MAYBE * Step 1: DependencyPairs MAYBE + Considered Problem: - Strict TRS: bitIter(x,y) -> if(zero(x),x,inc(y)) bits(x) -> bitIter(x,0()) half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) if(false(),x,y) -> bitIter(half(x),y) if(true(),x,y) -> p(y) inc(0()) -> 0() inc(s(x)) -> s(inc(x)) p(0()) -> 0() p(s(x)) -> x zero(0()) -> true() zero(s(x)) -> false() - Signature: {bitIter/2,bits/1,half/1,if/3,inc/1,p/1,zero/1} / {0/0,false/0,s/1,true/0} - Obligation: innermost runtime complexity wrt. defined symbols {bitIter,bits,half,if,inc,p,zero} and constructors {0 ,false,s,true} + Applied Processor: DependencyPairs {dpKind_ = DT} + Details: We add the following dependency tuples: Strict DPs bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),zero#(x),inc#(y)) bits#(x) -> c_2(bitIter#(x,0())) half#(0()) -> c_3() half#(s(0())) -> c_4() half#(s(s(x))) -> c_5(half#(x)) if#(false(),x,y) -> c_6(bitIter#(half(x),y),half#(x)) if#(true(),x,y) -> c_7(p#(y)) inc#(0()) -> c_8() inc#(s(x)) -> c_9(inc#(x)) p#(0()) -> c_10() p#(s(x)) -> c_11() zero#(0()) -> c_12() zero#(s(x)) -> c_13() Weak DPs and mark the set of starting terms. * Step 2: UsableRules MAYBE + Considered Problem: - Strict DPs: bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),zero#(x),inc#(y)) bits#(x) -> c_2(bitIter#(x,0())) half#(0()) -> c_3() half#(s(0())) -> c_4() half#(s(s(x))) -> c_5(half#(x)) if#(false(),x,y) -> c_6(bitIter#(half(x),y),half#(x)) if#(true(),x,y) -> c_7(p#(y)) inc#(0()) -> c_8() inc#(s(x)) -> c_9(inc#(x)) p#(0()) -> c_10() p#(s(x)) -> c_11() zero#(0()) -> c_12() zero#(s(x)) -> c_13() - Weak TRS: bitIter(x,y) -> if(zero(x),x,inc(y)) bits(x) -> bitIter(x,0()) half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) if(false(),x,y) -> bitIter(half(x),y) if(true(),x,y) -> p(y) inc(0()) -> 0() inc(s(x)) -> s(inc(x)) p(0()) -> 0() p(s(x)) -> x zero(0()) -> true() zero(s(x)) -> false() - Signature: {bitIter/2,bits/1,half/1,if/3,inc/1,p/1,zero/1,bitIter#/2,bits#/1,half#/1,if#/3,inc#/1,p#/1,zero#/1} / {0/0 ,false/0,s/1,true/0,c_1/3,c_2/1,c_3/0,c_4/0,c_5/1,c_6/2,c_7/1,c_8/0,c_9/1,c_10/0,c_11/0,c_12/0,c_13/0} - Obligation: innermost runtime complexity wrt. defined symbols {bitIter#,bits#,half#,if#,inc#,p# ,zero#} and constructors {0,false,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)) inc(0()) -> 0() inc(s(x)) -> s(inc(x)) zero(0()) -> true() zero(s(x)) -> false() bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),zero#(x),inc#(y)) bits#(x) -> c_2(bitIter#(x,0())) half#(0()) -> c_3() half#(s(0())) -> c_4() half#(s(s(x))) -> c_5(half#(x)) if#(false(),x,y) -> c_6(bitIter#(half(x),y),half#(x)) if#(true(),x,y) -> c_7(p#(y)) inc#(0()) -> c_8() inc#(s(x)) -> c_9(inc#(x)) p#(0()) -> c_10() p#(s(x)) -> c_11() zero#(0()) -> c_12() zero#(s(x)) -> c_13() * Step 3: PredecessorEstimation MAYBE + Considered Problem: - Strict DPs: bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),zero#(x),inc#(y)) bits#(x) -> c_2(bitIter#(x,0())) half#(0()) -> c_3() half#(s(0())) -> c_4() half#(s(s(x))) -> c_5(half#(x)) if#(false(),x,y) -> c_6(bitIter#(half(x),y),half#(x)) if#(true(),x,y) -> c_7(p#(y)) inc#(0()) -> c_8() inc#(s(x)) -> c_9(inc#(x)) p#(0()) -> c_10() p#(s(x)) -> c_11() zero#(0()) -> c_12() zero#(s(x)) -> c_13() - Weak TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) inc(0()) -> 0() inc(s(x)) -> s(inc(x)) zero(0()) -> true() zero(s(x)) -> false() - Signature: {bitIter/2,bits/1,half/1,if/3,inc/1,p/1,zero/1,bitIter#/2,bits#/1,half#/1,if#/3,inc#/1,p#/1,zero#/1} / {0/0 ,false/0,s/1,true/0,c_1/3,c_2/1,c_3/0,c_4/0,c_5/1,c_6/2,c_7/1,c_8/0,c_9/1,c_10/0,c_11/0,c_12/0,c_13/0} - Obligation: innermost runtime complexity wrt. defined symbols {bitIter#,bits#,half#,if#,inc#,p# ,zero#} and constructors {0,false,s,true} + Applied Processor: PredecessorEstimation {onSelection = all simple predecessor estimation selector} + Details: We estimate the number of application of {3,4,8,10,11,12,13} by application of Pre({3,4,8,10,11,12,13}) = {1,5,6,7,9}. Here rules are labelled as follows: 1: bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),zero#(x),inc#(y)) 2: bits#(x) -> c_2(bitIter#(x,0())) 3: half#(0()) -> c_3() 4: half#(s(0())) -> c_4() 5: half#(s(s(x))) -> c_5(half#(x)) 6: if#(false(),x,y) -> c_6(bitIter#(half(x),y),half#(x)) 7: if#(true(),x,y) -> c_7(p#(y)) 8: inc#(0()) -> c_8() 9: inc#(s(x)) -> c_9(inc#(x)) 10: p#(0()) -> c_10() 11: p#(s(x)) -> c_11() 12: zero#(0()) -> c_12() 13: zero#(s(x)) -> c_13() * Step 4: PredecessorEstimation MAYBE + Considered Problem: - Strict DPs: bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),zero#(x),inc#(y)) bits#(x) -> c_2(bitIter#(x,0())) half#(s(s(x))) -> c_5(half#(x)) if#(false(),x,y) -> c_6(bitIter#(half(x),y),half#(x)) if#(true(),x,y) -> c_7(p#(y)) inc#(s(x)) -> c_9(inc#(x)) - Weak DPs: half#(0()) -> c_3() half#(s(0())) -> c_4() inc#(0()) -> c_8() p#(0()) -> c_10() p#(s(x)) -> c_11() zero#(0()) -> c_12() zero#(s(x)) -> c_13() - Weak TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) inc(0()) -> 0() inc(s(x)) -> s(inc(x)) zero(0()) -> true() zero(s(x)) -> false() - Signature: {bitIter/2,bits/1,half/1,if/3,inc/1,p/1,zero/1,bitIter#/2,bits#/1,half#/1,if#/3,inc#/1,p#/1,zero#/1} / {0/0 ,false/0,s/1,true/0,c_1/3,c_2/1,c_3/0,c_4/0,c_5/1,c_6/2,c_7/1,c_8/0,c_9/1,c_10/0,c_11/0,c_12/0,c_13/0} - Obligation: innermost runtime complexity wrt. defined symbols {bitIter#,bits#,half#,if#,inc#,p# ,zero#} and constructors {0,false,s,true} + Applied Processor: PredecessorEstimation {onSelection = all simple predecessor estimation selector} + Details: We estimate the number of application of {5} by application of Pre({5}) = {1}. Here rules are labelled as follows: 1: bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),zero#(x),inc#(y)) 2: bits#(x) -> c_2(bitIter#(x,0())) 3: half#(s(s(x))) -> c_5(half#(x)) 4: if#(false(),x,y) -> c_6(bitIter#(half(x),y),half#(x)) 5: if#(true(),x,y) -> c_7(p#(y)) 6: inc#(s(x)) -> c_9(inc#(x)) 7: half#(0()) -> c_3() 8: half#(s(0())) -> c_4() 9: inc#(0()) -> c_8() 10: p#(0()) -> c_10() 11: p#(s(x)) -> c_11() 12: zero#(0()) -> c_12() 13: zero#(s(x)) -> c_13() * Step 5: RemoveWeakSuffixes MAYBE + Considered Problem: - Strict DPs: bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),zero#(x),inc#(y)) bits#(x) -> c_2(bitIter#(x,0())) half#(s(s(x))) -> c_5(half#(x)) if#(false(),x,y) -> c_6(bitIter#(half(x),y),half#(x)) inc#(s(x)) -> c_9(inc#(x)) - Weak DPs: half#(0()) -> c_3() half#(s(0())) -> c_4() if#(true(),x,y) -> c_7(p#(y)) inc#(0()) -> c_8() p#(0()) -> c_10() p#(s(x)) -> c_11() zero#(0()) -> c_12() zero#(s(x)) -> c_13() - Weak TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) inc(0()) -> 0() inc(s(x)) -> s(inc(x)) zero(0()) -> true() zero(s(x)) -> false() - Signature: {bitIter/2,bits/1,half/1,if/3,inc/1,p/1,zero/1,bitIter#/2,bits#/1,half#/1,if#/3,inc#/1,p#/1,zero#/1} / {0/0 ,false/0,s/1,true/0,c_1/3,c_2/1,c_3/0,c_4/0,c_5/1,c_6/2,c_7/1,c_8/0,c_9/1,c_10/0,c_11/0,c_12/0,c_13/0} - Obligation: innermost runtime complexity wrt. defined symbols {bitIter#,bits#,half#,if#,inc#,p# ,zero#} and constructors {0,false,s,true} + Applied Processor: RemoveWeakSuffixes + Details: Consider the dependency graph 1:S:bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),zero#(x),inc#(y)) -->_1 if#(true(),x,y) -> c_7(p#(y)):8 -->_3 inc#(s(x)) -> c_9(inc#(x)):5 -->_1 if#(false(),x,y) -> c_6(bitIter#(half(x),y),half#(x)):4 -->_2 zero#(s(x)) -> c_13():13 -->_2 zero#(0()) -> c_12():12 -->_3 inc#(0()) -> c_8():9 2:S:bits#(x) -> c_2(bitIter#(x,0())) -->_1 bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),zero#(x),inc#(y)):1 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,y) -> c_6(bitIter#(half(x),y),half#(x)) -->_2 half#(s(0())) -> c_4():7 -->_2 half#(0()) -> c_3():6 -->_2 half#(s(s(x))) -> c_5(half#(x)):3 -->_1 bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),zero#(x),inc#(y)):1 5:S:inc#(s(x)) -> c_9(inc#(x)) -->_1 inc#(0()) -> c_8():9 -->_1 inc#(s(x)) -> c_9(inc#(x)):5 6:W:half#(0()) -> c_3() 7:W:half#(s(0())) -> c_4() 8:W:if#(true(),x,y) -> c_7(p#(y)) -->_1 p#(s(x)) -> c_11():11 -->_1 p#(0()) -> c_10():10 9:W:inc#(0()) -> c_8() 10:W:p#(0()) -> c_10() 11:W:p#(s(x)) -> c_11() 12:W:zero#(0()) -> c_12() 13:W:zero#(s(x)) -> c_13() The following weak DPs constitute a sub-graph of the DG that is closed under successors. The DPs are removed. 12: zero#(0()) -> c_12() 13: zero#(s(x)) -> c_13() 6: half#(0()) -> c_3() 7: half#(s(0())) -> c_4() 9: inc#(0()) -> c_8() 8: if#(true(),x,y) -> c_7(p#(y)) 10: p#(0()) -> c_10() 11: p#(s(x)) -> c_11() * Step 6: SimplifyRHS MAYBE + Considered Problem: - Strict DPs: bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),zero#(x),inc#(y)) bits#(x) -> c_2(bitIter#(x,0())) half#(s(s(x))) -> c_5(half#(x)) if#(false(),x,y) -> c_6(bitIter#(half(x),y),half#(x)) inc#(s(x)) -> c_9(inc#(x)) - Weak TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) inc(0()) -> 0() inc(s(x)) -> s(inc(x)) zero(0()) -> true() zero(s(x)) -> false() - Signature: {bitIter/2,bits/1,half/1,if/3,inc/1,p/1,zero/1,bitIter#/2,bits#/1,half#/1,if#/3,inc#/1,p#/1,zero#/1} / {0/0 ,false/0,s/1,true/0,c_1/3,c_2/1,c_3/0,c_4/0,c_5/1,c_6/2,c_7/1,c_8/0,c_9/1,c_10/0,c_11/0,c_12/0,c_13/0} - Obligation: innermost runtime complexity wrt. defined symbols {bitIter#,bits#,half#,if#,inc#,p# ,zero#} and constructors {0,false,s,true} + Applied Processor: SimplifyRHS + Details: Consider the dependency graph 1:S:bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),zero#(x),inc#(y)) -->_3 inc#(s(x)) -> c_9(inc#(x)):5 -->_1 if#(false(),x,y) -> c_6(bitIter#(half(x),y),half#(x)):4 2:S:bits#(x) -> c_2(bitIter#(x,0())) -->_1 bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),zero#(x),inc#(y)):1 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,y) -> c_6(bitIter#(half(x),y),half#(x)) -->_2 half#(s(s(x))) -> c_5(half#(x)):3 -->_1 bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),zero#(x),inc#(y)):1 5:S:inc#(s(x)) -> c_9(inc#(x)) -->_1 inc#(s(x)) -> c_9(inc#(x)):5 Due to missing edges in the depndency graph, the right-hand sides of following rules could be simplified: bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),inc#(y)) * Step 7: RemoveHeads MAYBE + Considered Problem: - Strict DPs: bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),inc#(y)) bits#(x) -> c_2(bitIter#(x,0())) half#(s(s(x))) -> c_5(half#(x)) if#(false(),x,y) -> c_6(bitIter#(half(x),y),half#(x)) inc#(s(x)) -> c_9(inc#(x)) - Weak TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) inc(0()) -> 0() inc(s(x)) -> s(inc(x)) zero(0()) -> true() zero(s(x)) -> false() - Signature: {bitIter/2,bits/1,half/1,if/3,inc/1,p/1,zero/1,bitIter#/2,bits#/1,half#/1,if#/3,inc#/1,p#/1,zero#/1} / {0/0 ,false/0,s/1,true/0,c_1/2,c_2/1,c_3/0,c_4/0,c_5/1,c_6/2,c_7/1,c_8/0,c_9/1,c_10/0,c_11/0,c_12/0,c_13/0} - Obligation: innermost runtime complexity wrt. defined symbols {bitIter#,bits#,half#,if#,inc#,p# ,zero#} and constructors {0,false,s,true} + Applied Processor: RemoveHeads + Details: Consider the dependency graph 1:S:bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),inc#(y)) -->_2 inc#(s(x)) -> c_9(inc#(x)):5 -->_1 if#(false(),x,y) -> c_6(bitIter#(half(x),y),half#(x)):4 2:S:bits#(x) -> c_2(bitIter#(x,0())) -->_1 bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),inc#(y)):1 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,y) -> c_6(bitIter#(half(x),y),half#(x)) -->_2 half#(s(s(x))) -> c_5(half#(x)):3 -->_1 bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),inc#(y)):1 5:S:inc#(s(x)) -> c_9(inc#(x)) -->_1 inc#(s(x)) -> c_9(inc#(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). [(2,bits#(x) -> c_2(bitIter#(x,0())))] * Step 8: Failure MAYBE + Considered Problem: - Strict DPs: bitIter#(x,y) -> c_1(if#(zero(x),x,inc(y)),inc#(y)) half#(s(s(x))) -> c_5(half#(x)) if#(false(),x,y) -> c_6(bitIter#(half(x),y),half#(x)) inc#(s(x)) -> c_9(inc#(x)) - Weak TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) inc(0()) -> 0() inc(s(x)) -> s(inc(x)) zero(0()) -> true() zero(s(x)) -> false() - Signature: {bitIter/2,bits/1,half/1,if/3,inc/1,p/1,zero/1,bitIter#/2,bits#/1,half#/1,if#/3,inc#/1,p#/1,zero#/1} / {0/0 ,false/0,s/1,true/0,c_1/2,c_2/1,c_3/0,c_4/0,c_5/1,c_6/2,c_7/1,c_8/0,c_9/1,c_10/0,c_11/0,c_12/0,c_13/0} - Obligation: innermost runtime complexity wrt. defined symbols {bitIter#,bits#,half#,if#,inc#,p# ,zero#} and constructors {0,false,s,true} + Applied Processor: EmptyProcessor + Details: The problem is still open. MAYBE