_20(if_1^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_1))), empty^#(fstsplit(m, st_1)), fstsplit^#(m, st_1)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_21(if_2^#(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_2))), leq^#(m, length(st_2)), length^#(st_2)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_22(if_5^#(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(two(), head(in_2)))), empty^#(map_f(two(), head(in_2))), map_f^#(two(), head(in_2)), head^#(in_2)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_23(if_6^#(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_3))), leq^#(m, length(st_3)), length^#(st_3)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_24(if_9^#(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(three(), head(in_3)))), empty^#(map_f(three(), head(in_3))), map_f^#(three(), head(in_3)), head^#(in_3)) , if_1^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_25(ring^#(sndsplit(m, st_1), cons(fstsplit(m, st_1), in_2), st_2, in_3, st_3, m), sndsplit^#(m, st_1), fstsplit^#(m, st_1)) , if_2^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_26(if_3^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_2))), empty^#(fstsplit(m, st_2)), fstsplit^#(m, st_2)) , if_2^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_27(if_4^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(two(), head(in_2)), st_2)))), empty^#(fstsplit(m, app(map_f(two(), head(in_2)), st_2))), fstsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), head^#(in_2)) , if_5^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_30(ring^#(st_1, tail(in_2), st_2, in_3, st_3, m), tail^#(in_2)) , if_6^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_31(if_7^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_3))), empty^#(fstsplit(m, st_3)), fstsplit^#(m, st_3)) , if_6^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_32(if_8^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(three(), head(in_3)), st_3)))), empty^#(fstsplit(m, app(map_f(three(), head(in_3)), st_3))), fstsplit^#(m, app(map_f(three(), head(in_3)), st_3)), app^#(map_f(three(), head(in_3)), st_3), map_f^#(three(), head(in_3)), head^#(in_3)) , if_9^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_35(ring^#(st_1, in_2, st_2, tail(in_3), st_3, m), tail^#(in_3)) , if_3^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_28(ring^#(st_1, in_2, sndsplit(m, st_2), cons(fstsplit(m, st_2), in_3), st_3, m), sndsplit^#(m, st_2), fstsplit^#(m, st_2)) , if_4^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_29(ring^#(st_1, tail(in_2), sndsplit(m, app(map_f(two(), head(in_2)), st_2)), cons(fstsplit(m, app(map_f(two(), head(in_2)), st_2)), in_3), st_3, m), tail^#(in_2), sndsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), head^#(in_2), fstsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), head^#(in_2)) , if_7^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_33(ring^#(st_1, in_2, st_2, in_3, sndsplit(m, st_3), m), sndsplit^#(m, st_3)) , if_8^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_34(ring^#(st_1, in_2, st_2, tail(in_3), sndsplit(m, app(map_f(three(), head(in_3)), st_3)), m), tail^#(in_3), sndsplit^#(m, app(map_f(three(), head(in_3)), st_3)), app^#(map_f(three(), head(in_3)), st_3), map_f^#(three(), head(in_3)), head^#(in_3)) } Weak DPs: { fstsplit^#(0(), x) -> c_1() , fstsplit^#(s(n), nil()) -> c_2() , sndsplit^#(0(), x) -> c_4() , sndsplit^#(s(n), nil()) -> c_5() , empty^#(nil()) -> c_7() , empty^#(cons(h, t)) -> c_8() , leq^#(0(), m) -> c_9() , leq^#(s(n), 0()) -> c_10() , length^#(nil()) -> c_12() , app^#(nil(), x) -> c_14() , map_f^#(pid, nil()) -> c_16() , head^#(cons(h, t)) -> c_18() , tail^#(cons(h, t)) -> c_19() } Weak Trs: { fstsplit(0(), x) -> nil() , fstsplit(s(n), nil()) -> nil() , fstsplit(s(n), cons(h, t)) -> cons(h, fstsplit(n, t)) , sndsplit(0(), x) -> x , sndsplit(s(n), nil()) -> nil() , sndsplit(s(n), cons(h, t)) -> sndsplit(n, t) , empty(nil()) -> true() , empty(cons(h, t)) -> false() , leq(0(), m) -> true() , leq(s(n), 0()) -> false() , leq(s(n), s(m)) -> leq(n, m) , length(nil()) -> 0() , length(cons(h, t)) -> s(length(t)) , app(nil(), x) -> x , app(cons(h, t), x) -> cons(h, app(t, x)) , map_f(pid, nil()) -> nil() , map_f(pid, cons(h, t)) -> app(f(pid, h), map_f(pid, t)) , head(cons(h, t)) -> h , tail(cons(h, t)) -> t , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_1(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_1))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_2(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_2))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_5(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(two(), head(in_2)))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_6(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_3))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_9(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(three(), head(in_3)))) , if_1(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(sndsplit(m, st_1), cons(fstsplit(m, st_1), in_2), st_2, in_3, st_3, m) , if_2(st_1, in_2, st_2, in_3, st_3, m, true()) -> if_3(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_2))) , if_2(st_1, in_2, st_2, in_3, st_3, m, false()) -> if_4(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(two(), head(in_2)), st_2)))) , if_3(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, in_2, sndsplit(m, st_2), cons(fstsplit(m, st_2), in_3), st_3, m) , if_4(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, tail(in_2), sndsplit(m, app(map_f(two(), head(in_2)), st_2)), cons(fstsplit(m, app(map_f(two(), head(in_2)), st_2)), in_3), st_3, m) , if_5(st_1, in_2, st_2, in_3, st_3, m, true()) -> ring(st_1, tail(in_2), st_2, in_3, st_3, m) , if_6(st_1, in_2, st_2, in_3, st_3, m, true()) -> if_7(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_3))) , if_6(st_1, in_2, st_2, in_3, st_3, m, false()) -> if_8(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(three(), head(in_3)), st_3)))) , if_7(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, in_2, st_2, in_3, sndsplit(m, st_3), m) , if_8(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, in_2, st_2, tail(in_3), sndsplit(m, app(map_f(three(), head(in_3)), st_3)), m) , if_9(st_1, in_2, st_2, in_3, st_3, m, true()) -> ring(st_1, in_2, st_2, tail(in_3), st_3, m) } Obligation: innermost runtime complexity Answer: MAYBE The following weak DPs constitute a sub-graph of the DG that is closed under successors. The DPs are removed. { fstsplit^#(0(), x) -> c_1() , fstsplit^#(s(n), nil()) -> c_2() , sndsplit^#(0(), x) -> c_4() , sndsplit^#(s(n), nil()) -> c_5() , empty^#(nil()) -> c_7() , empty^#(cons(h, t)) -> c_8() , leq^#(0(), m) -> c_9() , leq^#(s(n), 0()) -> c_10() , length^#(nil()) -> c_12() , app^#(nil(), x) -> c_14() , map_f^#(pid, nil()) -> c_16() , head^#(cons(h, t)) -> c_18() , tail^#(cons(h, t)) -> c_19() } We are left with following problem, upon which TcT provides the certificate MAYBE. Strict DPs: { fstsplit^#(s(n), cons(h, t)) -> c_3(fstsplit^#(n, t)) , sndsplit^#(s(n), cons(h, t)) -> c_6(sndsplit^#(n, t)) , leq^#(s(n), s(m)) -> c_11(leq^#(n, m)) , length^#(cons(h, t)) -> c_13(length^#(t)) , app^#(cons(h, t), x) -> c_15(app^#(t, x)) , map_f^#(pid, cons(h, t)) -> c_17(app^#(f(pid, h), map_f(pid, t)), map_f^#(pid, t)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_20(if_1^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_1))), empty^#(fstsplit(m, st_1)), fstsplit^#(m, st_1)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_21(if_2^#(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_2))), leq^#(m, length(st_2)), length^#(st_2)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_22(if_5^#(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(two(), head(in_2)))), empty^#(map_f(two(), head(in_2))), map_f^#(two(), head(in_2)), head^#(in_2)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_23(if_6^#(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_3))), leq^#(m, length(st_3)), length^#(st_3)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_24(if_9^#(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(three(), head(in_3)))), empty^#(map_f(three(), head(in_3))), map_f^#(three(), head(in_3)), head^#(in_3)) , if_1^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_25(ring^#(sndsplit(m, st_1), cons(fstsplit(m, st_1), in_2), st_2, in_3, st_3, m), sndsplit^#(m, st_1), fstsplit^#(m, st_1)) , if_2^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_26(if_3^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_2))), empty^#(fstsplit(m, st_2)), fstsplit^#(m, st_2)) , if_2^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_27(if_4^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(two(), head(in_2)), st_2)))), empty^#(fstsplit(m, app(map_f(two(), head(in_2)), st_2))), fstsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), head^#(in_2)) , if_5^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_30(ring^#(st_1, tail(in_2), st_2, in_3, st_3, m), tail^#(in_2)) , if_6^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_31(if_7^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_3))), empty^#(fstsplit(m, st_3)), fstsplit^#(m, st_3)) , if_6^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_32(if_8^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(three(), head(in_3)), st_3)))), empty^#(fstsplit(m, app(map_f(three(), head(in_3)), st_3))), fstsplit^#(m, app(map_f(three(), head(in_3)), st_3)), app^#(map_f(three(), head(in_3)), st_3), map_f^#(three(), head(in_3)), head^#(in_3)) , if_9^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_35(ring^#(st_1, in_2, st_2, tail(in_3), st_3, m), tail^#(in_3)) , if_3^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_28(ring^#(st_1, in_2, sndsplit(m, st_2), cons(fstsplit(m, st_2), in_3), st_3, m), sndsplit^#(m, st_2), fstsplit^#(m, st_2)) , if_4^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_29(ring^#(st_1, tail(in_2), sndsplit(m, app(map_f(two(), head(in_2)), st_2)), cons(fstsplit(m, app(map_f(two(), head(in_2)), st_2)), in_3), st_3, m), tail^#(in_2), sndsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), head^#(in_2), fstsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), head^#(in_2)) , if_7^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_33(ring^#(st_1, in_2, st_2, in_3, sndsplit(m, st_3), m), sndsplit^#(m, st_3)) , if_8^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_34(ring^#(st_1, in_2, st_2, tail(in_3), sndsplit(m, app(map_f(three(), head(in_3)), st_3)), m), tail^#(in_3), sndsplit^#(m, app(map_f(three(), head(in_3)), st_3)), app^#(map_f(three(), head(in_3)), st_3), map_f^#(three(), head(in_3)), head^#(in_3)) } Weak Trs: { fstsplit(0(), x) -> nil() , fstsplit(s(n), nil()) -> nil() , fstsplit(s(n), cons(h, t)) -> cons(h, fstsplit(n, t)) , sndsplit(0(), x) -> x , sndsplit(s(n), nil()) -> nil() , sndsplit(s(n), cons(h, t)) -> sndsplit(n, t) , empty(nil()) -> true() , empty(cons(h, t)) -> false() , leq(0(), m) -> true() , leq(s(n), 0()) -> false() , leq(s(n), s(m)) -> leq(n, m) , length(nil()) -> 0() , length(cons(h, t)) -> s(length(t)) , app(nil(), x) -> x , app(cons(h, t), x) -> cons(h, app(t, x)) , map_f(pid, nil()) -> nil() , map_f(pid, cons(h, t)) -> app(f(pid, h), map_f(pid, t)) , head(cons(h, t)) -> h , tail(cons(h, t)) -> t , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_1(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_1))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_2(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_2))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_5(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(two(), head(in_2)))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_6(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_3))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_9(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(three(), head(in_3)))) , if_1(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(sndsplit(m, st_1), cons(fstsplit(m, st_1), in_2), st_2, in_3, st_3, m) , if_2(st_1, in_2, st_2, in_3, st_3, m, true()) -> if_3(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_2))) , if_2(st_1, in_2, st_2, in_3, st_3, m, false()) -> if_4(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(two(), head(in_2)), st_2)))) , if_3(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, in_2, sndsplit(m, st_2), cons(fstsplit(m, st_2), in_3), st_3, m) , if_4(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, tail(in_2), sndsplit(m, app(map_f(two(), head(in_2)), st_2)), cons(fstsplit(m, app(map_f(two(), head(in_2)), st_2)), in_3), st_3, m) , if_5(st_1, in_2, st_2, in_3, st_3, m, true()) -> ring(st_1, tail(in_2), st_2, in_3, st_3, m) , if_6(st_1, in_2, st_2, in_3, st_3, m, true()) -> if_7(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_3))) , if_6(st_1, in_2, st_2, in_3, st_3, m, false()) -> if_8(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(three(), head(in_3)), st_3)))) , if_7(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, in_2, st_2, in_3, sndsplit(m, st_3), m) , if_8(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, in_2, st_2, tail(in_3), sndsplit(m, app(map_f(three(), head(in_3)), st_3)), m) , if_9(st_1, in_2, st_2, in_3, st_3, m, true()) -> ring(st_1, in_2, st_2, tail(in_3), st_3, m) } Obligation: innermost runtime complexity Answer: MAYBE Due to missing edges in the dependency-graph, the right-hand sides of following rules could be simplified: { map_f^#(pid, cons(h, t)) -> c_17(app^#(f(pid, h), map_f(pid, t)), map_f^#(pid, t)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_20(if_1^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_1))), empty^#(fstsplit(m, st_1)), fstsplit^#(m, st_1)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_22(if_5^#(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(two(), head(in_2)))), empty^#(map_f(two(), head(in_2))), map_f^#(two(), head(in_2)), head^#(in_2)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_24(if_9^#(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(three(), head(in_3)))), empty^#(map_f(three(), head(in_3))), map_f^#(three(), head(in_3)), head^#(in_3)) , if_2^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_26(if_3^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_2))), empty^#(fstsplit(m, st_2)), fstsplit^#(m, st_2)) , if_2^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_27(if_4^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(two(), head(in_2)), st_2)))), empty^#(fstsplit(m, app(map_f(two(), head(in_2)), st_2))), fstsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), head^#(in_2)) , if_5^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_30(ring^#(st_1, tail(in_2), st_2, in_3, st_3, m), tail^#(in_2)) , if_6^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_31(if_7^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_3))), empty^#(fstsplit(m, st_3)), fstsplit^#(m, st_3)) , if_6^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_32(if_8^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(three(), head(in_3)), st_3)))), empty^#(fstsplit(m, app(map_f(three(), head(in_3)), st_3))), fstsplit^#(m, app(map_f(three(), head(in_3)), st_3)), app^#(map_f(three(), head(in_3)), st_3), map_f^#(three(), head(in_3)), head^#(in_3)) , if_9^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_35(ring^#(st_1, in_2, st_2, tail(in_3), st_3, m), tail^#(in_3)) , if_4^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_29(ring^#(st_1, tail(in_2), sndsplit(m, app(map_f(two(), head(in_2)), st_2)), cons(fstsplit(m, app(map_f(two(), head(in_2)), st_2)), in_3), st_3, m), tail^#(in_2), sndsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), head^#(in_2), fstsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), head^#(in_2)) , if_8^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_34(ring^#(st_1, in_2, st_2, tail(in_3), sndsplit(m, app(map_f(three(), head(in_3)), st_3)), m), tail^#(in_3), sndsplit^#(m, app(map_f(three(), head(in_3)), st_3)), app^#(map_f(three(), head(in_3)), st_3), map_f^#(three(), head(in_3)), head^#(in_3)) } We are left with following problem, upon which TcT provides the certificate MAYBE. Strict DPs: { fstsplit^#(s(n), cons(h, t)) -> c_1(fstsplit^#(n, t)) , sndsplit^#(s(n), cons(h, t)) -> c_2(sndsplit^#(n, t)) , leq^#(s(n), s(m)) -> c_3(leq^#(n, m)) , length^#(cons(h, t)) -> c_4(length^#(t)) , app^#(cons(h, t), x) -> c_5(app^#(t, x)) , map_f^#(pid, cons(h, t)) -> c_6(map_f^#(pid, t)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_7(if_2^#(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_2))), leq^#(m, length(st_2)), length^#(st_2)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_8(if_6^#(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_3))), leq^#(m, length(st_3)), length^#(st_3)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_9(if_1^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_1))), fstsplit^#(m, st_1)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_10(if_5^#(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(two(), head(in_2)))), map_f^#(two(), head(in_2))) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_11(if_9^#(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(three(), head(in_3)))), map_f^#(three(), head(in_3))) , if_1^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_12(ring^#(sndsplit(m, st_1), cons(fstsplit(m, st_1), in_2), st_2, in_3, st_3, m), sndsplit^#(m, st_1), fstsplit^#(m, st_1)) , if_2^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_13(if_3^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_2))), fstsplit^#(m, st_2)) , if_2^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_14(if_4^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(two(), head(in_2)), st_2)))), fstsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2))) , if_5^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_15(ring^#(st_1, tail(in_2), st_2, in_3, st_3, m)) , if_6^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_16(if_7^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_3))), fstsplit^#(m, st_3)) , if_6^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_17(if_8^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(three(), head(in_3)), st_3)))), fstsplit^#(m, app(map_f(three(), head(in_3)), st_3)), app^#(map_f(three(), head(in_3)), st_3), map_f^#(three(), head(in_3))) , if_9^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_18(ring^#(st_1, in_2, st_2, tail(in_3), st_3, m)) , if_3^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_19(ring^#(st_1, in_2, sndsplit(m, st_2), cons(fstsplit(m, st_2), in_3), st_3, m), sndsplit^#(m, st_2), fstsplit^#(m, st_2)) , if_4^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_20(ring^#(st_1, tail(in_2), sndsplit(m, app(map_f(two(), head(in_2)), st_2)), cons(fstsplit(m, app(map_f(two(), head(in_2)), st_2)), in_3), st_3, m), sndsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), fstsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2))) , if_7^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_21(ring^#(st_1, in_2, st_2, in_3, sndsplit(m, st_3), m), sndsplit^#(m, st_3)) , if_8^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_22(ring^#(st_1, in_2, st_2, tail(in_3), sndsplit(m, app(map_f(three(), head(in_3)), st_3)), m), sndsplit^#(m, app(map_f(three(), head(in_3)), st_3)), app^#(map_f(three(), head(in_3)), st_3), map_f^#(three(), head(in_3))) } Weak Trs: { fstsplit(0(), x) -> nil() , fstsplit(s(n), nil()) -> nil() , fstsplit(s(n), cons(h, t)) -> cons(h, fstsplit(n, t)) , sndsplit(0(), x) -> x , sndsplit(s(n), nil()) -> nil() , sndsplit(s(n), cons(h, t)) -> sndsplit(n, t) , empty(nil()) -> true() , empty(cons(h, t)) -> false() , leq(0(), m) -> true() , leq(s(n), 0()) -> false() , leq(s(n), s(m)) -> leq(n, m) , length(nil()) -> 0() , length(cons(h, t)) -> s(length(t)) , app(nil(), x) -> x , app(cons(h, t), x) -> cons(h, app(t, x)) , map_f(pid, nil()) -> nil() , map_f(pid, cons(h, t)) -> app(f(pid, h), map_f(pid, t)) , head(cons(h, t)) -> h , tail(cons(h, t)) -> t , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_1(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_1))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_2(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_2))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_5(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(two(), head(in_2)))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_6(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_3))) , ring(st_1, in_2, st_2, in_3, st_3, m) -> if_9(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(three(), head(in_3)))) , if_1(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(sndsplit(m, st_1), cons(fstsplit(m, st_1), in_2), st_2, in_3, st_3, m) , if_2(st_1, in_2, st_2, in_3, st_3, m, true()) -> if_3(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_2))) , if_2(st_1, in_2, st_2, in_3, st_3, m, false()) -> if_4(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(two(), head(in_2)), st_2)))) , if_3(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, in_2, sndsplit(m, st_2), cons(fstsplit(m, st_2), in_3), st_3, m) , if_4(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, tail(in_2), sndsplit(m, app(map_f(two(), head(in_2)), st_2)), cons(fstsplit(m, app(map_f(two(), head(in_2)), st_2)), in_3), st_3, m) , if_5(st_1, in_2, st_2, in_3, st_3, m, true()) -> ring(st_1, tail(in_2), st_2, in_3, st_3, m) , if_6(st_1, in_2, st_2, in_3, st_3, m, true()) -> if_7(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_3))) , if_6(st_1, in_2, st_2, in_3, st_3, m, false()) -> if_8(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(three(), head(in_3)), st_3)))) , if_7(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, in_2, st_2, in_3, sndsplit(m, st_3), m) , if_8(st_1, in_2, st_2, in_3, st_3, m, false()) -> ring(st_1, in_2, st_2, tail(in_3), sndsplit(m, app(map_f(three(), head(in_3)), st_3)), m) , if_9(st_1, in_2, st_2, in_3, st_3, m, true()) -> ring(st_1, in_2, st_2, tail(in_3), st_3, m) } Obligation: innermost runtime complexity Answer: MAYBE We replace rewrite rules by usable rules: Weak Usable Rules: { fstsplit(0(), x) -> nil() , fstsplit(s(n), nil()) -> nil() , fstsplit(s(n), cons(h, t)) -> cons(h, fstsplit(n, t)) , sndsplit(0(), x) -> x , sndsplit(s(n), nil()) -> nil() , sndsplit(s(n), cons(h, t)) -> sndsplit(n, t) , empty(nil()) -> true() , empty(cons(h, t)) -> false() , leq(0(), m) -> true() , leq(s(n), 0()) -> false() , leq(s(n), s(m)) -> leq(n, m) , length(nil()) -> 0() , length(cons(h, t)) -> s(length(t)) , app(nil(), x) -> x , app(cons(h, t), x) -> cons(h, app(t, x)) , map_f(pid, nil()) -> nil() , map_f(pid, cons(h, t)) -> app(f(pid, h), map_f(pid, t)) , head(cons(h, t)) -> h , tail(cons(h, t)) -> t } We are left with following problem, upon which TcT provides the certificate MAYBE. Strict DPs: { fstsplit^#(s(n), cons(h, t)) -> c_1(fstsplit^#(n, t)) , sndsplit^#(s(n), cons(h, t)) -> c_2(sndsplit^#(n, t)) , leq^#(s(n), s(m)) -> c_3(leq^#(n, m)) , length^#(cons(h, t)) -> c_4(length^#(t)) , app^#(cons(h, t), x) -> c_5(app^#(t, x)) , map_f^#(pid, cons(h, t)) -> c_6(map_f^#(pid, t)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_7(if_2^#(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_2))), leq^#(m, length(st_2)), length^#(st_2)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_8(if_6^#(st_1, in_2, st_2, in_3, st_3, m, leq(m, length(st_3))), leq^#(m, length(st_3)), length^#(st_3)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_9(if_1^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_1))), fstsplit^#(m, st_1)) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_10(if_5^#(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(two(), head(in_2)))), map_f^#(two(), head(in_2))) , ring^#(st_1, in_2, st_2, in_3, st_3, m) -> c_11(if_9^#(st_1, in_2, st_2, in_3, st_3, m, empty(map_f(three(), head(in_3)))), map_f^#(three(), head(in_3))) , if_1^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_12(ring^#(sndsplit(m, st_1), cons(fstsplit(m, st_1), in_2), st_2, in_3, st_3, m), sndsplit^#(m, st_1), fstsplit^#(m, st_1)) , if_2^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_13(if_3^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_2))), fstsplit^#(m, st_2)) , if_2^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_14(if_4^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(two(), head(in_2)), st_2)))), fstsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2))) , if_5^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_15(ring^#(st_1, tail(in_2), st_2, in_3, st_3, m)) , if_6^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_16(if_7^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, st_3))), fstsplit^#(m, st_3)) , if_6^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_17(if_8^#(st_1, in_2, st_2, in_3, st_3, m, empty(fstsplit(m, app(map_f(three(), head(in_3)), st_3)))), fstsplit^#(m, app(map_f(three(), head(in_3)), st_3)), app^#(map_f(three(), head(in_3)), st_3), map_f^#(three(), head(in_3))) , if_9^#(st_1, in_2, st_2, in_3, st_3, m, true()) -> c_18(ring^#(st_1, in_2, st_2, tail(in_3), st_3, m)) , if_3^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_19(ring^#(st_1, in_2, sndsplit(m, st_2), cons(fstsplit(m, st_2), in_3), st_3, m), sndsplit^#(m, st_2), fstsplit^#(m, st_2)) , if_4^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_20(ring^#(st_1, tail(in_2), sndsplit(m, app(map_f(two(), head(in_2)), st_2)), cons(fstsplit(m, app(map_f(two(), head(in_2)), st_2)), in_3), st_3, m), sndsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2)), fstsplit^#(m, app(map_f(two(), head(in_2)), st_2)), app^#(map_f(two(), head(in_2)), st_2), map_f^#(two(), head(in_2))) , if_7^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_21(ring^#(st_1, in_2, st_2, in_3, sndsplit(m, st_3), m), sndsplit^#(m, st_3)) , if_8^#(st_1, in_2, st_2, in_3, st_3, m, false()) -> c_22(ring^#(st_1, in_2, st_2, tail(in_3), sndsplit(m, app(map_f(three(), head(in_3)), st_3)), m), sndsplit^#(m, app(map_f(three(), head(in_3)), st_3)), app^#(map_f(three(), head(in_3)), st_3), map_f^#(three(), head(in_3))) } Weak Trs: { fstsplit(0(), x) -> nil() , fstsplit(s(n), nil()) -> nil() , fstsplit(s(n), cons(h, t)) -> cons(h, fstsplit(n, t)) , sndsplit(0(), x) -> x , sndsplit(s(n), nil()) -> nil() , sndsplit(s(n), cons(h, t)) -> sndsplit(n, t) , empty(nil()) -> true() , empty(cons(h, t)) -> false() , leq(0(), m) -> true() , leq(s(n), 0()) -> false() , leq(s(n), s(m)) -> leq(n, m) , length(nil()) -> 0() , length(cons(h, t)) -> s(length(t)) , app(nil(), x) -> x , app(cons(h, t), x) -> cons(h, app(t, x)) , map_f(pid, nil()) -> nil() , map_f(pid, cons(h, t)) -> app(f(pid, h), map_f(pid, t)) , head(cons(h, t)) -> h , tail(cons(h, t)) -> t } Obligation: innermost runtime complexity Answer: MAYBE The input cannot be shown compatible Arrrr..