MAYBE We are left with following problem, upon which TcT provides the certificate MAYBE. Strict Trs: { a__and(X1, X2) -> and(X1, X2) , a__and(tt(), T) -> mark(T) , mark(tt()) -> tt() , mark(0()) -> 0() , mark(s(X)) -> s(mark(X)) , mark(length(X)) -> a__length(mark(X)) , mark(zeros()) -> a__zeros() , mark(cons(X1, X2)) -> cons(mark(X1), X2) , mark(nil()) -> nil() , mark(take(X1, X2)) -> a__take(mark(X1), mark(X2)) , mark(and(X1, X2)) -> a__and(mark(X1), mark(X2)) , mark(isNatIList(X)) -> a__isNatIList(X) , mark(isNatList(X)) -> a__isNatList(X) , mark(isNat(X)) -> a__isNat(X) , mark(uTake1(X)) -> a__uTake1(mark(X)) , mark(uTake2(X1, X2, X3, X4)) -> a__uTake2(mark(X1), X2, X3, X4) , mark(uLength(X1, X2)) -> a__uLength(mark(X1), X2) , a__isNatIList(IL) -> a__isNatList(IL) , a__isNatIList(X) -> isNatIList(X) , a__isNatIList(zeros()) -> tt() , a__isNatIList(cons(N, IL)) -> a__and(a__isNat(N), a__isNatIList(IL)) , a__isNatList(X) -> isNatList(X) , a__isNatList(cons(N, L)) -> a__and(a__isNat(N), a__isNatList(L)) , a__isNatList(nil()) -> tt() , a__isNatList(take(N, IL)) -> a__and(a__isNat(N), a__isNatIList(IL)) , a__isNat(X) -> isNat(X) , a__isNat(0()) -> tt() , a__isNat(s(N)) -> a__isNat(N) , a__isNat(length(L)) -> a__isNatList(L) , a__zeros() -> zeros() , a__zeros() -> cons(0(), zeros()) , a__take(X1, X2) -> take(X1, X2) , a__take(0(), IL) -> a__uTake1(a__isNatIList(IL)) , a__take(s(M), cons(N, IL)) -> a__uTake2(a__and(a__isNat(M), a__and(a__isNat(N), a__isNatIList(IL))), M, N, IL) , a__uTake1(X) -> uTake1(X) , a__uTake1(tt()) -> nil() , a__uTake2(X1, X2, X3, X4) -> uTake2(X1, X2, X3, X4) , a__uTake2(tt(), M, N, IL) -> cons(mark(N), take(M, IL)) , a__length(X) -> length(X) , a__length(cons(N, L)) -> a__uLength(a__and(a__isNat(N), a__isNatList(L)), L) , a__uLength(X1, X2) -> uLength(X1, X2) , a__uLength(tt(), L) -> s(a__length(mark(L))) } Obligation: runtime complexity Answer: MAYBE 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) '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. 3) 'Best' failed due to the following reason: None of the processors succeeded. Details of failed attempt(s): ----------------------------- 1) 'Polynomial Path Order (PS) (timeout of 60 seconds)' failed due to the following reason: The processor is inapplicable, reason: Processor only applicable for innermost runtime complexity analysis 2) 'bsearch-popstar (timeout of 60 seconds)' failed due to the following reason: The processor is inapplicable, reason: Processor only applicable for innermost runtime complexity analysis 3) 'Innermost Weak Dependency Pairs (timeout of 60 seconds)' failed due to the following reason: We add the following weak dependency pairs: Strict DPs: { a__and^#(X1, X2) -> c_1(X1, X2) , a__and^#(tt(), T) -> c_2(mark^#(T)) , mark^#(tt()) -> c_3() , mark^#(0()) -> c_4() , mark^#(s(X)) -> c_5(mark^#(X)) , mark^#(length(X)) -> c_6(a__length^#(mark(X))) , mark^#(zeros()) -> c_7(a__zeros^#()) , mark^#(cons(X1, X2)) -> c_8(mark^#(X1), X2) , mark^#(nil()) -> c_9() , mark^#(take(X1, X2)) -> c_10(a__take^#(mark(X1), mark(X2))) , mark^#(and(X1, X2)) -> c_11(a__and^#(mark(X1), mark(X2))) , mark^#(isNatIList(X)) -> c_12(a__isNatIList^#(X)) , mark^#(isNatList(X)) -> c_13(a__isNatList^#(X)) , mark^#(isNat(X)) -> c_14(a__isNat^#(X)) , mark^#(uTake1(X)) -> c_15(a__uTake1^#(mark(X))) , mark^#(uTake2(X1, X2, X3, X4)) -> c_16(a__uTake2^#(mark(X1), X2, X3, X4)) , mark^#(uLength(X1, X2)) -> c_17(a__uLength^#(mark(X1), X2)) , a__length^#(X) -> c_39(X) , a__length^#(cons(N, L)) -> c_40(a__uLength^#(a__and(a__isNat(N), a__isNatList(L)), L)) , a__zeros^#() -> c_30() , a__zeros^#() -> c_31() , a__take^#(X1, X2) -> c_32(X1, X2) , a__take^#(0(), IL) -> c_33(a__uTake1^#(a__isNatIList(IL))) , a__take^#(s(M), cons(N, IL)) -> c_34(a__uTake2^#(a__and(a__isNat(M), a__and(a__isNat(N), a__isNatIList(IL))), M, N, IL)) , a__isNatIList^#(IL) -> c_18(a__isNatList^#(IL)) , a__isNatIList^#(X) -> c_19(X) , a__isNatIList^#(zeros()) -> c_20() , a__isNatIList^#(cons(N, IL)) -> c_21(a__and^#(a__isNat(N), a__isNatIList(IL))) , a__isNatList^#(X) -> c_22(X) , a__isNatList^#(cons(N, L)) -> c_23(a__and^#(a__isNat(N), a__isNatList(L))) , a__isNatList^#(nil()) -> c_24() , a__isNatList^#(take(N, IL)) -> c_25(a__and^#(a__isNat(N), a__isNatIList(IL))) , a__isNat^#(X) -> c_26(X) , a__isNat^#(0()) -> c_27() , a__isNat^#(s(N)) -> c_28(a__isNat^#(N)) , a__isNat^#(length(L)) -> c_29(a__isNatList^#(L)) , a__uTake1^#(X) -> c_35(X) , a__uTake1^#(tt()) -> c_36() , a__uTake2^#(X1, X2, X3, X4) -> c_37(X1, X2, X3, X4) , a__uTake2^#(tt(), M, N, IL) -> c_38(mark^#(N), M, IL) , a__uLength^#(X1, X2) -> c_41(X1, X2) , a__uLength^#(tt(), L) -> c_42(a__length^#(mark(L))) } and mark the set of starting terms. We are left with following problem, upon which TcT provides the certificate MAYBE. Strict DPs: { a__and^#(X1, X2) -> c_1(X1, X2) , a__and^#(tt(), T) -> c_2(mark^#(T)) , mark^#(tt()) -> c_3() , mark^#(0()) -> c_4() , mark^#(s(X)) -> c_5(mark^#(X)) , mark^#(length(X)) -> c_6(a__length^#(mark(X))) , mark^#(zeros()) -> c_7(a__zeros^#()) , mark^#(cons(X1, X2)) -> c_8(mark^#(X1), X2) , mark^#(nil()) -> c_9() , mark^#(take(X1, X2)) -> c_10(a__take^#(mark(X1), mark(X2))) , mark^#(and(X1, X2)) -> c_11(a__and^#(mark(X1), mark(X2))) , mark^#(isNatIList(X)) -> c_12(a__isNatIList^#(X)) , mark^#(isNatList(X)) -> c_13(a__isNatList^#(X)) , mark^#(isNat(X)) -> c_14(a__isNat^#(X)) , mark^#(uTake1(X)) -> c_15(a__uTake1^#(mark(X))) , mark^#(uTake2(X1, X2, X3, X4)) -> c_16(a__uTake2^#(mark(X1), X2, X3, X4)) , mark^#(uLength(X1, X2)) -> c_17(a__uLength^#(mark(X1), X2)) , a__length^#(X) -> c_39(X) , a__length^#(cons(N, L)) -> c_40(a__uLength^#(a__and(a__isNat(N), a__isNatList(L)), L)) , a__zeros^#() -> c_30() , a__zeros^#() -> c_31() , a__take^#(X1, X2) -> c_32(X1, X2) , a__take^#(0(), IL) -> c_33(a__uTake1^#(a__isNatIList(IL))) , a__take^#(s(M), cons(N, IL)) -> c_34(a__uTake2^#(a__and(a__isNat(M), a__and(a__isNat(N), a__isNatIList(IL))), M, N, IL)) , a__isNatIList^#(IL) -> c_18(a__isNatList^#(IL)) , a__isNatIList^#(X) -> c_19(X) , a__isNatIList^#(zeros()) -> c_20() , a__isNatIList^#(cons(N, IL)) -> c_21(a__and^#(a__isNat(N), a__isNatIList(IL))) , a__isNatList^#(X) -> c_22(X) , a__isNatList^#(cons(N, L)) -> c_23(a__and^#(a__isNat(N), a__isNatList(L))) , a__isNatList^#(nil()) -> c_24() , a__isNatList^#(take(N, IL)) -> c_25(a__and^#(a__isNat(N), a__isNatIList(IL))) , a__isNat^#(X) -> c_26(X) , a__isNat^#(0()) -> c_27() , a__isNat^#(s(N)) -> c_28(a__isNat^#(N)) , a__isNat^#(length(L)) -> c_29(a__isNatList^#(L)) , a__uTake1^#(X) -> c_35(X) , a__uTake1^#(tt()) -> c_36() , a__uTake2^#(X1, X2, X3, X4) -> c_37(X1, X2, X3, X4) , a__uTake2^#(tt(), M, N, IL) -> c_38(mark^#(N), M, IL) , a__uLength^#(X1, X2) -> c_41(X1, X2) , a__uLength^#(tt(), L) -> c_42(a__length^#(mark(L))) } Strict Trs: { a__and(X1, X2) -> and(X1, X2) , a__and(tt(), T) -> mark(T) , mark(tt()) -> tt() , mark(0()) -> 0() , mark(s(X)) -> s(mark(X)) , mark(length(X)) -> a__length(mark(X)) , mark(zeros()) -> a__zeros() , mark(cons(X1, X2)) -> cons(mark(X1), X2) , mark(nil()) -> nil() , mark(take(X1, X2)) -> a__take(mark(X1), mark(X2)) , mark(and(X1, X2)) -> a__and(mark(X1), mark(X2)) , mark(isNatIList(X)) -> a__isNatIList(X) , mark(isNatList(X)) -> a__isNatList(X) , mark(isNat(X)) -> a__isNat(X) , mark(uTake1(X)) -> a__uTake1(mark(X)) , mark(uTake2(X1, X2, X3, X4)) -> a__uTake2(mark(X1), X2, X3, X4) , mark(uLength(X1, X2)) -> a__uLength(mark(X1), X2) , a__isNatIList(IL) -> a__isNatList(IL) , a__isNatIList(X) -> isNatIList(X) , a__isNatIList(zeros()) -> tt() , a__isNatIList(cons(N, IL)) -> a__and(a__isNat(N), a__isNatIList(IL)) , a__isNatList(X) -> isNatList(X) , a__isNatList(cons(N, L)) -> a__and(a__isNat(N), a__isNatList(L)) , a__isNatList(nil()) -> tt() , a__isNatList(take(N, IL)) -> a__and(a__isNat(N), a__isNatIList(IL)) , a__isNat(X) -> isNat(X) , a__isNat(0()) -> tt() , a__isNat(s(N)) -> a__isNat(N) , a__isNat(length(L)) -> a__isNatList(L) , a__zeros() -> zeros() , a__zeros() -> cons(0(), zeros()) , a__take(X1, X2) -> take(X1, X2) , a__take(0(), IL) -> a__uTake1(a__isNatIList(IL)) , a__take(s(M), cons(N, IL)) -> a__uTake2(a__and(a__isNat(M), a__and(a__isNat(N), a__isNatIList(IL))), M, N, IL) , a__uTake1(X) -> uTake1(X) , a__uTake1(tt()) -> nil() , a__uTake2(X1, X2, X3, X4) -> uTake2(X1, X2, X3, X4) , a__uTake2(tt(), M, N, IL) -> cons(mark(N), take(M, IL)) , a__length(X) -> length(X) , a__length(cons(N, L)) -> a__uLength(a__and(a__isNat(N), a__isNatList(L)), L) , a__uLength(X1, X2) -> uLength(X1, X2) , a__uLength(tt(), L) -> s(a__length(mark(L))) } Obligation: runtime complexity Answer: MAYBE We estimate the number of application of {3,4,9,20,21,27,31,34,38} by applications of Pre({3,4,9,20,21,27,31,34,38}) = {1,2,5,7,8,12,13,14,15,18,22,23,25,26,29,33,35,36,37,39,40,41}. Here rules are labeled as follows: DPs: { 1: a__and^#(X1, X2) -> c_1(X1, X2) , 2: a__and^#(tt(), T) -> c_2(mark^#(T)) , 3: mark^#(tt()) -> c_3() , 4: mark^#(0()) -> c_4() , 5: mark^#(s(X)) -> c_5(mark^#(X)) , 6: mark^#(length(X)) -> c_6(a__length^#(mark(X))) , 7: mark^#(zeros()) -> c_7(a__zeros^#()) , 8: mark^#(cons(X1, X2)) -> c_8(mark^#(X1), X2) , 9: mark^#(nil()) -> c_9() , 10: mark^#(take(X1, X2)) -> c_10(a__take^#(mark(X1), mark(X2))) , 11: mark^#(and(X1, X2)) -> c_11(a__and^#(mark(X1), mark(X2))) , 12: mark^#(isNatIList(X)) -> c_12(a__isNatIList^#(X)) , 13: mark^#(isNatList(X)) -> c_13(a__isNatList^#(X)) , 14: mark^#(isNat(X)) -> c_14(a__isNat^#(X)) , 15: mark^#(uTake1(X)) -> c_15(a__uTake1^#(mark(X))) , 16: mark^#(uTake2(X1, X2, X3, X4)) -> c_16(a__uTake2^#(mark(X1), X2, X3, X4)) , 17: mark^#(uLength(X1, X2)) -> c_17(a__uLength^#(mark(X1), X2)) , 18: a__length^#(X) -> c_39(X) , 19: a__length^#(cons(N, L)) -> c_40(a__uLength^#(a__and(a__isNat(N), a__isNatList(L)), L)) , 20: a__zeros^#() -> c_30() , 21: a__zeros^#() -> c_31() , 22: a__take^#(X1, X2) -> c_32(X1, X2) , 23: a__take^#(0(), IL) -> c_33(a__uTake1^#(a__isNatIList(IL))) , 24: a__take^#(s(M), cons(N, IL)) -> c_34(a__uTake2^#(a__and(a__isNat(M), a__and(a__isNat(N), a__isNatIList(IL))), M, N, IL)) , 25: a__isNatIList^#(IL) -> c_18(a__isNatList^#(IL)) , 26: a__isNatIList^#(X) -> c_19(X) , 27: a__isNatIList^#(zeros()) -> c_20() , 28: a__isNatIList^#(cons(N, IL)) -> c_21(a__and^#(a__isNat(N), a__isNatIList(IL))) , 29: a__isNatList^#(X) -> c_22(X) , 30: a__isNatList^#(cons(N, L)) -> c_23(a__and^#(a__isNat(N), a__isNatList(L))) , 31: a__isNatList^#(nil()) -> c_24() , 32: a__isNatList^#(take(N, IL)) -> c_25(a__and^#(a__isNat(N), a__isNatIList(IL))) , 33: a__isNat^#(X) -> c_26(X) , 34: a__isNat^#(0()) -> c_27() , 35: a__isNat^#(s(N)) -> c_28(a__isNat^#(N)) , 36: a__isNat^#(length(L)) -> c_29(a__isNatList^#(L)) , 37: a__uTake1^#(X) -> c_35(X) , 38: a__uTake1^#(tt()) -> c_36() , 39: a__uTake2^#(X1, X2, X3, X4) -> c_37(X1, X2, X3, X4) , 40: a__uTake2^#(tt(), M, N, IL) -> c_38(mark^#(N), M, IL) , 41: a__uLength^#(X1, X2) -> c_41(X1, X2) , 42: a__uLength^#(tt(), L) -> c_42(a__length^#(mark(L))) } We are left with following problem, upon which TcT provides the certificate MAYBE. Strict DPs: { a__and^#(X1, X2) -> c_1(X1, X2) , a__and^#(tt(), T) -> c_2(mark^#(T)) , mark^#(s(X)) -> c_5(mark^#(X)) , mark^#(length(X)) -> c_6(a__length^#(mark(X))) , mark^#(zeros()) -> c_7(a__zeros^#()) , mark^#(cons(X1, X2)) -> c_8(mark^#(X1), X2) , mark^#(take(X1, X2)) -> c_10(a__take^#(mark(X1), mark(X2))) , mark^#(and(X1, X2)) -> c_11(a__and^#(mark(X1), mark(X2))) , mark^#(isNatIList(X)) -> c_12(a__isNatIList^#(X)) , mark^#(isNatList(X)) -> c_13(a__isNatList^#(X)) , mark^#(isNat(X)) -> c_14(a__isNat^#(X)) , mark^#(uTake1(X)) -> c_15(a__uTake1^#(mark(X))) , mark^#(uTake2(X1, X2, X3, X4)) -> c_16(a__uTake2^#(mark(X1), X2, X3, X4)) , mark^#(uLength(X1, X2)) -> c_17(a__uLength^#(mark(X1), X2)) , a__length^#(X) -> c_39(X) , a__length^#(cons(N, L)) -> c_40(a__uLength^#(a__and(a__isNat(N), a__isNatList(L)), L)) , a__take^#(X1, X2) -> c_32(X1, X2) , a__take^#(0(), IL) -> c_33(a__uTake1^#(a__isNatIList(IL))) , a__take^#(s(M), cons(N, IL)) -> c_34(a__uTake2^#(a__and(a__isNat(M), a__and(a__isNat(N), a__isNatIList(IL))), M, N, IL)) , a__isNatIList^#(IL) -> c_18(a__isNatList^#(IL)) , a__isNatIList^#(X) -> c_19(X) , a__isNatIList^#(cons(N, IL)) -> c_21(a__and^#(a__isNat(N), a__isNatIList(IL))) , a__isNatList^#(X) -> c_22(X) , a__isNatList^#(cons(N, L)) -> c_23(a__and^#(a__isNat(N), a__isNatList(L))) , a__isNatList^#(take(N, IL)) -> c_25(a__and^#(a__isNat(N), a__isNatIList(IL))) , a__isNat^#(X) -> c_26(X) , a__isNat^#(s(N)) -> c_28(a__isNat^#(N)) , a__isNat^#(length(L)) -> c_29(a__isNatList^#(L)) , a__uTake1^#(X) -> c_35(X) , a__uTake2^#(X1, X2, X3, X4) -> c_37(X1, X2, X3, X4) , a__uTake2^#(tt(), M, N, IL) -> c_38(mark^#(N), M, IL) , a__uLength^#(X1, X2) -> c_41(X1, X2) , a__uLength^#(tt(), L) -> c_42(a__length^#(mark(L))) } Strict Trs: { a__and(X1, X2) -> and(X1, X2) , a__and(tt(), T) -> mark(T) , mark(tt()) -> tt() , mark(0()) -> 0() , mark(s(X)) -> s(mark(X)) , mark(length(X)) -> a__length(mark(X)) , mark(zeros()) -> a__zeros() , mark(cons(X1, X2)) -> cons(mark(X1), X2) , mark(nil()) -> nil() , mark(take(X1, X2)) -> a__take(mark(X1), mark(X2)) , mark(and(X1, X2)) -> a__and(mark(X1), mark(X2)) , mark(isNatIList(X)) -> a__isNatIList(X) , mark(isNatList(X)) -> a__isNatList(X) , mark(isNat(X)) -> a__isNat(X) , mark(uTake1(X)) -> a__uTake1(mark(X)) , mark(uTake2(X1, X2, X3, X4)) -> a__uTake2(mark(X1), X2, X3, X4) , mark(uLength(X1, X2)) -> a__uLength(mark(X1), X2) , a__isNatIList(IL) -> a__isNatList(IL) , a__isNatIList(X) -> isNatIList(X) , a__isNatIList(zeros()) -> tt() , a__isNatIList(cons(N, IL)) -> a__and(a__isNat(N), a__isNatIList(IL)) , a__isNatList(X) -> isNatList(X) , a__isNatList(cons(N, L)) -> a__and(a__isNat(N), a__isNatList(L)) , a__isNatList(nil()) -> tt() , a__isNatList(take(N, IL)) -> a__and(a__isNat(N), a__isNatIList(IL)) , a__isNat(X) -> isNat(X) , a__isNat(0()) -> tt() , a__isNat(s(N)) -> a__isNat(N) , a__isNat(length(L)) -> a__isNatList(L) , a__zeros() -> zeros() , a__zeros() -> cons(0(), zeros()) , a__take(X1, X2) -> take(X1, X2) , a__take(0(), IL) -> a__uTake1(a__isNatIList(IL)) , a__take(s(M), cons(N, IL)) -> a__uTake2(a__and(a__isNat(M), a__and(a__isNat(N), a__isNatIList(IL))), M, N, IL) , a__uTake1(X) -> uTake1(X) , a__uTake1(tt()) -> nil() , a__uTake2(X1, X2, X3, X4) -> uTake2(X1, X2, X3, X4) , a__uTake2(tt(), M, N, IL) -> cons(mark(N), take(M, IL)) , a__length(X) -> length(X) , a__length(cons(N, L)) -> a__uLength(a__and(a__isNat(N), a__isNatList(L)), L) , a__uLength(X1, X2) -> uLength(X1, X2) , a__uLength(tt(), L) -> s(a__length(mark(L))) } Weak DPs: { mark^#(tt()) -> c_3() , mark^#(0()) -> c_4() , mark^#(nil()) -> c_9() , a__zeros^#() -> c_30() , a__zeros^#() -> c_31() , a__isNatIList^#(zeros()) -> c_20() , a__isNatList^#(nil()) -> c_24() , a__isNat^#(0()) -> c_27() , a__uTake1^#(tt()) -> c_36() } Obligation: runtime complexity Answer: MAYBE We estimate the number of application of {5} by applications of Pre({5}) = {1,2,3,6,15,17,21,23,26,29,30,31,32}. Here rules are labeled as follows: DPs: { 1: a__and^#(X1, X2) -> c_1(X1, X2) , 2: a__and^#(tt(), T) -> c_2(mark^#(T)) , 3: mark^#(s(X)) -> c_5(mark^#(X)) , 4: mark^#(length(X)) -> c_6(a__length^#(mark(X))) , 5: mark^#(zeros()) -> c_7(a__zeros^#()) , 6: mark^#(cons(X1, X2)) -> c_8(mark^#(X1), X2) , 7: mark^#(take(X1, X2)) -> c_10(a__take^#(mark(X1), mark(X2))) , 8: mark^#(and(X1, X2)) -> c_11(a__and^#(mark(X1), mark(X2))) , 9: mark^#(isNatIList(X)) -> c_12(a__isNatIList^#(X)) , 10: mark^#(isNatList(X)) -> c_13(a__isNatList^#(X)) , 11: mark^#(isNat(X)) -> c_14(a__isNat^#(X)) , 12: mark^#(uTake1(X)) -> c_15(a__uTake1^#(mark(X))) , 13: mark^#(uTake2(X1, X2, X3, X4)) -> c_16(a__uTake2^#(mark(X1), X2, X3, X4)) , 14: mark^#(uLength(X1, X2)) -> c_17(a__uLength^#(mark(X1), X2)) , 15: a__length^#(X) -> c_39(X) , 16: a__length^#(cons(N, L)) -> c_40(a__uLength^#(a__and(a__isNat(N), a__isNatList(L)), L)) , 17: a__take^#(X1, X2) -> c_32(X1, X2) , 18: a__take^#(0(), IL) -> c_33(a__uTake1^#(a__isNatIList(IL))) , 19: a__take^#(s(M), cons(N, IL)) -> c_34(a__uTake2^#(a__and(a__isNat(M), a__and(a__isNat(N), a__isNatIList(IL))), M, N, IL)) , 20: a__isNatIList^#(IL) -> c_18(a__isNatList^#(IL)) , 21: a__isNatIList^#(X) -> c_19(X) , 22: a__isNatIList^#(cons(N, IL)) -> c_21(a__and^#(a__isNat(N), a__isNatIList(IL))) , 23: a__isNatList^#(X) -> c_22(X) , 24: a__isNatList^#(cons(N, L)) -> c_23(a__and^#(a__isNat(N), a__isNatList(L))) , 25: a__isNatList^#(take(N, IL)) -> c_25(a__and^#(a__isNat(N), a__isNatIList(IL))) , 26: a__isNat^#(X) -> c_26(X) , 27: a__isNat^#(s(N)) -> c_28(a__isNat^#(N)) , 28: a__isNat^#(length(L)) -> c_29(a__isNatList^#(L)) , 29: a__uTake1^#(X) -> c_35(X) , 30: a__uTake2^#(X1, X2, X3, X4) -> c_37(X1, X2, X3, X4) , 31: a__uTake2^#(tt(), M, N, IL) -> c_38(mark^#(N), M, IL) , 32: a__uLength^#(X1, X2) -> c_41(X1, X2) , 33: a__uLength^#(tt(), L) -> c_42(a__length^#(mark(L))) , 34: mark^#(tt()) -> c_3() , 35: mark^#(0()) -> c_4() , 36: mark^#(nil()) -> c_9() , 37: a__zeros^#() -> c_30() , 38: a__zeros^#() -> c_31() , 39: a__isNatIList^#(zeros()) -> c_20() , 40: a__isNatList^#(nil()) -> c_24() , 41: a__isNat^#(0()) -> c_27() , 42: a__uTake1^#(tt()) -> c_36() } We are left with following problem, upon which TcT provides the certificate MAYBE. Strict DPs: { a__and^#(X1, X2) -> c_1(X1, X2) , a__and^#(tt(), T) -> c_2(mark^#(T)) , mark^#(s(X)) -> c_5(mark^#(X)) , mark^#(length(X)) -> c_6(a__length^#(mark(X))) , mark^#(cons(X1, X2)) -> c_8(mark^#(X1), X2) , mark^#(take(X1, X2)) -> c_10(a__take^#(mark(X1), mark(X2))) , mark^#(and(X1, X2)) -> c_11(a__and^#(mark(X1), mark(X2))) , mark^#(isNatIList(X)) -> c_12(a__isNatIList^#(X)) , mark^#(isNatList(X)) -> c_13(a__isNatList^#(X)) , mark^#(isNat(X)) -> c_14(a__isNat^#(X)) , mark^#(uTake1(X)) -> c_15(a__uTake1^#(mark(X))) , mark^#(uTake2(X1, X2, X3, X4)) -> c_16(a__uTake2^#(mark(X1), X2, X3, X4)) , mark^#(uLength(X1, X2)) -> c_17(a__uLength^#(mark(X1), X2)) , a__length^#(X) -> c_39(X) , a__length^#(cons(N, L)) -> c_40(a__uLength^#(a__and(a__isNat(N), a__isNatList(L)), L)) , a__take^#(X1, X2) -> c_32(X1, X2) , a__take^#(0(), IL) -> c_33(a__uTake1^#(a__isNatIList(IL))) , a__take^#(s(M), cons(N, IL)) -> c_34(a__uTake2^#(a__and(a__isNat(M), a__and(a__isNat(N), a__isNatIList(IL))), M, N, IL)) , a__isNatIList^#(IL) -> c_18(a__isNatList^#(IL)) , a__isNatIList^#(X) -> c_19(X) , a__isNatIList^#(cons(N, IL)) -> c_21(a__and^#(a__isNat(N), a__isNatIList(IL))) , a__isNatList^#(X) -> c_22(X) , a__isNatList^#(cons(N, L)) -> c_23(a__and^#(a__isNat(N), a__isNatList(L))) , a__isNatList^#(take(N, IL)) -> c_25(a__and^#(a__isNat(N), a__isNatIList(IL))) , a__isNat^#(X) -> c_26(X) , a__isNat^#(s(N)) -> c_28(a__isNat^#(N)) , a__isNat^#(length(L)) -> c_29(a__isNatList^#(L)) , a__uTake1^#(X) -> c_35(X) , a__uTake2^#(X1, X2, X3, X4) -> c_37(X1, X2, X3, X4) , a__uTake2^#(tt(), M, N, IL) -> c_38(mark^#(N), M, IL) , a__uLength^#(X1, X2) -> c_41(X1, X2) , a__uLength^#(tt(), L) -> c_42(a__length^#(mark(L))) } Strict Trs: { a__and(X1, X2) -> and(X1, X2) , a__and(tt(), T) -> mark(T) , mark(tt()) -> tt() , mark(0()) -> 0() , mark(s(X)) -> s(mark(X)) , mark(length(X)) -> a__length(mark(X)) , mark(zeros()) -> a__zeros() , mark(cons(X1, X2)) -> cons(mark(X1), X2) , mark(nil()) -> nil() , mark(take(X1, X2)) -> a__take(mark(X1), mark(X2)) , mark(and(X1, X2)) -> a__and(mark(X1), mark(X2)) , mark(isNatIList(X)) -> a__isNatIList(X) , mark(isNatList(X)) -> a__isNatList(X) , mark(isNat(X)) -> a__isNat(X) , mark(uTake1(X)) -> a__uTake1(mark(X)) , mark(uTake2(X1, X2, X3, X4)) -> a__uTake2(mark(X1), X2, X3, X4) , mark(uLength(X1, X2)) -> a__uLength(mark(X1), X2) , a__isNatIList(IL) -> a__isNatList(IL) , a__isNatIList(X) -> isNatIList(X) , a__isNatIList(zeros()) -> tt() , a__isNatIList(cons(N, IL)) -> a__and(a__isNat(N), a__isNatIList(IL)) , a__isNatList(X) -> isNatList(X) , a__isNatList(cons(N, L)) -> a__and(a__isNat(N), a__isNatList(L)) , a__isNatList(nil()) -> tt() , a__isNatList(take(N, IL)) -> a__and(a__isNat(N), a__isNatIList(IL)) , a__isNat(X) -> isNat(X) , a__isNat(0()) -> tt() , a__isNat(s(N)) -> a__isNat(N) , a__isNat(length(L)) -> a__isNatList(L) , a__zeros() -> zeros() , a__zeros() -> cons(0(), zeros()) , a__take(X1, X2) -> take(X1, X2) , a__take(0(), IL) -> a__uTake1(a__isNatIList(IL)) , a__take(s(M), cons(N, IL)) -> a__uTake2(a__and(a__isNat(M), a__and(a__isNat(N), a__isNatIList(IL))), M, N, IL) , a__uTake1(X) -> uTake1(X) , a__uTake1(tt()) -> nil() , a__uTake2(X1, X2, X3, X4) -> uTake2(X1, X2, X3, X4) , a__uTake2(tt(), M, N, IL) -> cons(mark(N), take(M, IL)) , a__length(X) -> length(X) , a__length(cons(N, L)) -> a__uLength(a__and(a__isNat(N), a__isNatList(L)), L) , a__uLength(X1, X2) -> uLength(X1, X2) , a__uLength(tt(), L) -> s(a__length(mark(L))) } Weak DPs: { mark^#(tt()) -> c_3() , mark^#(0()) -> c_4() , mark^#(zeros()) -> c_7(a__zeros^#()) , mark^#(nil()) -> c_9() , a__zeros^#() -> c_30() , a__zeros^#() -> c_31() , a__isNatIList^#(zeros()) -> c_20() , a__isNatList^#(nil()) -> c_24() , a__isNat^#(0()) -> c_27() , a__uTake1^#(tt()) -> c_36() } Obligation: runtime complexity Answer: MAYBE Empty strict component of the problem is NOT empty. Arrrr..