MAYBE * Step 1: DependencyPairs MAYBE + Considered Problem: - Strict TRS: conv(x) -> conviter(x,cons(0(),nil())) conviter(x,l) -> if(zero(x),x,l) half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) if(false(),x,l) -> conviter(half(x),cons(lastbit(x),l)) if(true(),x,l) -> l lastbit(0()) -> 0() lastbit(s(0())) -> s(0()) lastbit(s(s(x))) -> lastbit(x) zero(0()) -> true() zero(s(x)) -> false() - Signature: {conv/1,conviter/2,half/1,if/3,lastbit/1,zero/1} / {0/0,cons/2,false/0,nil/0,s/1,true/0} - Obligation: innermost runtime complexity wrt. defined symbols {conv,conviter,half,if,lastbit,zero} and constructors {0 ,cons,false,nil,s,true} + Applied Processor: DependencyPairs {dpKind_ = DT} + Details: We add the following dependency tuples: Strict DPs conv#(x) -> c_1(conviter#(x,cons(0(),nil()))) conviter#(x,l) -> c_2(if#(zero(x),x,l),zero#(x)) half#(0()) -> c_3() half#(s(0())) -> c_4() half#(s(s(x))) -> c_5(half#(x)) if#(false(),x,l) -> c_6(conviter#(half(x),cons(lastbit(x),l)),half#(x),lastbit#(x)) if#(true(),x,l) -> c_7() lastbit#(0()) -> c_8() lastbit#(s(0())) -> c_9() lastbit#(s(s(x))) -> c_10(lastbit#(x)) zero#(0()) -> c_11() zero#(s(x)) -> c_12() Weak DPs and mark the set of starting terms. * Step 2: UsableRules MAYBE + Considered Problem: - Strict DPs: conv#(x) -> c_1(conviter#(x,cons(0(),nil()))) conviter#(x,l) -> c_2(if#(zero(x),x,l),zero#(x)) half#(0()) -> c_3() half#(s(0())) -> c_4() half#(s(s(x))) -> c_5(half#(x)) if#(false(),x,l) -> c_6(conviter#(half(x),cons(lastbit(x),l)),half#(x),lastbit#(x)) if#(true(),x,l) -> c_7() lastbit#(0()) -> c_8() lastbit#(s(0())) -> c_9() lastbit#(s(s(x))) -> c_10(lastbit#(x)) zero#(0()) -> c_11() zero#(s(x)) -> c_12() - Weak TRS: conv(x) -> conviter(x,cons(0(),nil())) conviter(x,l) -> if(zero(x),x,l) half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) if(false(),x,l) -> conviter(half(x),cons(lastbit(x),l)) if(true(),x,l) -> l lastbit(0()) -> 0() lastbit(s(0())) -> s(0()) lastbit(s(s(x))) -> lastbit(x) zero(0()) -> true() zero(s(x)) -> false() - Signature: {conv/1,conviter/2,half/1,if/3,lastbit/1,zero/1,conv#/1,conviter#/2,half#/1,if#/3,lastbit#/1,zero#/1} / {0/0 ,cons/2,false/0,nil/0,s/1,true/0,c_1/1,c_2/2,c_3/0,c_4/0,c_5/1,c_6/3,c_7/0,c_8/0,c_9/0,c_10/1,c_11/0,c_12/0} - Obligation: innermost runtime complexity wrt. defined symbols {conv#,conviter#,half#,if#,lastbit# ,zero#} and constructors {0,cons,false,nil,s,true} + Applied Processor: UsableRules + Details: We replace rewrite rules by usable rules: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) lastbit(0()) -> 0() lastbit(s(0())) -> s(0()) lastbit(s(s(x))) -> lastbit(x) zero(0()) -> true() zero(s(x)) -> false() conv#(x) -> c_1(conviter#(x,cons(0(),nil()))) conviter#(x,l) -> c_2(if#(zero(x),x,l),zero#(x)) half#(0()) -> c_3() half#(s(0())) -> c_4() half#(s(s(x))) -> c_5(half#(x)) if#(false(),x,l) -> c_6(conviter#(half(x),cons(lastbit(x),l)),half#(x),lastbit#(x)) if#(true(),x,l) -> c_7() lastbit#(0()) -> c_8() lastbit#(s(0())) -> c_9() lastbit#(s(s(x))) -> c_10(lastbit#(x)) zero#(0()) -> c_11() zero#(s(x)) -> c_12() * Step 3: PredecessorEstimation MAYBE + Considered Problem: - Strict DPs: conv#(x) -> c_1(conviter#(x,cons(0(),nil()))) conviter#(x,l) -> c_2(if#(zero(x),x,l),zero#(x)) half#(0()) -> c_3() half#(s(0())) -> c_4() half#(s(s(x))) -> c_5(half#(x)) if#(false(),x,l) -> c_6(conviter#(half(x),cons(lastbit(x),l)),half#(x),lastbit#(x)) if#(true(),x,l) -> c_7() lastbit#(0()) -> c_8() lastbit#(s(0())) -> c_9() lastbit#(s(s(x))) -> c_10(lastbit#(x)) zero#(0()) -> c_11() zero#(s(x)) -> c_12() - Weak TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) lastbit(0()) -> 0() lastbit(s(0())) -> s(0()) lastbit(s(s(x))) -> lastbit(x) zero(0()) -> true() zero(s(x)) -> false() - Signature: {conv/1,conviter/2,half/1,if/3,lastbit/1,zero/1,conv#/1,conviter#/2,half#/1,if#/3,lastbit#/1,zero#/1} / {0/0 ,cons/2,false/0,nil/0,s/1,true/0,c_1/1,c_2/2,c_3/0,c_4/0,c_5/1,c_6/3,c_7/0,c_8/0,c_9/0,c_10/1,c_11/0,c_12/0} - Obligation: innermost runtime complexity wrt. defined symbols {conv#,conviter#,half#,if#,lastbit# ,zero#} and constructors {0,cons,false,nil,s,true} + Applied Processor: PredecessorEstimation {onSelection = all simple predecessor estimation selector} + Details: We estimate the number of application of {3,4,7,8,9,11,12} by application of Pre({3,4,7,8,9,11,12}) = {2,5,6,10}. Here rules are labelled as follows: 1: conv#(x) -> c_1(conviter#(x,cons(0(),nil()))) 2: conviter#(x,l) -> c_2(if#(zero(x),x,l),zero#(x)) 3: half#(0()) -> c_3() 4: half#(s(0())) -> c_4() 5: half#(s(s(x))) -> c_5(half#(x)) 6: if#(false(),x,l) -> c_6(conviter#(half(x),cons(lastbit(x),l)),half#(x),lastbit#(x)) 7: if#(true(),x,l) -> c_7() 8: lastbit#(0()) -> c_8() 9: lastbit#(s(0())) -> c_9() 10: lastbit#(s(s(x))) -> c_10(lastbit#(x)) 11: zero#(0()) -> c_11() 12: zero#(s(x)) -> c_12() * Step 4: RemoveWeakSuffixes MAYBE + Considered Problem: - Strict DPs: conv#(x) -> c_1(conviter#(x,cons(0(),nil()))) conviter#(x,l) -> c_2(if#(zero(x),x,l),zero#(x)) half#(s(s(x))) -> c_5(half#(x)) if#(false(),x,l) -> c_6(conviter#(half(x),cons(lastbit(x),l)),half#(x),lastbit#(x)) lastbit#(s(s(x))) -> c_10(lastbit#(x)) - Weak DPs: half#(0()) -> c_3() half#(s(0())) -> c_4() if#(true(),x,l) -> c_7() lastbit#(0()) -> c_8() lastbit#(s(0())) -> c_9() zero#(0()) -> c_11() zero#(s(x)) -> c_12() - Weak TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) lastbit(0()) -> 0() lastbit(s(0())) -> s(0()) lastbit(s(s(x))) -> lastbit(x) zero(0()) -> true() zero(s(x)) -> false() - Signature: {conv/1,conviter/2,half/1,if/3,lastbit/1,zero/1,conv#/1,conviter#/2,half#/1,if#/3,lastbit#/1,zero#/1} / {0/0 ,cons/2,false/0,nil/0,s/1,true/0,c_1/1,c_2/2,c_3/0,c_4/0,c_5/1,c_6/3,c_7/0,c_8/0,c_9/0,c_10/1,c_11/0,c_12/0} - Obligation: innermost runtime complexity wrt. defined symbols {conv#,conviter#,half#,if#,lastbit# ,zero#} and constructors {0,cons,false,nil,s,true} + Applied Processor: RemoveWeakSuffixes + Details: Consider the dependency graph 1:S:conv#(x) -> c_1(conviter#(x,cons(0(),nil()))) -->_1 conviter#(x,l) -> c_2(if#(zero(x),x,l),zero#(x)):2 2:S:conviter#(x,l) -> c_2(if#(zero(x),x,l),zero#(x)) -->_1 if#(false(),x,l) -> c_6(conviter#(half(x),cons(lastbit(x),l)),half#(x),lastbit#(x)):4 -->_2 zero#(s(x)) -> c_12():12 -->_2 zero#(0()) -> c_11():11 -->_1 if#(true(),x,l) -> c_7():8 3:S:half#(s(s(x))) -> c_5(half#(x)) -->_1 half#(s(0())) -> c_4():7 -->_1 half#(0()) -> c_3():6 -->_1 half#(s(s(x))) -> c_5(half#(x)):3 4:S:if#(false(),x,l) -> c_6(conviter#(half(x),cons(lastbit(x),l)),half#(x),lastbit#(x)) -->_3 lastbit#(s(s(x))) -> c_10(lastbit#(x)):5 -->_3 lastbit#(s(0())) -> c_9():10 -->_3 lastbit#(0()) -> c_8():9 -->_2 half#(s(0())) -> c_4():7 -->_2 half#(0()) -> c_3():6 -->_2 half#(s(s(x))) -> c_5(half#(x)):3 -->_1 conviter#(x,l) -> c_2(if#(zero(x),x,l),zero#(x)):2 5:S:lastbit#(s(s(x))) -> c_10(lastbit#(x)) -->_1 lastbit#(s(0())) -> c_9():10 -->_1 lastbit#(0()) -> c_8():9 -->_1 lastbit#(s(s(x))) -> c_10(lastbit#(x)):5 6:W:half#(0()) -> c_3() 7:W:half#(s(0())) -> c_4() 8:W:if#(true(),x,l) -> c_7() 9:W:lastbit#(0()) -> c_8() 10:W:lastbit#(s(0())) -> c_9() 11:W:zero#(0()) -> c_11() 12:W:zero#(s(x)) -> c_12() The following weak DPs constitute a sub-graph of the DG that is closed under successors. The DPs are removed. 8: if#(true(),x,l) -> c_7() 11: zero#(0()) -> c_11() 12: zero#(s(x)) -> c_12() 6: half#(0()) -> c_3() 7: half#(s(0())) -> c_4() 9: lastbit#(0()) -> c_8() 10: lastbit#(s(0())) -> c_9() * Step 5: SimplifyRHS MAYBE + Considered Problem: - Strict DPs: conv#(x) -> c_1(conviter#(x,cons(0(),nil()))) conviter#(x,l) -> c_2(if#(zero(x),x,l),zero#(x)) half#(s(s(x))) -> c_5(half#(x)) if#(false(),x,l) -> c_6(conviter#(half(x),cons(lastbit(x),l)),half#(x),lastbit#(x)) lastbit#(s(s(x))) -> c_10(lastbit#(x)) - Weak TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) lastbit(0()) -> 0() lastbit(s(0())) -> s(0()) lastbit(s(s(x))) -> lastbit(x) zero(0()) -> true() zero(s(x)) -> false() - Signature: {conv/1,conviter/2,half/1,if/3,lastbit/1,zero/1,conv#/1,conviter#/2,half#/1,if#/3,lastbit#/1,zero#/1} / {0/0 ,cons/2,false/0,nil/0,s/1,true/0,c_1/1,c_2/2,c_3/0,c_4/0,c_5/1,c_6/3,c_7/0,c_8/0,c_9/0,c_10/1,c_11/0,c_12/0} - Obligation: innermost runtime complexity wrt. defined symbols {conv#,conviter#,half#,if#,lastbit# ,zero#} and constructors {0,cons,false,nil,s,true} + Applied Processor: SimplifyRHS + Details: Consider the dependency graph 1:S:conv#(x) -> c_1(conviter#(x,cons(0(),nil()))) -->_1 conviter#(x,l) -> c_2(if#(zero(x),x,l),zero#(x)):2 2:S:conviter#(x,l) -> c_2(if#(zero(x),x,l),zero#(x)) -->_1 if#(false(),x,l) -> c_6(conviter#(half(x),cons(lastbit(x),l)),half#(x),lastbit#(x)):4 3:S:half#(s(s(x))) -> c_5(half#(x)) -->_1 half#(s(s(x))) -> c_5(half#(x)):3 4:S:if#(false(),x,l) -> c_6(conviter#(half(x),cons(lastbit(x),l)),half#(x),lastbit#(x)) -->_3 lastbit#(s(s(x))) -> c_10(lastbit#(x)):5 -->_2 half#(s(s(x))) -> c_5(half#(x)):3 -->_1 conviter#(x,l) -> c_2(if#(zero(x),x,l),zero#(x)):2 5:S:lastbit#(s(s(x))) -> c_10(lastbit#(x)) -->_1 lastbit#(s(s(x))) -> c_10(lastbit#(x)):5 Due to missing edges in the depndency graph, the right-hand sides of following rules could be simplified: conviter#(x,l) -> c_2(if#(zero(x),x,l)) * Step 6: RemoveHeads MAYBE + Considered Problem: - Strict DPs: conv#(x) -> c_1(conviter#(x,cons(0(),nil()))) conviter#(x,l) -> c_2(if#(zero(x),x,l)) half#(s(s(x))) -> c_5(half#(x)) if#(false(),x,l) -> c_6(conviter#(half(x),cons(lastbit(x),l)),half#(x),lastbit#(x)) lastbit#(s(s(x))) -> c_10(lastbit#(x)) - Weak TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) lastbit(0()) -> 0() lastbit(s(0())) -> s(0()) lastbit(s(s(x))) -> lastbit(x) zero(0()) -> true() zero(s(x)) -> false() - Signature: {conv/1,conviter/2,half/1,if/3,lastbit/1,zero/1,conv#/1,conviter#/2,half#/1,if#/3,lastbit#/1,zero#/1} / {0/0 ,cons/2,false/0,nil/0,s/1,true/0,c_1/1,c_2/1,c_3/0,c_4/0,c_5/1,c_6/3,c_7/0,c_8/0,c_9/0,c_10/1,c_11/0,c_12/0} - Obligation: innermost runtime complexity wrt. defined symbols {conv#,conviter#,half#,if#,lastbit# ,zero#} and constructors {0,cons,false,nil,s,true} + Applied Processor: RemoveHeads + Details: Consider the dependency graph 1:S:conv#(x) -> c_1(conviter#(x,cons(0(),nil()))) -->_1 conviter#(x,l) -> c_2(if#(zero(x),x,l)):2 2:S:conviter#(x,l) -> c_2(if#(zero(x),x,l)) -->_1 if#(false(),x,l) -> c_6(conviter#(half(x),cons(lastbit(x),l)),half#(x),lastbit#(x)):4 3:S:half#(s(s(x))) -> c_5(half#(x)) -->_1 half#(s(s(x))) -> c_5(half#(x)):3 4:S:if#(false(),x,l) -> c_6(conviter#(half(x),cons(lastbit(x),l)),half#(x),lastbit#(x)) -->_3 lastbit#(s(s(x))) -> c_10(lastbit#(x)):5 -->_2 half#(s(s(x))) -> c_5(half#(x)):3 -->_1 conviter#(x,l) -> c_2(if#(zero(x),x,l)):2 5:S:lastbit#(s(s(x))) -> c_10(lastbit#(x)) -->_1 lastbit#(s(s(x))) -> c_10(lastbit#(x)):5 Following roots of the dependency graph are removed, as the considered set of starting terms is closed under reduction with respect to these rules (modulo compound contexts). [(1,conv#(x) -> c_1(conviter#(x,cons(0(),nil()))))] * Step 7: Failure MAYBE + Considered Problem: - Strict DPs: conviter#(x,l) -> c_2(if#(zero(x),x,l)) half#(s(s(x))) -> c_5(half#(x)) if#(false(),x,l) -> c_6(conviter#(half(x),cons(lastbit(x),l)),half#(x),lastbit#(x)) lastbit#(s(s(x))) -> c_10(lastbit#(x)) - Weak TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) lastbit(0()) -> 0() lastbit(s(0())) -> s(0()) lastbit(s(s(x))) -> lastbit(x) zero(0()) -> true() zero(s(x)) -> false() - Signature: {conv/1,conviter/2,half/1,if/3,lastbit/1,zero/1,conv#/1,conviter#/2,half#/1,if#/3,lastbit#/1,zero#/1} / {0/0 ,cons/2,false/0,nil/0,s/1,true/0,c_1/1,c_2/1,c_3/0,c_4/0,c_5/1,c_6/3,c_7/0,c_8/0,c_9/0,c_10/1,c_11/0,c_12/0} - Obligation: innermost runtime complexity wrt. defined symbols {conv#,conviter#,half#,if#,lastbit# ,zero#} and constructors {0,cons,false,nil,s,true} + Applied Processor: EmptyProcessor + Details: The problem is still open. MAYBE