*** 1 Progress [(?,O(n^2))] *** Considered Problem: Strict DP Rules: Strict TRS Rules: gcd(0(),y) -> y gcd(s(x),0()) -> s(x) gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(x,s(y)) -> pred(minus(x,y)) pred(s(x)) -> x Weak DP Rules: Weak TRS Rules: Signature: {gcd/2,if_gcd/3,le/2,minus/2,pred/1} / {0/0,false/0,s/1,true/0} Obligation: Innermost basic terms: {gcd,if_gcd,le,minus,pred}/{0,false,s,true} Applied Processor: DependencyPairs {dpKind_ = DT} Proof: We add the following dependency tuples: Strict DPs gcd#(0(),y) -> c_1() gcd#(s(x),0()) -> c_2() gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)) if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) le#(0(),y) -> c_6() le#(s(x),0()) -> c_7() le#(s(x),s(y)) -> c_8(le#(x,y)) minus#(x,0()) -> c_9() minus#(x,s(y)) -> c_10(pred#(minus(x,y)),minus#(x,y)) pred#(s(x)) -> c_11() Weak DPs and mark the set of starting terms. *** 1.1 Progress [(?,O(n^2))] *** Considered Problem: Strict DP Rules: gcd#(0(),y) -> c_1() gcd#(s(x),0()) -> c_2() gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)) if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) le#(0(),y) -> c_6() le#(s(x),0()) -> c_7() le#(s(x),s(y)) -> c_8(le#(x,y)) minus#(x,0()) -> c_9() minus#(x,s(y)) -> c_10(pred#(minus(x,y)),minus#(x,y)) pred#(s(x)) -> c_11() Strict TRS Rules: Weak DP Rules: Weak TRS Rules: gcd(0(),y) -> y gcd(s(x),0()) -> s(x) gcd(s(x),s(y)) -> if_gcd(le(y,x),s(x),s(y)) if_gcd(false(),s(x),s(y)) -> gcd(minus(y,x),s(x)) if_gcd(true(),s(x),s(y)) -> gcd(minus(x,y),s(y)) le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(x,s(y)) -> pred(minus(x,y)) pred(s(x)) -> x Signature: {gcd/2,if_gcd/3,le/2,minus/2,pred/1,gcd#/2,if_gcd#/3,le#/2,minus#/2,pred#/1} / {0/0,false/0,s/1,true/0,c_1/0,c_2/0,c_3/2,c_4/2,c_5/2,c_6/0,c_7/0,c_8/1,c_9/0,c_10/2,c_11/0} Obligation: Innermost basic terms: {gcd#,if_gcd#,le#,minus#,pred#}/{0,false,s,true} Applied Processor: UsableRules Proof: We replace rewrite rules by usable rules: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(x,s(y)) -> pred(minus(x,y)) pred(s(x)) -> x gcd#(0(),y) -> c_1() gcd#(s(x),0()) -> c_2() gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)) if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) le#(0(),y) -> c_6() le#(s(x),0()) -> c_7() le#(s(x),s(y)) -> c_8(le#(x,y)) minus#(x,0()) -> c_9() minus#(x,s(y)) -> c_10(pred#(minus(x,y)),minus#(x,y)) pred#(s(x)) -> c_11() *** 1.1.1 Progress [(?,O(n^2))] *** Considered Problem: Strict DP Rules: gcd#(0(),y) -> c_1() gcd#(s(x),0()) -> c_2() gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)) if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) le#(0(),y) -> c_6() le#(s(x),0()) -> c_7() le#(s(x),s(y)) -> c_8(le#(x,y)) minus#(x,0()) -> c_9() minus#(x,s(y)) -> c_10(pred#(minus(x,y)),minus#(x,y)) pred#(s(x)) -> c_11() Strict TRS Rules: Weak DP Rules: Weak TRS Rules: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(x,s(y)) -> pred(minus(x,y)) pred(s(x)) -> x Signature: {gcd/2,if_gcd/3,le/2,minus/2,pred/1,gcd#/2,if_gcd#/3,le#/2,minus#/2,pred#/1} / {0/0,false/0,s/1,true/0,c_1/0,c_2/0,c_3/2,c_4/2,c_5/2,c_6/0,c_7/0,c_8/1,c_9/0,c_10/2,c_11/0} Obligation: Innermost basic terms: {gcd#,if_gcd#,le#,minus#,pred#}/{0,false,s,true} Applied Processor: PredecessorEstimation {onSelection = all simple predecessor estimation selector} Proof: We estimate the number of application of {1,2,6,7,9,11} by application of Pre({1,2,6,7,9,11}) = {3,4,5,8,10}. Here rules are labelled as follows: 1: gcd#(0(),y) -> c_1() 2: gcd#(s(x),0()) -> c_2() 3: gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)) ,le#(y,x)) 4: if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)) ,minus#(y,x)) 5: if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)) ,minus#(x,y)) 6: le#(0(),y) -> c_6() 7: le#(s(x),0()) -> c_7() 8: le#(s(x),s(y)) -> c_8(le#(x,y)) 9: minus#(x,0()) -> c_9() 10: minus#(x,s(y)) -> c_10(pred#(minus(x,y)) ,minus#(x,y)) 11: pred#(s(x)) -> c_11() *** 1.1.1.1 Progress [(?,O(n^2))] *** Considered Problem: Strict DP Rules: gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)) if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) le#(s(x),s(y)) -> c_8(le#(x,y)) minus#(x,s(y)) -> c_10(pred#(minus(x,y)),minus#(x,y)) Strict TRS Rules: Weak DP Rules: gcd#(0(),y) -> c_1() gcd#(s(x),0()) -> c_2() le#(0(),y) -> c_6() le#(s(x),0()) -> c_7() minus#(x,0()) -> c_9() pred#(s(x)) -> c_11() Weak TRS Rules: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(x,s(y)) -> pred(minus(x,y)) pred(s(x)) -> x Signature: {gcd/2,if_gcd/3,le/2,minus/2,pred/1,gcd#/2,if_gcd#/3,le#/2,minus#/2,pred#/1} / {0/0,false/0,s/1,true/0,c_1/0,c_2/0,c_3/2,c_4/2,c_5/2,c_6/0,c_7/0,c_8/1,c_9/0,c_10/2,c_11/0} Obligation: Innermost basic terms: {gcd#,if_gcd#,le#,minus#,pred#}/{0,false,s,true} Applied Processor: RemoveWeakSuffixes Proof: Consider the dependency graph 1:S:gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)) -->_2 le#(s(x),s(y)) -> c_8(le#(x,y)):4 -->_1 if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)):3 -->_1 if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)):2 -->_2 le#(s(x),0()) -> c_7():9 -->_2 le#(0(),y) -> c_6():8 2:S:if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) -->_2 minus#(x,s(y)) -> c_10(pred#(minus(x,y)),minus#(x,y)):5 -->_2 minus#(x,0()) -> c_9():10 -->_1 gcd#(0(),y) -> c_1():6 -->_1 gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)):1 3:S:if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) -->_2 minus#(x,s(y)) -> c_10(pred#(minus(x,y)),minus#(x,y)):5 -->_2 minus#(x,0()) -> c_9():10 -->_1 gcd#(0(),y) -> c_1():6 -->_1 gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)):1 4:S:le#(s(x),s(y)) -> c_8(le#(x,y)) -->_1 le#(s(x),0()) -> c_7():9 -->_1 le#(0(),y) -> c_6():8 -->_1 le#(s(x),s(y)) -> c_8(le#(x,y)):4 5:S:minus#(x,s(y)) -> c_10(pred#(minus(x,y)),minus#(x,y)) -->_1 pred#(s(x)) -> c_11():11 -->_2 minus#(x,0()) -> c_9():10 -->_2 minus#(x,s(y)) -> c_10(pred#(minus(x,y)),minus#(x,y)):5 6:W:gcd#(0(),y) -> c_1() 7:W:gcd#(s(x),0()) -> c_2() 8:W:le#(0(),y) -> c_6() 9:W:le#(s(x),0()) -> c_7() 10:W:minus#(x,0()) -> c_9() 11:W:pred#(s(x)) -> c_11() The following weak DPs constitute a sub-graph of the DG that is closed under successors. The DPs are removed. 7: gcd#(s(x),0()) -> c_2() 6: gcd#(0(),y) -> c_1() 10: minus#(x,0()) -> c_9() 11: pred#(s(x)) -> c_11() 8: le#(0(),y) -> c_6() 9: le#(s(x),0()) -> c_7() *** 1.1.1.1.1 Progress [(?,O(n^2))] *** Considered Problem: Strict DP Rules: gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)) if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) le#(s(x),s(y)) -> c_8(le#(x,y)) minus#(x,s(y)) -> c_10(pred#(minus(x,y)),minus#(x,y)) Strict TRS Rules: Weak DP Rules: Weak TRS Rules: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(x,s(y)) -> pred(minus(x,y)) pred(s(x)) -> x Signature: {gcd/2,if_gcd/3,le/2,minus/2,pred/1,gcd#/2,if_gcd#/3,le#/2,minus#/2,pred#/1} / {0/0,false/0,s/1,true/0,c_1/0,c_2/0,c_3/2,c_4/2,c_5/2,c_6/0,c_7/0,c_8/1,c_9/0,c_10/2,c_11/0} Obligation: Innermost basic terms: {gcd#,if_gcd#,le#,minus#,pred#}/{0,false,s,true} Applied Processor: SimplifyRHS Proof: Consider the dependency graph 1:S:gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)) -->_2 le#(s(x),s(y)) -> c_8(le#(x,y)):4 -->_1 if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)):3 -->_1 if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)):2 2:S:if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) -->_2 minus#(x,s(y)) -> c_10(pred#(minus(x,y)),minus#(x,y)):5 -->_1 gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)):1 3:S:if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) -->_2 minus#(x,s(y)) -> c_10(pred#(minus(x,y)),minus#(x,y)):5 -->_1 gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)):1 4:S:le#(s(x),s(y)) -> c_8(le#(x,y)) -->_1 le#(s(x),s(y)) -> c_8(le#(x,y)):4 5:S:minus#(x,s(y)) -> c_10(pred#(minus(x,y)),minus#(x,y)) -->_2 minus#(x,s(y)) -> c_10(pred#(minus(x,y)),minus#(x,y)):5 Due to missing edges in the depndency graph, the right-hand sides of following rules could be simplified: minus#(x,s(y)) -> c_10(minus#(x,y)) *** 1.1.1.1.1.1 Progress [(?,O(n^2))] *** Considered Problem: Strict DP Rules: gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)) if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) le#(s(x),s(y)) -> c_8(le#(x,y)) minus#(x,s(y)) -> c_10(minus#(x,y)) Strict TRS Rules: Weak DP Rules: Weak TRS Rules: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(x,s(y)) -> pred(minus(x,y)) pred(s(x)) -> x Signature: {gcd/2,if_gcd/3,le/2,minus/2,pred/1,gcd#/2,if_gcd#/3,le#/2,minus#/2,pred#/1} / {0/0,false/0,s/1,true/0,c_1/0,c_2/0,c_3/2,c_4/2,c_5/2,c_6/0,c_7/0,c_8/1,c_9/0,c_10/1,c_11/0} Obligation: Innermost basic terms: {gcd#,if_gcd#,le#,minus#,pred#}/{0,false,s,true} Applied Processor: PredecessorEstimationCP {onSelectionCP = any intersect of rules of CDG leaf and strict-rules, withComplexityPair = NaturalMI {miDimension = 3, miDegree = 2, miKind = Algebraic, uargs = UArgs, urules = URules, selector = Nothing, greedy = NoGreedy}} Proof: We first use the processor NaturalMI {miDimension = 3, miDegree = 2, miKind = Algebraic, uargs = UArgs, urules = URules, selector = Nothing, greedy = NoGreedy} to orient following rules strictly: 4: le#(s(x),s(y)) -> c_8(le#(x,y)) The strictly oriented rules are moved into the weak component. *** 1.1.1.1.1.1.1 Progress [(?,O(n^2))] *** Considered Problem: Strict DP Rules: gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)) if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) le#(s(x),s(y)) -> c_8(le#(x,y)) minus#(x,s(y)) -> c_10(minus#(x,y)) Strict TRS Rules: Weak DP Rules: Weak TRS Rules: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(x,s(y)) -> pred(minus(x,y)) pred(s(x)) -> x Signature: {gcd/2,if_gcd/3,le/2,minus/2,pred/1,gcd#/2,if_gcd#/3,le#/2,minus#/2,pred#/1} / {0/0,false/0,s/1,true/0,c_1/0,c_2/0,c_3/2,c_4/2,c_5/2,c_6/0,c_7/0,c_8/1,c_9/0,c_10/1,c_11/0} Obligation: Innermost basic terms: {gcd#,if_gcd#,le#,minus#,pred#}/{0,false,s,true} Applied Processor: NaturalMI {miDimension = 3, miDegree = 2, miKind = Algebraic, uargs = UArgs, urules = URules, selector = Just first alternative for predecessorEstimation any intersect of rules of CDG leaf and strict-rules, greedy = NoGreedy} Proof: We apply a matrix interpretation of kind constructor based matrix interpretation (containing no more than 2 non-zero interpretation-entries in the diagonal of the component-wise maxima): The following argument positions are considered usable: uargs(c_3) = {1,2}, uargs(c_4) = {1,2}, uargs(c_5) = {1,2}, uargs(c_8) = {1}, uargs(c_10) = {1} Following symbols are considered usable: {le,minus,pred,gcd#,if_gcd#,le#,minus#,pred#} TcT has computed the following interpretation: p(0) = [1] [0] [0] p(false) = [1] [0] [0] p(gcd) = [0] [0] [0] p(if_gcd) = [0] [0] [0] p(le) = [1 0 0] [1] [0 0 0] x1 + [1] [1 1 0] [1] p(minus) = [1 0 0] [0 0 0] [1] [1 1 0] x1 + [0 0 1] x2 + [0] [0 1 1] [0 0 0] [0] p(pred) = [1 0 0] [0] [1 0 0] x1 + [0] [0 0 1] [0] p(s) = [1 1 1] [0] [0 0 1] x1 + [0] [0 0 1] [1] p(true) = [0] [0] [0] p(gcd#) = [1 0 1] [1 0 0] [0] [0 0 0] x1 + [0 1 1] x2 + [0] [0 0 0] [1 0 1] [1] p(if_gcd#) = [0 0 0] [1 0 0] [1 0 0] [1] [0 0 0] x1 + [1 0 1] x2 + [0 0 0] x3 + [0] [0 0 1] [1 1 1] [1 1 1] [0] p(le#) = [0 0 0] [0 0 1] [0] [1 0 0] x1 + [0 0 0] x2 + [0] [0 0 0] [0 1 1] [1] p(minus#) = [0 0 0] [0 0 0] [0] [0 0 0] x1 + [1 1 1] x2 + [0] [1 1 0] [0 0 0] [0] p(pred#) = [0] [0] [0] p(c_1) = [0] [0] [0] p(c_2) = [0] [0] [0] p(c_3) = [1 0 0] [1 0 0] [0] [0 0 0] x1 + [0 0 0] x2 + [1] [0 0 0] [0 1 0] [0] p(c_4) = [1 0 0] [1 0 0] [0] [0 0 0] x1 + [0 1 0] x2 + [1] [1 1 0] [0 0 0] [0] p(c_5) = [1 0 0] [1 0 0] [0] [0 0 0] x1 + [0 0 1] x2 + [0] [1 0 0] [0 0 0] [0] p(c_6) = [0] [0] [0] p(c_7) = [0] [0] [0] p(c_8) = [1 0 0] [0] [0 1 0] x1 + [0] [1 0 0] [0] p(c_9) = [0] [0] [0] p(c_10) = [1 0 0] [0] [0 0 0] x1 + [0] [0 0 1] [0] p(c_11) = [0] [0] [0] Following rules are strictly oriented: le#(s(x),s(y)) = [0 0 0] [0 0 1] [1] [1 1 1] x + [0 0 0] y + [0] [0 0 0] [0 0 2] [2] > [0 0 0] [0 0 1] [0] [1 0 0] x + [0 0 0] y + [0] [0 0 0] [0 0 1] [0] = c_8(le#(x,y)) Following rules are (at-least) weakly oriented: gcd#(s(x),s(y)) = [1 1 2] [1 1 1] [1] [0 0 0] x + [0 0 2] y + [1] [0 0 0] [1 1 2] [2] >= [1 1 2] [1 1 1] [1] [0 0 0] x + [0 0 0] y + [1] [0 0 0] [1 0 0] [0] = c_3(if_gcd#(le(y,x),s(x),s(y)) ,le#(y,x)) if_gcd#(false(),s(x),s(y)) = [1 1 1] [1 1 1] [1] [1 1 2] x + [0 0 0] y + [1] [1 1 3] [1 1 3] [2] >= [1 1 1] [1 1 1] [1] [1 1 1] x + [0 0 0] y + [1] [1 1 3] [1 1 1] [2] = c_4(gcd#(minus(y,x),s(x)) ,minus#(y,x)) if_gcd#(true(),s(x),s(y)) = [1 1 1] [1 1 1] [1] [1 1 2] x + [0 0 0] y + [1] [1 1 3] [1 1 3] [2] >= [1 1 1] [1 1 1] [1] [1 1 0] x + [0 0 0] y + [0] [1 1 1] [1 1 1] [1] = c_5(gcd#(minus(x,y),s(y)) ,minus#(x,y)) minus#(x,s(y)) = [0 0 0] [0 0 0] [0] [0 0 0] x + [1 1 3] y + [1] [1 1 0] [0 0 0] [0] >= [0 0 0] [0] [0 0 0] x + [0] [1 1 0] [0] = c_10(minus#(x,y)) le(0(),y) = [2] [1] [2] >= [0] [0] [0] = true() le(s(x),0()) = [1 1 1] [1] [0 0 0] x + [1] [1 1 2] [1] >= [1] [0] [0] = false() le(s(x),s(y)) = [1 1 1] [1] [0 0 0] x + [1] [1 1 2] [1] >= [1 0 0] [1] [0 0 0] x + [1] [1 1 0] [1] = le(x,y) minus(x,0()) = [1 0 0] [1] [1 1 0] x + [0] [0 1 1] [0] >= [1 0 0] [0] [0 1 0] x + [0] [0 0 1] [0] = x minus(x,s(y)) = [1 0 0] [0 0 0] [1] [1 1 0] x + [0 0 1] y + [1] [0 1 1] [0 0 0] [0] >= [1 0 0] [1] [1 0 0] x + [1] [0 1 1] [0] = pred(minus(x,y)) pred(s(x)) = [1 1 1] [0] [1 1 1] x + [0] [0 0 1] [1] >= [1 0 0] [0] [0 1 0] x + [0] [0 0 1] [0] = x *** 1.1.1.1.1.1.1.1 Progress [(?,O(1))] *** Considered Problem: Strict DP Rules: gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)) if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) minus#(x,s(y)) -> c_10(minus#(x,y)) Strict TRS Rules: Weak DP Rules: le#(s(x),s(y)) -> c_8(le#(x,y)) Weak TRS Rules: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(x,s(y)) -> pred(minus(x,y)) pred(s(x)) -> x Signature: {gcd/2,if_gcd/3,le/2,minus/2,pred/1,gcd#/2,if_gcd#/3,le#/2,minus#/2,pred#/1} / {0/0,false/0,s/1,true/0,c_1/0,c_2/0,c_3/2,c_4/2,c_5/2,c_6/0,c_7/0,c_8/1,c_9/0,c_10/1,c_11/0} Obligation: Innermost basic terms: {gcd#,if_gcd#,le#,minus#,pred#}/{0,false,s,true} Applied Processor: Assumption Proof: () *** 1.1.1.1.1.1.2 Progress [(?,O(n^2))] *** Considered Problem: Strict DP Rules: gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)) if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) minus#(x,s(y)) -> c_10(minus#(x,y)) Strict TRS Rules: Weak DP Rules: le#(s(x),s(y)) -> c_8(le#(x,y)) Weak TRS Rules: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(x,s(y)) -> pred(minus(x,y)) pred(s(x)) -> x Signature: {gcd/2,if_gcd/3,le/2,minus/2,pred/1,gcd#/2,if_gcd#/3,le#/2,minus#/2,pred#/1} / {0/0,false/0,s/1,true/0,c_1/0,c_2/0,c_3/2,c_4/2,c_5/2,c_6/0,c_7/0,c_8/1,c_9/0,c_10/1,c_11/0} Obligation: Innermost basic terms: {gcd#,if_gcd#,le#,minus#,pred#}/{0,false,s,true} Applied Processor: RemoveWeakSuffixes Proof: Consider the dependency graph 1:S:gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)) -->_2 le#(s(x),s(y)) -> c_8(le#(x,y)):5 -->_1 if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)):3 -->_1 if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)):2 2:S:if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) -->_2 minus#(x,s(y)) -> c_10(minus#(x,y)):4 -->_1 gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)):1 3:S:if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) -->_2 minus#(x,s(y)) -> c_10(minus#(x,y)):4 -->_1 gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)):1 4:S:minus#(x,s(y)) -> c_10(minus#(x,y)) -->_1 minus#(x,s(y)) -> c_10(minus#(x,y)):4 5:W:le#(s(x),s(y)) -> c_8(le#(x,y)) -->_1 le#(s(x),s(y)) -> c_8(le#(x,y)):5 The following weak DPs constitute a sub-graph of the DG that is closed under successors. The DPs are removed. 5: le#(s(x),s(y)) -> c_8(le#(x,y)) *** 1.1.1.1.1.1.2.1 Progress [(?,O(n^2))] *** Considered Problem: Strict DP Rules: gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)) if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) minus#(x,s(y)) -> c_10(minus#(x,y)) Strict TRS Rules: Weak DP Rules: Weak TRS Rules: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(x,s(y)) -> pred(minus(x,y)) pred(s(x)) -> x Signature: {gcd/2,if_gcd/3,le/2,minus/2,pred/1,gcd#/2,if_gcd#/3,le#/2,minus#/2,pred#/1} / {0/0,false/0,s/1,true/0,c_1/0,c_2/0,c_3/2,c_4/2,c_5/2,c_6/0,c_7/0,c_8/1,c_9/0,c_10/1,c_11/0} Obligation: Innermost basic terms: {gcd#,if_gcd#,le#,minus#,pred#}/{0,false,s,true} Applied Processor: SimplifyRHS Proof: Consider the dependency graph 1:S:gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)) -->_1 if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)):3 -->_1 if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)):2 2:S:if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) -->_2 minus#(x,s(y)) -> c_10(minus#(x,y)):4 -->_1 gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)):1 3:S:if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) -->_2 minus#(x,s(y)) -> c_10(minus#(x,y)):4 -->_1 gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y)),le#(y,x)):1 4:S:minus#(x,s(y)) -> c_10(minus#(x,y)) -->_1 minus#(x,s(y)) -> c_10(minus#(x,y)):4 Due to missing edges in the depndency graph, the right-hand sides of following rules could be simplified: gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y))) *** 1.1.1.1.1.1.2.1.1 Progress [(?,O(n^2))] *** Considered Problem: Strict DP Rules: gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y))) if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) minus#(x,s(y)) -> c_10(minus#(x,y)) Strict TRS Rules: Weak DP Rules: Weak TRS Rules: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(x,s(y)) -> pred(minus(x,y)) pred(s(x)) -> x Signature: {gcd/2,if_gcd/3,le/2,minus/2,pred/1,gcd#/2,if_gcd#/3,le#/2,minus#/2,pred#/1} / {0/0,false/0,s/1,true/0,c_1/0,c_2/0,c_3/1,c_4/2,c_5/2,c_6/0,c_7/0,c_8/1,c_9/0,c_10/1,c_11/0} Obligation: Innermost basic terms: {gcd#,if_gcd#,le#,minus#,pred#}/{0,false,s,true} Applied Processor: PredecessorEstimationCP {onSelectionCP = any intersect of rules of CDG leaf and strict-rules, withComplexityPair = NaturalPI {shape = Mixed 2, restrict = Restrict, uargs = UArgs, urules = URules, selector = Nothing, greedy = NoGreedy}} Proof: We first use the processor NaturalPI {shape = Mixed 2, restrict = Restrict, uargs = UArgs, urules = URules, selector = Nothing, greedy = NoGreedy} to orient following rules strictly: 1: gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y))) 4: minus#(x,s(y)) -> c_10(minus#(x ,y)) Consider the set of all dependency pairs 1: gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y))) 2: if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)) ,minus#(y,x)) 3: if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)) ,minus#(x,y)) 4: minus#(x,s(y)) -> c_10(minus#(x ,y)) Processor NaturalPI {shape = Mixed 2, restrict = Restrict, uargs = UArgs, urules = URules, selector = Nothing, greedy = NoGreedy}induces the complexity certificateTIME (?,O(n^2)) SPACE(?,?)on application of the dependency pairs {1,4} These cover all (indirect) predecessors of dependency pairs {1,2,3,4} their number of applications is equally bounded. The dependency pairs are shifted into the weak component. *** 1.1.1.1.1.1.2.1.1.1 Progress [(?,O(n^2))] *** Considered Problem: Strict DP Rules: gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y))) if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) minus#(x,s(y)) -> c_10(minus#(x,y)) Strict TRS Rules: Weak DP Rules: Weak TRS Rules: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(x,s(y)) -> pred(minus(x,y)) pred(s(x)) -> x Signature: {gcd/2,if_gcd/3,le/2,minus/2,pred/1,gcd#/2,if_gcd#/3,le#/2,minus#/2,pred#/1} / {0/0,false/0,s/1,true/0,c_1/0,c_2/0,c_3/1,c_4/2,c_5/2,c_6/0,c_7/0,c_8/1,c_9/0,c_10/1,c_11/0} Obligation: Innermost basic terms: {gcd#,if_gcd#,le#,minus#,pred#}/{0,false,s,true} Applied Processor: NaturalPI {shape = Mixed 2, restrict = Restrict, uargs = UArgs, urules = URules, selector = Just first alternative for predecessorEstimation any intersect of rules of CDG leaf and strict-rules, greedy = NoGreedy} Proof: We apply a polynomial interpretation of kind constructor-based(mixed(2)): The following argument positions are considered usable: uargs(c_3) = {1}, uargs(c_4) = {1,2}, uargs(c_5) = {1,2}, uargs(c_10) = {1} Following symbols are considered usable: {minus,pred,gcd#,if_gcd#,le#,minus#,pred#} TcT has computed the following interpretation: p(0) = 0 p(false) = 0 p(gcd) = 2 + x1*x2 p(if_gcd) = x1*x3 + x1^2 + 2*x2^2 + 2*x3^2 p(le) = 0 p(minus) = x1 p(pred) = x1 p(s) = 1 + x1 p(true) = 0 p(gcd#) = 2 + x1*x2 p(if_gcd#) = 1 + x2*x3 p(le#) = x1^2 + x2 + x2^2 p(minus#) = x2 p(pred#) = 2 + 2*x1 p(c_1) = 1 p(c_2) = 1 p(c_3) = x1 p(c_4) = x1 + x2 p(c_5) = x1 + x2 p(c_6) = 0 p(c_7) = 1 p(c_8) = 1 p(c_9) = 0 p(c_10) = x1 p(c_11) = 0 Following rules are strictly oriented: gcd#(s(x),s(y)) = 3 + x + x*y + y > 2 + x + x*y + y = c_3(if_gcd#(le(y,x),s(x),s(y))) minus#(x,s(y)) = 1 + y > y = c_10(minus#(x,y)) Following rules are (at-least) weakly oriented: if_gcd#(false(),s(x),s(y)) = 2 + x + x*y + y >= 2 + x + x*y + y = c_4(gcd#(minus(y,x),s(x)) ,minus#(y,x)) if_gcd#(true(),s(x),s(y)) = 2 + x + x*y + y >= 2 + x + x*y + y = c_5(gcd#(minus(x,y),s(y)) ,minus#(x,y)) minus(x,0()) = x >= x = x minus(x,s(y)) = x >= x = pred(minus(x,y)) pred(s(x)) = 1 + x >= x = x *** 1.1.1.1.1.1.2.1.1.1.1 Progress [(?,O(1))] *** Considered Problem: Strict DP Rules: if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) Strict TRS Rules: Weak DP Rules: gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y))) minus#(x,s(y)) -> c_10(minus#(x,y)) Weak TRS Rules: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(x,s(y)) -> pred(minus(x,y)) pred(s(x)) -> x Signature: {gcd/2,if_gcd/3,le/2,minus/2,pred/1,gcd#/2,if_gcd#/3,le#/2,minus#/2,pred#/1} / {0/0,false/0,s/1,true/0,c_1/0,c_2/0,c_3/1,c_4/2,c_5/2,c_6/0,c_7/0,c_8/1,c_9/0,c_10/1,c_11/0} Obligation: Innermost basic terms: {gcd#,if_gcd#,le#,minus#,pred#}/{0,false,s,true} Applied Processor: Assumption Proof: () *** 1.1.1.1.1.1.2.1.1.2 Progress [(O(1),O(1))] *** Considered Problem: Strict DP Rules: Strict TRS Rules: Weak DP Rules: gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y))) if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) minus#(x,s(y)) -> c_10(minus#(x,y)) Weak TRS Rules: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(x,s(y)) -> pred(minus(x,y)) pred(s(x)) -> x Signature: {gcd/2,if_gcd/3,le/2,minus/2,pred/1,gcd#/2,if_gcd#/3,le#/2,minus#/2,pred#/1} / {0/0,false/0,s/1,true/0,c_1/0,c_2/0,c_3/1,c_4/2,c_5/2,c_6/0,c_7/0,c_8/1,c_9/0,c_10/1,c_11/0} Obligation: Innermost basic terms: {gcd#,if_gcd#,le#,minus#,pred#}/{0,false,s,true} Applied Processor: RemoveWeakSuffixes Proof: Consider the dependency graph 1:W:gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y))) -->_1 if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)):3 -->_1 if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)):2 2:W:if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)),minus#(y,x)) -->_2 minus#(x,s(y)) -> c_10(minus#(x,y)):4 -->_1 gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y))):1 3:W:if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)),minus#(x,y)) -->_2 minus#(x,s(y)) -> c_10(minus#(x,y)):4 -->_1 gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y))):1 4:W:minus#(x,s(y)) -> c_10(minus#(x,y)) -->_1 minus#(x,s(y)) -> c_10(minus#(x,y)):4 The following weak DPs constitute a sub-graph of the DG that is closed under successors. The DPs are removed. 1: gcd#(s(x),s(y)) -> c_3(if_gcd#(le(y,x),s(x),s(y))) 3: if_gcd#(true(),s(x),s(y)) -> c_5(gcd#(minus(x,y),s(y)) ,minus#(x,y)) 2: if_gcd#(false(),s(x),s(y)) -> c_4(gcd#(minus(y,x),s(x)) ,minus#(y,x)) 4: minus#(x,s(y)) -> c_10(minus#(x ,y)) *** 1.1.1.1.1.1.2.1.1.2.1 Progress [(O(1),O(1))] *** Considered Problem: Strict DP Rules: Strict TRS Rules: Weak DP Rules: Weak TRS Rules: le(0(),y) -> true() le(s(x),0()) -> false() le(s(x),s(y)) -> le(x,y) minus(x,0()) -> x minus(x,s(y)) -> pred(minus(x,y)) pred(s(x)) -> x Signature: {gcd/2,if_gcd/3,le/2,minus/2,pred/1,gcd#/2,if_gcd#/3,le#/2,minus#/2,pred#/1} / {0/0,false/0,s/1,true/0,c_1/0,c_2/0,c_3/1,c_4/2,c_5/2,c_6/0,c_7/0,c_8/1,c_9/0,c_10/1,c_11/0} Obligation: Innermost basic terms: {gcd#,if_gcd#,le#,minus#,pred#}/{0,false,s,true} Applied Processor: EmptyProcessor Proof: The problem is already closed. The intended complexity is O(1).