MAYBE * Step 1: DependencyPairs MAYBE + Considered Problem: - Strict TRS: cond1(true(),x) -> cond2(even(x),x) cond2(false(),x) -> cond1(neq(x,0()),p(x)) cond2(true(),x) -> cond1(neq(x,0()),div2(x)) div2(0()) -> 0() div2(s(0())) -> 0() div2(s(s(x))) -> s(div2(x)) even(0()) -> true() even(s(0())) -> false() even(s(s(x))) -> even(x) neq(0(),0()) -> false() neq(0(),s(x)) -> true() neq(s(x),0()) -> true() neq(s(x),s(y())) -> neq(x,y()) p(0()) -> 0() p(s(x)) -> x - Signature: {cond1/2,cond2/2,div2/1,even/1,neq/2,p/1} / {0/0,false/0,s/1,true/0,y/0} - Obligation: innermost runtime complexity wrt. defined symbols {cond1,cond2,div2,even,neq,p} and constructors {0,false,s ,true,y} + Applied Processor: DependencyPairs {dpKind_ = DT} + Details: We add the following dependency tuples: Strict DPs cond1#(true(),x) -> c_1(cond2#(even(x),x),even#(x)) cond2#(false(),x) -> c_2(cond1#(neq(x,0()),p(x)),neq#(x,0()),p#(x)) cond2#(true(),x) -> c_3(cond1#(neq(x,0()),div2(x)),neq#(x,0()),div2#(x)) div2#(0()) -> c_4() div2#(s(0())) -> c_5() div2#(s(s(x))) -> c_6(div2#(x)) even#(0()) -> c_7() even#(s(0())) -> c_8() even#(s(s(x))) -> c_9(even#(x)) neq#(0(),0()) -> c_10() neq#(0(),s(x)) -> c_11() neq#(s(x),0()) -> c_12() neq#(s(x),s(y())) -> c_13(neq#(x,y())) p#(0()) -> c_14() p#(s(x)) -> c_15() Weak DPs and mark the set of starting terms. * Step 2: UsableRules MAYBE + Considered Problem: - Strict DPs: cond1#(true(),x) -> c_1(cond2#(even(x),x),even#(x)) cond2#(false(),x) -> c_2(cond1#(neq(x,0()),p(x)),neq#(x,0()),p#(x)) cond2#(true(),x) -> c_3(cond1#(neq(x,0()),div2(x)),neq#(x,0()),div2#(x)) div2#(0()) -> c_4() div2#(s(0())) -> c_5() div2#(s(s(x))) -> c_6(div2#(x)) even#(0()) -> c_7() even#(s(0())) -> c_8() even#(s(s(x))) -> c_9(even#(x)) neq#(0(),0()) -> c_10() neq#(0(),s(x)) -> c_11() neq#(s(x),0()) -> c_12() neq#(s(x),s(y())) -> c_13(neq#(x,y())) p#(0()) -> c_14() p#(s(x)) -> c_15() - Weak TRS: cond1(true(),x) -> cond2(even(x),x) cond2(false(),x) -> cond1(neq(x,0()),p(x)) cond2(true(),x) -> cond1(neq(x,0()),div2(x)) div2(0()) -> 0() div2(s(0())) -> 0() div2(s(s(x))) -> s(div2(x)) even(0()) -> true() even(s(0())) -> false() even(s(s(x))) -> even(x) neq(0(),0()) -> false() neq(0(),s(x)) -> true() neq(s(x),0()) -> true() neq(s(x),s(y())) -> neq(x,y()) p(0()) -> 0() p(s(x)) -> x - Signature: {cond1/2,cond2/2,div2/1,even/1,neq/2,p/1,cond1#/2,cond2#/2,div2#/1,even#/1,neq#/2,p#/1} / {0/0,false/0,s/1 ,true/0,y/0,c_1/2,c_2/3,c_3/3,c_4/0,c_5/0,c_6/1,c_7/0,c_8/0,c_9/1,c_10/0,c_11/0,c_12/0,c_13/1,c_14/0,c_15/0} - Obligation: innermost runtime complexity wrt. defined symbols {cond1#,cond2#,div2#,even#,neq#,p#} and constructors {0 ,false,s,true,y} + Applied Processor: UsableRules + Details: We replace rewrite rules by usable rules: div2(0()) -> 0() div2(s(0())) -> 0() div2(s(s(x))) -> s(div2(x)) even(0()) -> true() even(s(0())) -> false() even(s(s(x))) -> even(x) neq(0(),0()) -> false() neq(s(x),0()) -> true() p(0()) -> 0() p(s(x)) -> x cond1#(true(),x) -> c_1(cond2#(even(x),x),even#(x)) cond2#(false(),x) -> c_2(cond1#(neq(x,0()),p(x)),neq#(x,0()),p#(x)) cond2#(true(),x) -> c_3(cond1#(neq(x,0()),div2(x)),neq#(x,0()),div2#(x)) div2#(0()) -> c_4() div2#(s(0())) -> c_5() div2#(s(s(x))) -> c_6(div2#(x)) even#(0()) -> c_7() even#(s(0())) -> c_8() even#(s(s(x))) -> c_9(even#(x)) neq#(0(),0()) -> c_10() neq#(0(),s(x)) -> c_11() neq#(s(x),0()) -> c_12() neq#(s(x),s(y())) -> c_13(neq#(x,y())) p#(0()) -> c_14() p#(s(x)) -> c_15() * Step 3: PredecessorEstimation MAYBE + Considered Problem: - Strict DPs: cond1#(true(),x) -> c_1(cond2#(even(x),x),even#(x)) cond2#(false(),x) -> c_2(cond1#(neq(x,0()),p(x)),neq#(x,0()),p#(x)) cond2#(true(),x) -> c_3(cond1#(neq(x,0()),div2(x)),neq#(x,0()),div2#(x)) div2#(0()) -> c_4() div2#(s(0())) -> c_5() div2#(s(s(x))) -> c_6(div2#(x)) even#(0()) -> c_7() even#(s(0())) -> c_8() even#(s(s(x))) -> c_9(even#(x)) neq#(0(),0()) -> c_10() neq#(0(),s(x)) -> c_11() neq#(s(x),0()) -> c_12() neq#(s(x),s(y())) -> c_13(neq#(x,y())) p#(0()) -> c_14() p#(s(x)) -> c_15() - Weak TRS: div2(0()) -> 0() div2(s(0())) -> 0() div2(s(s(x))) -> s(div2(x)) even(0()) -> true() even(s(0())) -> false() even(s(s(x))) -> even(x) neq(0(),0()) -> false() neq(s(x),0()) -> true() p(0()) -> 0() p(s(x)) -> x - Signature: {cond1/2,cond2/2,div2/1,even/1,neq/2,p/1,cond1#/2,cond2#/2,div2#/1,even#/1,neq#/2,p#/1} / {0/0,false/0,s/1 ,true/0,y/0,c_1/2,c_2/3,c_3/3,c_4/0,c_5/0,c_6/1,c_7/0,c_8/0,c_9/1,c_10/0,c_11/0,c_12/0,c_13/1,c_14/0,c_15/0} - Obligation: innermost runtime complexity wrt. defined symbols {cond1#,cond2#,div2#,even#,neq#,p#} and constructors {0 ,false,s,true,y} + Applied Processor: PredecessorEstimation {onSelection = all simple predecessor estimation selector} + Details: We estimate the number of application of {4,5,7,8,10,11,12,13,14,15} by application of Pre({4,5,7,8,10,11,12,13,14,15}) = {1,2,3,6,9}. Here rules are labelled as follows: 1: cond1#(true(),x) -> c_1(cond2#(even(x),x),even#(x)) 2: cond2#(false(),x) -> c_2(cond1#(neq(x,0()),p(x)),neq#(x,0()),p#(x)) 3: cond2#(true(),x) -> c_3(cond1#(neq(x,0()),div2(x)),neq#(x,0()),div2#(x)) 4: div2#(0()) -> c_4() 5: div2#(s(0())) -> c_5() 6: div2#(s(s(x))) -> c_6(div2#(x)) 7: even#(0()) -> c_7() 8: even#(s(0())) -> c_8() 9: even#(s(s(x))) -> c_9(even#(x)) 10: neq#(0(),0()) -> c_10() 11: neq#(0(),s(x)) -> c_11() 12: neq#(s(x),0()) -> c_12() 13: neq#(s(x),s(y())) -> c_13(neq#(x,y())) 14: p#(0()) -> c_14() 15: p#(s(x)) -> c_15() * Step 4: RemoveWeakSuffixes MAYBE + Considered Problem: - Strict DPs: cond1#(true(),x) -> c_1(cond2#(even(x),x),even#(x)) cond2#(false(),x) -> c_2(cond1#(neq(x,0()),p(x)),neq#(x,0()),p#(x)) cond2#(true(),x) -> c_3(cond1#(neq(x,0()),div2(x)),neq#(x,0()),div2#(x)) div2#(s(s(x))) -> c_6(div2#(x)) even#(s(s(x))) -> c_9(even#(x)) - Weak DPs: div2#(0()) -> c_4() div2#(s(0())) -> c_5() even#(0()) -> c_7() even#(s(0())) -> c_8() neq#(0(),0()) -> c_10() neq#(0(),s(x)) -> c_11() neq#(s(x),0()) -> c_12() neq#(s(x),s(y())) -> c_13(neq#(x,y())) p#(0()) -> c_14() p#(s(x)) -> c_15() - Weak TRS: div2(0()) -> 0() div2(s(0())) -> 0() div2(s(s(x))) -> s(div2(x)) even(0()) -> true() even(s(0())) -> false() even(s(s(x))) -> even(x) neq(0(),0()) -> false() neq(s(x),0()) -> true() p(0()) -> 0() p(s(x)) -> x - Signature: {cond1/2,cond2/2,div2/1,even/1,neq/2,p/1,cond1#/2,cond2#/2,div2#/1,even#/1,neq#/2,p#/1} / {0/0,false/0,s/1 ,true/0,y/0,c_1/2,c_2/3,c_3/3,c_4/0,c_5/0,c_6/1,c_7/0,c_8/0,c_9/1,c_10/0,c_11/0,c_12/0,c_13/1,c_14/0,c_15/0} - Obligation: innermost runtime complexity wrt. defined symbols {cond1#,cond2#,div2#,even#,neq#,p#} and constructors {0 ,false,s,true,y} + Applied Processor: RemoveWeakSuffixes + Details: Consider the dependency graph 1:S:cond1#(true(),x) -> c_1(cond2#(even(x),x),even#(x)) -->_2 even#(s(s(x))) -> c_9(even#(x)):5 -->_1 cond2#(true(),x) -> c_3(cond1#(neq(x,0()),div2(x)),neq#(x,0()),div2#(x)):3 -->_1 cond2#(false(),x) -> c_2(cond1#(neq(x,0()),p(x)),neq#(x,0()),p#(x)):2 -->_2 even#(s(0())) -> c_8():9 -->_2 even#(0()) -> c_7():8 2:S:cond2#(false(),x) -> c_2(cond1#(neq(x,0()),p(x)),neq#(x,0()),p#(x)) -->_3 p#(s(x)) -> c_15():15 -->_3 p#(0()) -> c_14():14 -->_2 neq#(s(x),0()) -> c_12():12 -->_2 neq#(0(),0()) -> c_10():10 -->_1 cond1#(true(),x) -> c_1(cond2#(even(x),x),even#(x)):1 3:S:cond2#(true(),x) -> c_3(cond1#(neq(x,0()),div2(x)),neq#(x,0()),div2#(x)) -->_3 div2#(s(s(x))) -> c_6(div2#(x)):4 -->_2 neq#(s(x),0()) -> c_12():12 -->_2 neq#(0(),0()) -> c_10():10 -->_3 div2#(s(0())) -> c_5():7 -->_3 div2#(0()) -> c_4():6 -->_1 cond1#(true(),x) -> c_1(cond2#(even(x),x),even#(x)):1 4:S:div2#(s(s(x))) -> c_6(div2#(x)) -->_1 div2#(s(0())) -> c_5():7 -->_1 div2#(0()) -> c_4():6 -->_1 div2#(s(s(x))) -> c_6(div2#(x)):4 5:S:even#(s(s(x))) -> c_9(even#(x)) -->_1 even#(s(0())) -> c_8():9 -->_1 even#(0()) -> c_7():8 -->_1 even#(s(s(x))) -> c_9(even#(x)):5 6:W:div2#(0()) -> c_4() 7:W:div2#(s(0())) -> c_5() 8:W:even#(0()) -> c_7() 9:W:even#(s(0())) -> c_8() 10:W:neq#(0(),0()) -> c_10() 11:W:neq#(0(),s(x)) -> c_11() 12:W:neq#(s(x),0()) -> c_12() 13:W:neq#(s(x),s(y())) -> c_13(neq#(x,y())) 14:W:p#(0()) -> c_14() 15:W:p#(s(x)) -> c_15() The following weak DPs constitute a sub-graph of the DG that is closed under successors. The DPs are removed. 13: neq#(s(x),s(y())) -> c_13(neq#(x,y())) 11: neq#(0(),s(x)) -> c_11() 14: p#(0()) -> c_14() 15: p#(s(x)) -> c_15() 10: neq#(0(),0()) -> c_10() 12: neq#(s(x),0()) -> c_12() 6: div2#(0()) -> c_4() 7: div2#(s(0())) -> c_5() 8: even#(0()) -> c_7() 9: even#(s(0())) -> c_8() * Step 5: SimplifyRHS MAYBE + Considered Problem: - Strict DPs: cond1#(true(),x) -> c_1(cond2#(even(x),x),even#(x)) cond2#(false(),x) -> c_2(cond1#(neq(x,0()),p(x)),neq#(x,0()),p#(x)) cond2#(true(),x) -> c_3(cond1#(neq(x,0()),div2(x)),neq#(x,0()),div2#(x)) div2#(s(s(x))) -> c_6(div2#(x)) even#(s(s(x))) -> c_9(even#(x)) - Weak TRS: div2(0()) -> 0() div2(s(0())) -> 0() div2(s(s(x))) -> s(div2(x)) even(0()) -> true() even(s(0())) -> false() even(s(s(x))) -> even(x) neq(0(),0()) -> false() neq(s(x),0()) -> true() p(0()) -> 0() p(s(x)) -> x - Signature: {cond1/2,cond2/2,div2/1,even/1,neq/2,p/1,cond1#/2,cond2#/2,div2#/1,even#/1,neq#/2,p#/1} / {0/0,false/0,s/1 ,true/0,y/0,c_1/2,c_2/3,c_3/3,c_4/0,c_5/0,c_6/1,c_7/0,c_8/0,c_9/1,c_10/0,c_11/0,c_12/0,c_13/1,c_14/0,c_15/0} - Obligation: innermost runtime complexity wrt. defined symbols {cond1#,cond2#,div2#,even#,neq#,p#} and constructors {0 ,false,s,true,y} + Applied Processor: SimplifyRHS + Details: Consider the dependency graph 1:S:cond1#(true(),x) -> c_1(cond2#(even(x),x),even#(x)) -->_2 even#(s(s(x))) -> c_9(even#(x)):5 -->_1 cond2#(true(),x) -> c_3(cond1#(neq(x,0()),div2(x)),neq#(x,0()),div2#(x)):3 -->_1 cond2#(false(),x) -> c_2(cond1#(neq(x,0()),p(x)),neq#(x,0()),p#(x)):2 2:S:cond2#(false(),x) -> c_2(cond1#(neq(x,0()),p(x)),neq#(x,0()),p#(x)) -->_1 cond1#(true(),x) -> c_1(cond2#(even(x),x),even#(x)):1 3:S:cond2#(true(),x) -> c_3(cond1#(neq(x,0()),div2(x)),neq#(x,0()),div2#(x)) -->_3 div2#(s(s(x))) -> c_6(div2#(x)):4 -->_1 cond1#(true(),x) -> c_1(cond2#(even(x),x),even#(x)):1 4:S:div2#(s(s(x))) -> c_6(div2#(x)) -->_1 div2#(s(s(x))) -> c_6(div2#(x)):4 5:S:even#(s(s(x))) -> c_9(even#(x)) -->_1 even#(s(s(x))) -> c_9(even#(x)):5 Due to missing edges in the depndency graph, the right-hand sides of following rules could be simplified: cond2#(false(),x) -> c_2(cond1#(neq(x,0()),p(x))) cond2#(true(),x) -> c_3(cond1#(neq(x,0()),div2(x)),div2#(x)) * Step 6: Failure MAYBE + Considered Problem: - Strict DPs: cond1#(true(),x) -> c_1(cond2#(even(x),x),even#(x)) cond2#(false(),x) -> c_2(cond1#(neq(x,0()),p(x))) cond2#(true(),x) -> c_3(cond1#(neq(x,0()),div2(x)),div2#(x)) div2#(s(s(x))) -> c_6(div2#(x)) even#(s(s(x))) -> c_9(even#(x)) - Weak TRS: div2(0()) -> 0() div2(s(0())) -> 0() div2(s(s(x))) -> s(div2(x)) even(0()) -> true() even(s(0())) -> false() even(s(s(x))) -> even(x) neq(0(),0()) -> false() neq(s(x),0()) -> true() p(0()) -> 0() p(s(x)) -> x - Signature: {cond1/2,cond2/2,div2/1,even/1,neq/2,p/1,cond1#/2,cond2#/2,div2#/1,even#/1,neq#/2,p#/1} / {0/0,false/0,s/1 ,true/0,y/0,c_1/2,c_2/1,c_3/2,c_4/0,c_5/0,c_6/1,c_7/0,c_8/0,c_9/1,c_10/0,c_11/0,c_12/0,c_13/1,c_14/0,c_15/0} - Obligation: innermost runtime complexity wrt. defined symbols {cond1#,cond2#,div2#,even#,neq#,p#} and constructors {0 ,false,s,true,y} + Applied Processor: EmptyProcessor + Details: The problem is still open. MAYBE