MAYBE * Step 1: DependencyPairs MAYBE + Considered Problem: - Strict TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) help(x,y) -> ifb(lt(y,x),x,y) ifa(false(),x) -> logZeroError() ifa(true(),x) -> help(x,1()) ifb(false(),x,y) -> y ifb(true(),x,y) -> help(half(x),s(y)) logarithm(x) -> ifa(lt(0(),x),x) lt(x,0()) -> false() lt(0(),s(x)) -> true() lt(s(x),s(y)) -> lt(x,y) - Signature: {half/1,help/2,ifa/2,ifb/3,logarithm/1,lt/2} / {0/0,1/0,false/0,logZeroError/0,s/1,true/0} - Obligation: innermost runtime complexity wrt. defined symbols {half,help,ifa,ifb,logarithm,lt} and constructors {0,1 ,false,logZeroError,s,true} + Applied Processor: DependencyPairs {dpKind_ = DT} + Details: We add the following dependency tuples: Strict DPs half#(0()) -> c_1() half#(s(0())) -> c_2() half#(s(s(x))) -> c_3(half#(x)) help#(x,y) -> c_4(ifb#(lt(y,x),x,y),lt#(y,x)) ifa#(false(),x) -> c_5() ifa#(true(),x) -> c_6(help#(x,1())) ifb#(false(),x,y) -> c_7() ifb#(true(),x,y) -> c_8(help#(half(x),s(y)),half#(x)) logarithm#(x) -> c_9(ifa#(lt(0(),x),x),lt#(0(),x)) lt#(x,0()) -> c_10() lt#(0(),s(x)) -> c_11() lt#(s(x),s(y)) -> c_12(lt#(x,y)) Weak DPs and mark the set of starting terms. * Step 2: UsableRules MAYBE + Considered Problem: - Strict DPs: half#(0()) -> c_1() half#(s(0())) -> c_2() half#(s(s(x))) -> c_3(half#(x)) help#(x,y) -> c_4(ifb#(lt(y,x),x,y),lt#(y,x)) ifa#(false(),x) -> c_5() ifa#(true(),x) -> c_6(help#(x,1())) ifb#(false(),x,y) -> c_7() ifb#(true(),x,y) -> c_8(help#(half(x),s(y)),half#(x)) logarithm#(x) -> c_9(ifa#(lt(0(),x),x),lt#(0(),x)) lt#(x,0()) -> c_10() lt#(0(),s(x)) -> c_11() lt#(s(x),s(y)) -> c_12(lt#(x,y)) - Weak TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) help(x,y) -> ifb(lt(y,x),x,y) ifa(false(),x) -> logZeroError() ifa(true(),x) -> help(x,1()) ifb(false(),x,y) -> y ifb(true(),x,y) -> help(half(x),s(y)) logarithm(x) -> ifa(lt(0(),x),x) lt(x,0()) -> false() lt(0(),s(x)) -> true() lt(s(x),s(y)) -> lt(x,y) - Signature: {half/1,help/2,ifa/2,ifb/3,logarithm/1,lt/2,half#/1,help#/2,ifa#/2,ifb#/3,logarithm#/1,lt#/2} / {0/0,1/0 ,false/0,logZeroError/0,s/1,true/0,c_1/0,c_2/0,c_3/1,c_4/2,c_5/0,c_6/1,c_7/0,c_8/2,c_9/2,c_10/0,c_11/0 ,c_12/1} - Obligation: innermost runtime complexity wrt. defined symbols {half#,help#,ifa#,ifb#,logarithm#,lt#} and constructors {0 ,1,false,logZeroError,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)) lt(x,0()) -> false() lt(0(),s(x)) -> true() lt(s(x),s(y)) -> lt(x,y) half#(0()) -> c_1() half#(s(0())) -> c_2() half#(s(s(x))) -> c_3(half#(x)) help#(x,y) -> c_4(ifb#(lt(y,x),x,y),lt#(y,x)) ifa#(false(),x) -> c_5() ifa#(true(),x) -> c_6(help#(x,1())) ifb#(false(),x,y) -> c_7() ifb#(true(),x,y) -> c_8(help#(half(x),s(y)),half#(x)) logarithm#(x) -> c_9(ifa#(lt(0(),x),x),lt#(0(),x)) lt#(x,0()) -> c_10() lt#(0(),s(x)) -> c_11() lt#(s(x),s(y)) -> c_12(lt#(x,y)) * Step 3: PredecessorEstimation MAYBE + Considered Problem: - Strict DPs: half#(0()) -> c_1() half#(s(0())) -> c_2() half#(s(s(x))) -> c_3(half#(x)) help#(x,y) -> c_4(ifb#(lt(y,x),x,y),lt#(y,x)) ifa#(false(),x) -> c_5() ifa#(true(),x) -> c_6(help#(x,1())) ifb#(false(),x,y) -> c_7() ifb#(true(),x,y) -> c_8(help#(half(x),s(y)),half#(x)) logarithm#(x) -> c_9(ifa#(lt(0(),x),x),lt#(0(),x)) lt#(x,0()) -> c_10() lt#(0(),s(x)) -> c_11() lt#(s(x),s(y)) -> c_12(lt#(x,y)) - Weak TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) lt(x,0()) -> false() lt(0(),s(x)) -> true() lt(s(x),s(y)) -> lt(x,y) - Signature: {half/1,help/2,ifa/2,ifb/3,logarithm/1,lt/2,half#/1,help#/2,ifa#/2,ifb#/3,logarithm#/1,lt#/2} / {0/0,1/0 ,false/0,logZeroError/0,s/1,true/0,c_1/0,c_2/0,c_3/1,c_4/2,c_5/0,c_6/1,c_7/0,c_8/2,c_9/2,c_10/0,c_11/0 ,c_12/1} - Obligation: innermost runtime complexity wrt. defined symbols {half#,help#,ifa#,ifb#,logarithm#,lt#} and constructors {0 ,1,false,logZeroError,s,true} + Applied Processor: PredecessorEstimation {onSelection = all simple predecessor estimation selector} + Details: We estimate the number of application of {1,2,5,7,10,11} by application of Pre({1,2,5,7,10,11}) = {3,4,8,9,12}. Here rules are labelled as follows: 1: half#(0()) -> c_1() 2: half#(s(0())) -> c_2() 3: half#(s(s(x))) -> c_3(half#(x)) 4: help#(x,y) -> c_4(ifb#(lt(y,x),x,y),lt#(y,x)) 5: ifa#(false(),x) -> c_5() 6: ifa#(true(),x) -> c_6(help#(x,1())) 7: ifb#(false(),x,y) -> c_7() 8: ifb#(true(),x,y) -> c_8(help#(half(x),s(y)),half#(x)) 9: logarithm#(x) -> c_9(ifa#(lt(0(),x),x),lt#(0(),x)) 10: lt#(x,0()) -> c_10() 11: lt#(0(),s(x)) -> c_11() 12: lt#(s(x),s(y)) -> c_12(lt#(x,y)) * Step 4: RemoveWeakSuffixes MAYBE + Considered Problem: - Strict DPs: half#(s(s(x))) -> c_3(half#(x)) help#(x,y) -> c_4(ifb#(lt(y,x),x,y),lt#(y,x)) ifa#(true(),x) -> c_6(help#(x,1())) ifb#(true(),x,y) -> c_8(help#(half(x),s(y)),half#(x)) logarithm#(x) -> c_9(ifa#(lt(0(),x),x),lt#(0(),x)) lt#(s(x),s(y)) -> c_12(lt#(x,y)) - Weak DPs: half#(0()) -> c_1() half#(s(0())) -> c_2() ifa#(false(),x) -> c_5() ifb#(false(),x,y) -> c_7() lt#(x,0()) -> c_10() lt#(0(),s(x)) -> c_11() - Weak TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) lt(x,0()) -> false() lt(0(),s(x)) -> true() lt(s(x),s(y)) -> lt(x,y) - Signature: {half/1,help/2,ifa/2,ifb/3,logarithm/1,lt/2,half#/1,help#/2,ifa#/2,ifb#/3,logarithm#/1,lt#/2} / {0/0,1/0 ,false/0,logZeroError/0,s/1,true/0,c_1/0,c_2/0,c_3/1,c_4/2,c_5/0,c_6/1,c_7/0,c_8/2,c_9/2,c_10/0,c_11/0 ,c_12/1} - Obligation: innermost runtime complexity wrt. defined symbols {half#,help#,ifa#,ifb#,logarithm#,lt#} and constructors {0 ,1,false,logZeroError,s,true} + Applied Processor: RemoveWeakSuffixes + Details: Consider the dependency graph 1:S:half#(s(s(x))) -> c_3(half#(x)) -->_1 half#(s(0())) -> c_2():8 -->_1 half#(0()) -> c_1():7 -->_1 half#(s(s(x))) -> c_3(half#(x)):1 2:S:help#(x,y) -> c_4(ifb#(lt(y,x),x,y),lt#(y,x)) -->_2 lt#(s(x),s(y)) -> c_12(lt#(x,y)):6 -->_1 ifb#(true(),x,y) -> c_8(help#(half(x),s(y)),half#(x)):4 -->_2 lt#(0(),s(x)) -> c_11():12 -->_2 lt#(x,0()) -> c_10():11 -->_1 ifb#(false(),x,y) -> c_7():10 3:S:ifa#(true(),x) -> c_6(help#(x,1())) -->_1 help#(x,y) -> c_4(ifb#(lt(y,x),x,y),lt#(y,x)):2 4:S:ifb#(true(),x,y) -> c_8(help#(half(x),s(y)),half#(x)) -->_2 half#(s(0())) -> c_2():8 -->_2 half#(0()) -> c_1():7 -->_1 help#(x,y) -> c_4(ifb#(lt(y,x),x,y),lt#(y,x)):2 -->_2 half#(s(s(x))) -> c_3(half#(x)):1 5:S:logarithm#(x) -> c_9(ifa#(lt(0(),x),x),lt#(0(),x)) -->_2 lt#(0(),s(x)) -> c_11():12 -->_2 lt#(x,0()) -> c_10():11 -->_1 ifa#(false(),x) -> c_5():9 -->_1 ifa#(true(),x) -> c_6(help#(x,1())):3 6:S:lt#(s(x),s(y)) -> c_12(lt#(x,y)) -->_1 lt#(0(),s(x)) -> c_11():12 -->_1 lt#(x,0()) -> c_10():11 -->_1 lt#(s(x),s(y)) -> c_12(lt#(x,y)):6 7:W:half#(0()) -> c_1() 8:W:half#(s(0())) -> c_2() 9:W:ifa#(false(),x) -> c_5() 10:W:ifb#(false(),x,y) -> c_7() 11:W:lt#(x,0()) -> c_10() 12:W:lt#(0(),s(x)) -> c_11() The following weak DPs constitute a sub-graph of the DG that is closed under successors. The DPs are removed. 9: ifa#(false(),x) -> c_5() 10: ifb#(false(),x,y) -> c_7() 11: lt#(x,0()) -> c_10() 12: lt#(0(),s(x)) -> c_11() 7: half#(0()) -> c_1() 8: half#(s(0())) -> c_2() * Step 5: SimplifyRHS MAYBE + Considered Problem: - Strict DPs: half#(s(s(x))) -> c_3(half#(x)) help#(x,y) -> c_4(ifb#(lt(y,x),x,y),lt#(y,x)) ifa#(true(),x) -> c_6(help#(x,1())) ifb#(true(),x,y) -> c_8(help#(half(x),s(y)),half#(x)) logarithm#(x) -> c_9(ifa#(lt(0(),x),x),lt#(0(),x)) lt#(s(x),s(y)) -> c_12(lt#(x,y)) - Weak TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) lt(x,0()) -> false() lt(0(),s(x)) -> true() lt(s(x),s(y)) -> lt(x,y) - Signature: {half/1,help/2,ifa/2,ifb/3,logarithm/1,lt/2,half#/1,help#/2,ifa#/2,ifb#/3,logarithm#/1,lt#/2} / {0/0,1/0 ,false/0,logZeroError/0,s/1,true/0,c_1/0,c_2/0,c_3/1,c_4/2,c_5/0,c_6/1,c_7/0,c_8/2,c_9/2,c_10/0,c_11/0 ,c_12/1} - Obligation: innermost runtime complexity wrt. defined symbols {half#,help#,ifa#,ifb#,logarithm#,lt#} and constructors {0 ,1,false,logZeroError,s,true} + Applied Processor: SimplifyRHS + Details: Consider the dependency graph 1:S:half#(s(s(x))) -> c_3(half#(x)) -->_1 half#(s(s(x))) -> c_3(half#(x)):1 2:S:help#(x,y) -> c_4(ifb#(lt(y,x),x,y),lt#(y,x)) -->_2 lt#(s(x),s(y)) -> c_12(lt#(x,y)):6 -->_1 ifb#(true(),x,y) -> c_8(help#(half(x),s(y)),half#(x)):4 3:S:ifa#(true(),x) -> c_6(help#(x,1())) -->_1 help#(x,y) -> c_4(ifb#(lt(y,x),x,y),lt#(y,x)):2 4:S:ifb#(true(),x,y) -> c_8(help#(half(x),s(y)),half#(x)) -->_1 help#(x,y) -> c_4(ifb#(lt(y,x),x,y),lt#(y,x)):2 -->_2 half#(s(s(x))) -> c_3(half#(x)):1 5:S:logarithm#(x) -> c_9(ifa#(lt(0(),x),x),lt#(0(),x)) -->_1 ifa#(true(),x) -> c_6(help#(x,1())):3 6:S:lt#(s(x),s(y)) -> c_12(lt#(x,y)) -->_1 lt#(s(x),s(y)) -> c_12(lt#(x,y)):6 Due to missing edges in the depndency graph, the right-hand sides of following rules could be simplified: logarithm#(x) -> c_9(ifa#(lt(0(),x),x)) * Step 6: NaturalMI MAYBE + Considered Problem: - Strict DPs: half#(s(s(x))) -> c_3(half#(x)) help#(x,y) -> c_4(ifb#(lt(y,x),x,y),lt#(y,x)) ifa#(true(),x) -> c_6(help#(x,1())) ifb#(true(),x,y) -> c_8(help#(half(x),s(y)),half#(x)) logarithm#(x) -> c_9(ifa#(lt(0(),x),x)) lt#(s(x),s(y)) -> c_12(lt#(x,y)) - Weak TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) lt(x,0()) -> false() lt(0(),s(x)) -> true() lt(s(x),s(y)) -> lt(x,y) - Signature: {half/1,help/2,ifa/2,ifb/3,logarithm/1,lt/2,half#/1,help#/2,ifa#/2,ifb#/3,logarithm#/1,lt#/2} / {0/0,1/0 ,false/0,logZeroError/0,s/1,true/0,c_1/0,c_2/0,c_3/1,c_4/2,c_5/0,c_6/1,c_7/0,c_8/2,c_9/1,c_10/0,c_11/0 ,c_12/1} - Obligation: innermost runtime complexity wrt. defined symbols {half#,help#,ifa#,ifb#,logarithm#,lt#} and constructors {0 ,1,false,logZeroError,s,true} + Applied Processor: NaturalMI {miDimension = 1, miDegree = 0, miKind = Algebraic, uargs = UArgs, urules = URules, selector = Just any strict-rules} + Details: We apply a matrix interpretation of kind constructor based matrix interpretation (containing no more than 0 non-zero interpretation-entries in the diagonal of the component-wise maxima): The following argument positions are considered usable: uargs(c_3) = {1}, uargs(c_4) = {1,2}, uargs(c_6) = {1}, uargs(c_8) = {1,2}, uargs(c_9) = {1}, uargs(c_12) = {1} Following symbols are considered usable: {half#,help#,ifa#,ifb#,logarithm#,lt#} TcT has computed the following interpretation: p(0) = [1] p(1) = [0] p(false) = [8] p(half) = [2] p(help) = [1] x1 + [8] x2 + [4] p(ifa) = [2] x1 + [1] x2 + [1] p(ifb) = [1] x2 + [1] x3 + [1] p(logZeroError) = [0] p(logarithm) = [1] x1 + [1] p(lt) = [0] p(s) = [0] p(true) = [0] p(half#) = [0] p(help#) = [8] x2 + [10] p(ifa#) = [11] p(ifb#) = [10] p(logarithm#) = [14] p(lt#) = [0] p(c_1) = [8] p(c_2) = [1] p(c_3) = [4] x1 + [0] p(c_4) = [1] x1 + [8] x2 + [0] p(c_5) = [8] p(c_6) = [1] x1 + [1] p(c_7) = [1] p(c_8) = [1] x1 + [8] x2 + [0] p(c_9) = [1] x1 + [2] p(c_10) = [1] p(c_11) = [4] p(c_12) = [8] x1 + [0] Following rules are strictly oriented: logarithm#(x) = [14] > [13] = c_9(ifa#(lt(0(),x),x)) Following rules are (at-least) weakly oriented: half#(s(s(x))) = [0] >= [0] = c_3(half#(x)) help#(x,y) = [8] y + [10] >= [10] = c_4(ifb#(lt(y,x),x,y),lt#(y,x)) ifa#(true(),x) = [11] >= [11] = c_6(help#(x,1())) ifb#(true(),x,y) = [10] >= [10] = c_8(help#(half(x),s(y)),half#(x)) lt#(s(x),s(y)) = [0] >= [0] = c_12(lt#(x,y)) * Step 7: NaturalMI MAYBE + Considered Problem: - Strict DPs: half#(s(s(x))) -> c_3(half#(x)) help#(x,y) -> c_4(ifb#(lt(y,x),x,y),lt#(y,x)) ifa#(true(),x) -> c_6(help#(x,1())) ifb#(true(),x,y) -> c_8(help#(half(x),s(y)),half#(x)) lt#(s(x),s(y)) -> c_12(lt#(x,y)) - Weak DPs: logarithm#(x) -> c_9(ifa#(lt(0(),x),x)) - Weak TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) lt(x,0()) -> false() lt(0(),s(x)) -> true() lt(s(x),s(y)) -> lt(x,y) - Signature: {half/1,help/2,ifa/2,ifb/3,logarithm/1,lt/2,half#/1,help#/2,ifa#/2,ifb#/3,logarithm#/1,lt#/2} / {0/0,1/0 ,false/0,logZeroError/0,s/1,true/0,c_1/0,c_2/0,c_3/1,c_4/2,c_5/0,c_6/1,c_7/0,c_8/2,c_9/1,c_10/0,c_11/0 ,c_12/1} - Obligation: innermost runtime complexity wrt. defined symbols {half#,help#,ifa#,ifb#,logarithm#,lt#} and constructors {0 ,1,false,logZeroError,s,true} + Applied Processor: NaturalMI {miDimension = 1, miDegree = 0, miKind = Algebraic, uargs = UArgs, urules = URules, selector = Just any strict-rules} + Details: We apply a matrix interpretation of kind constructor based matrix interpretation (containing no more than 0 non-zero interpretation-entries in the diagonal of the component-wise maxima): The following argument positions are considered usable: uargs(c_3) = {1}, uargs(c_4) = {1,2}, uargs(c_6) = {1}, uargs(c_8) = {1,2}, uargs(c_9) = {1}, uargs(c_12) = {1} Following symbols are considered usable: {half#,help#,ifa#,ifb#,logarithm#,lt#} TcT has computed the following interpretation: p(0) = [0] p(1) = [1] p(false) = [0] p(half) = [7] p(help) = [2] x1 + [1] x2 + [0] p(ifa) = [1] x1 + [1] x2 + [8] p(ifb) = [8] x1 + [1] x3 + [1] p(logZeroError) = [1] p(logarithm) = [0] p(lt) = [8] x2 + [0] p(s) = [1] p(true) = [0] p(half#) = [0] p(help#) = [0] p(ifa#) = [15] p(ifb#) = [0] p(logarithm#) = [15] p(lt#) = [0] p(c_1) = [0] p(c_2) = [0] p(c_3) = [4] x1 + [0] p(c_4) = [8] x1 + [4] x2 + [0] p(c_5) = [4] p(c_6) = [1] x1 + [11] p(c_7) = [1] p(c_8) = [8] x1 + [2] x2 + [0] p(c_9) = [1] x1 + [0] p(c_10) = [1] p(c_11) = [2] p(c_12) = [4] x1 + [0] Following rules are strictly oriented: ifa#(true(),x) = [15] > [11] = c_6(help#(x,1())) Following rules are (at-least) weakly oriented: half#(s(s(x))) = [0] >= [0] = c_3(half#(x)) help#(x,y) = [0] >= [0] = c_4(ifb#(lt(y,x),x,y),lt#(y,x)) ifb#(true(),x,y) = [0] >= [0] = c_8(help#(half(x),s(y)),half#(x)) logarithm#(x) = [15] >= [15] = c_9(ifa#(lt(0(),x),x)) lt#(s(x),s(y)) = [0] >= [0] = c_12(lt#(x,y)) * Step 8: Failure MAYBE + Considered Problem: - Strict DPs: half#(s(s(x))) -> c_3(half#(x)) help#(x,y) -> c_4(ifb#(lt(y,x),x,y),lt#(y,x)) ifb#(true(),x,y) -> c_8(help#(half(x),s(y)),half#(x)) lt#(s(x),s(y)) -> c_12(lt#(x,y)) - Weak DPs: ifa#(true(),x) -> c_6(help#(x,1())) logarithm#(x) -> c_9(ifa#(lt(0(),x),x)) - Weak TRS: half(0()) -> 0() half(s(0())) -> 0() half(s(s(x))) -> s(half(x)) lt(x,0()) -> false() lt(0(),s(x)) -> true() lt(s(x),s(y)) -> lt(x,y) - Signature: {half/1,help/2,ifa/2,ifb/3,logarithm/1,lt/2,half#/1,help#/2,ifa#/2,ifb#/3,logarithm#/1,lt#/2} / {0/0,1/0 ,false/0,logZeroError/0,s/1,true/0,c_1/0,c_2/0,c_3/1,c_4/2,c_5/0,c_6/1,c_7/0,c_8/2,c_9/1,c_10/0,c_11/0 ,c_12/1} - Obligation: innermost runtime complexity wrt. defined symbols {half#,help#,ifa#,ifb#,logarithm#,lt#} and constructors {0 ,1,false,logZeroError,s,true} + Applied Processor: EmptyProcessor + Details: The problem is still open. MAYBE