10.01/3.62 MAYBE 10.01/3.62 proof of /export/starexec/sandbox/benchmark/theBenchmark.xml 10.01/3.62 # AProVE Commit ID: 48fb2092695e11cc9f56e44b17a92a5f88ffb256 marcel 20180622 unpublished dirty 10.01/3.62 10.01/3.62 10.01/3.62 Quasi decreasingness of the given CTRS could not be shown: 10.01/3.62 10.01/3.62 (0) CTRS 10.01/3.62 (1) CTRSToQTRSProof [SOUND, 0 ms] 10.01/3.62 (2) QTRS 10.01/3.62 (3) QTRSRRRProof [EQUIVALENT, 52 ms] 10.01/3.62 (4) QTRS 10.01/3.62 (5) DependencyPairsProof [EQUIVALENT, 0 ms] 10.01/3.62 (6) QDP 10.01/3.62 (7) DependencyGraphProof [EQUIVALENT, 0 ms] 10.01/3.62 (8) AND 10.01/3.62 (9) QDP 10.01/3.62 (10) UsableRulesProof [EQUIVALENT, 0 ms] 10.01/3.62 (11) QDP 10.01/3.62 (12) QDPSizeChangeProof [EQUIVALENT, 0 ms] 10.01/3.62 (13) YES 10.01/3.62 (14) QDP 10.01/3.62 (15) UsableRulesProof [EQUIVALENT, 0 ms] 10.01/3.62 (16) QDP 10.01/3.62 (17) TransformationProof [EQUIVALENT, 0 ms] 10.01/3.62 (18) QDP 10.01/3.62 (19) TransformationProof [EQUIVALENT, 0 ms] 10.01/3.62 (20) QDP 10.01/3.62 (21) MRRProof [EQUIVALENT, 0 ms] 10.01/3.62 (22) QDP 10.01/3.62 (23) TransformationProof [EQUIVALENT, 0 ms] 10.01/3.62 (24) QDP 10.01/3.62 (25) NonTerminationLoopProof [COMPLETE, 0 ms] 10.01/3.62 (26) NO 10.01/3.62 10.01/3.62 10.01/3.62 ---------------------------------------- 10.01/3.62 10.01/3.62 (0) 10.01/3.62 Obligation: 10.01/3.62 Conditional term rewrite system: 10.01/3.62 The TRS R consists of the following rules: 10.01/3.62 10.01/3.62 gcd(x, 0) -> x 10.01/3.62 gcd(0, x) -> x 10.01/3.62 iadd(y) -> tp2(0, y) 10.01/3.62 iadd(add(x, y)) -> tp2(x, y) 10.01/3.62 10.01/3.62 The conditional TRS C consists of the following conditional rules: 10.01/3.62 10.01/3.62 gcd(z, y) -> gcd(x, y) <= iadd(z) -> tp2(x, y) 10.01/3.62 gcd(y, z) -> gcd(x, y) <= iadd(z) -> tp2(x, y) 10.01/3.62 iadd(s(z)) -> tp2(s(x), y) <= iadd(z) -> tp2(x, y) 10.01/3.62 10.01/3.62 10.01/3.62 ---------------------------------------- 10.01/3.62 10.01/3.62 (1) CTRSToQTRSProof (SOUND) 10.01/3.62 The conditional rules have been transormed into unconditional rules according to [CTRS,AAECCNOC]. 10.01/3.62 ---------------------------------------- 10.01/3.62 10.01/3.62 (2) 10.01/3.62 Obligation: 10.01/3.62 Q restricted rewrite system: 10.01/3.62 The TRS R consists of the following rules: 10.01/3.62 10.01/3.62 gcd(z, y) -> U1(iadd(z), y) 10.01/3.62 U1(tp2(x, y), y) -> gcd(x, y) 10.01/3.62 gcd(y, z) -> U2(iadd(z), y) 10.01/3.62 U2(tp2(x, y), y) -> gcd(x, y) 10.01/3.62 iadd(s(z)) -> U3(iadd(z)) 10.01/3.62 U3(tp2(x, y)) -> tp2(s(x), y) 10.01/3.62 gcd(x, 0) -> x 10.01/3.62 gcd(0, x) -> x 10.01/3.62 iadd(y) -> tp2(0, y) 10.01/3.62 iadd(add(x, y)) -> tp2(x, y) 10.01/3.62 10.01/3.62 Q is empty. 10.01/3.62 10.01/3.62 ---------------------------------------- 10.01/3.63 10.01/3.63 (3) QTRSRRRProof (EQUIVALENT) 10.01/3.63 Used ordering: 10.01/3.63 Polynomial interpretation [POLO]: 10.01/3.63 10.01/3.63 POL(0) = 0 10.01/3.63 POL(U1(x_1, x_2)) = x_1 + 2*x_2 10.01/3.63 POL(U2(x_1, x_2)) = x_1 + 2*x_2 10.01/3.63 POL(U3(x_1)) = x_1 10.01/3.63 POL(add(x_1, x_2)) = 1 + 2*x_1 + 2*x_2 10.01/3.63 POL(gcd(x_1, x_2)) = 1 + 2*x_1 + 2*x_2 10.01/3.63 POL(iadd(x_1)) = 1 + x_1 10.01/3.63 POL(s(x_1)) = x_1 10.01/3.63 POL(tp2(x_1, x_2)) = 1 + 2*x_1 + x_2 10.01/3.63 With this ordering the following rules can be removed by the rule removal processor [LPAR04] because they are oriented strictly: 10.01/3.63 10.01/3.63 gcd(x, 0) -> x 10.01/3.63 gcd(0, x) -> x 10.01/3.63 iadd(add(x, y)) -> tp2(x, y) 10.01/3.63 10.01/3.63 10.01/3.63 10.01/3.63 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (4) 10.01/3.63 Obligation: 10.01/3.63 Q restricted rewrite system: 10.01/3.63 The TRS R consists of the following rules: 10.01/3.63 10.01/3.63 gcd(z, y) -> U1(iadd(z), y) 10.01/3.63 U1(tp2(x, y), y) -> gcd(x, y) 10.01/3.63 gcd(y, z) -> U2(iadd(z), y) 10.01/3.63 U2(tp2(x, y), y) -> gcd(x, y) 10.01/3.63 iadd(s(z)) -> U3(iadd(z)) 10.01/3.63 U3(tp2(x, y)) -> tp2(s(x), y) 10.01/3.63 iadd(y) -> tp2(0, y) 10.01/3.63 10.01/3.63 Q is empty. 10.01/3.63 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (5) DependencyPairsProof (EQUIVALENT) 10.01/3.63 Using Dependency Pairs [AG00,LPAR04] we result in the following initial DP problem. 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (6) 10.01/3.63 Obligation: 10.01/3.63 Q DP problem: 10.01/3.63 The TRS P consists of the following rules: 10.01/3.63 10.01/3.63 GCD(z, y) -> U1^1(iadd(z), y) 10.01/3.63 GCD(z, y) -> IADD(z) 10.01/3.63 U1^1(tp2(x, y), y) -> GCD(x, y) 10.01/3.63 GCD(y, z) -> U2^1(iadd(z), y) 10.01/3.63 GCD(y, z) -> IADD(z) 10.01/3.63 U2^1(tp2(x, y), y) -> GCD(x, y) 10.01/3.63 IADD(s(z)) -> U3^1(iadd(z)) 10.01/3.63 IADD(s(z)) -> IADD(z) 10.01/3.63 10.01/3.63 The TRS R consists of the following rules: 10.01/3.63 10.01/3.63 gcd(z, y) -> U1(iadd(z), y) 10.01/3.63 U1(tp2(x, y), y) -> gcd(x, y) 10.01/3.63 gcd(y, z) -> U2(iadd(z), y) 10.01/3.63 U2(tp2(x, y), y) -> gcd(x, y) 10.01/3.63 iadd(s(z)) -> U3(iadd(z)) 10.01/3.63 U3(tp2(x, y)) -> tp2(s(x), y) 10.01/3.63 iadd(y) -> tp2(0, y) 10.01/3.63 10.01/3.63 Q is empty. 10.01/3.63 We have to consider all minimal (P,Q,R)-chains. 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (7) DependencyGraphProof (EQUIVALENT) 10.01/3.63 The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 2 SCCs with 3 less nodes. 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (8) 10.01/3.63 Complex Obligation (AND) 10.01/3.63 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (9) 10.01/3.63 Obligation: 10.01/3.63 Q DP problem: 10.01/3.63 The TRS P consists of the following rules: 10.01/3.63 10.01/3.63 IADD(s(z)) -> IADD(z) 10.01/3.63 10.01/3.63 The TRS R consists of the following rules: 10.01/3.63 10.01/3.63 gcd(z, y) -> U1(iadd(z), y) 10.01/3.63 U1(tp2(x, y), y) -> gcd(x, y) 10.01/3.63 gcd(y, z) -> U2(iadd(z), y) 10.01/3.63 U2(tp2(x, y), y) -> gcd(x, y) 10.01/3.63 iadd(s(z)) -> U3(iadd(z)) 10.01/3.63 U3(tp2(x, y)) -> tp2(s(x), y) 10.01/3.63 iadd(y) -> tp2(0, y) 10.01/3.63 10.01/3.63 Q is empty. 10.01/3.63 We have to consider all minimal (P,Q,R)-chains. 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (10) UsableRulesProof (EQUIVALENT) 10.01/3.63 We can use the usable rules and reduction pair processor [LPAR04] with the Ce-compatible extension of the polynomial order that maps every function symbol to the sum of its arguments. Then, we can delete all non-usable rules [FROCOS05] from R. 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (11) 10.01/3.63 Obligation: 10.01/3.63 Q DP problem: 10.01/3.63 The TRS P consists of the following rules: 10.01/3.63 10.01/3.63 IADD(s(z)) -> IADD(z) 10.01/3.63 10.01/3.63 R is empty. 10.01/3.63 Q is empty. 10.01/3.63 We have to consider all minimal (P,Q,R)-chains. 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (12) QDPSizeChangeProof (EQUIVALENT) 10.01/3.63 By using the subterm criterion [SUBTERM_CRITERION] together with the size-change analysis [AAECC05] we have proven that there are no infinite chains for this DP problem. 10.01/3.63 10.01/3.63 From the DPs we obtained the following set of size-change graphs: 10.01/3.63 *IADD(s(z)) -> IADD(z) 10.01/3.63 The graph contains the following edges 1 > 1 10.01/3.63 10.01/3.63 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (13) 10.01/3.63 YES 10.01/3.63 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (14) 10.01/3.63 Obligation: 10.01/3.63 Q DP problem: 10.01/3.63 The TRS P consists of the following rules: 10.01/3.63 10.01/3.63 U1^1(tp2(x, y), y) -> GCD(x, y) 10.01/3.63 GCD(z, y) -> U1^1(iadd(z), y) 10.01/3.63 GCD(y, z) -> U2^1(iadd(z), y) 10.01/3.63 U2^1(tp2(x, y), y) -> GCD(x, y) 10.01/3.63 10.01/3.63 The TRS R consists of the following rules: 10.01/3.63 10.01/3.63 gcd(z, y) -> U1(iadd(z), y) 10.01/3.63 U1(tp2(x, y), y) -> gcd(x, y) 10.01/3.63 gcd(y, z) -> U2(iadd(z), y) 10.01/3.63 U2(tp2(x, y), y) -> gcd(x, y) 10.01/3.63 iadd(s(z)) -> U3(iadd(z)) 10.01/3.63 U3(tp2(x, y)) -> tp2(s(x), y) 10.01/3.63 iadd(y) -> tp2(0, y) 10.01/3.63 10.01/3.63 Q is empty. 10.01/3.63 We have to consider all minimal (P,Q,R)-chains. 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (15) UsableRulesProof (EQUIVALENT) 10.01/3.63 We can use the usable rules and reduction pair processor [LPAR04] with the Ce-compatible extension of the polynomial order that maps every function symbol to the sum of its arguments. Then, we can delete all non-usable rules [FROCOS05] from R. 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (16) 10.01/3.63 Obligation: 10.01/3.63 Q DP problem: 10.01/3.63 The TRS P consists of the following rules: 10.01/3.63 10.01/3.63 U1^1(tp2(x, y), y) -> GCD(x, y) 10.01/3.63 GCD(z, y) -> U1^1(iadd(z), y) 10.01/3.63 GCD(y, z) -> U2^1(iadd(z), y) 10.01/3.63 U2^1(tp2(x, y), y) -> GCD(x, y) 10.01/3.63 10.01/3.63 The TRS R consists of the following rules: 10.01/3.63 10.01/3.63 iadd(s(z)) -> U3(iadd(z)) 10.01/3.63 iadd(y) -> tp2(0, y) 10.01/3.63 U3(tp2(x, y)) -> tp2(s(x), y) 10.01/3.63 10.01/3.63 Q is empty. 10.01/3.63 We have to consider all minimal (P,Q,R)-chains. 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (17) TransformationProof (EQUIVALENT) 10.01/3.63 By narrowing [LPAR04] the rule GCD(z, y) -> U1^1(iadd(z), y) at position [0] we obtained the following new rules [LPAR04]: 10.01/3.63 10.01/3.63 (GCD(s(x0), y1) -> U1^1(U3(iadd(x0)), y1),GCD(s(x0), y1) -> U1^1(U3(iadd(x0)), y1)) 10.01/3.63 (GCD(x0, y1) -> U1^1(tp2(0, x0), y1),GCD(x0, y1) -> U1^1(tp2(0, x0), y1)) 10.01/3.63 10.01/3.63 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (18) 10.01/3.63 Obligation: 10.01/3.63 Q DP problem: 10.01/3.63 The TRS P consists of the following rules: 10.01/3.63 10.01/3.63 U1^1(tp2(x, y), y) -> GCD(x, y) 10.01/3.63 GCD(y, z) -> U2^1(iadd(z), y) 10.01/3.63 U2^1(tp2(x, y), y) -> GCD(x, y) 10.01/3.63 GCD(s(x0), y1) -> U1^1(U3(iadd(x0)), y1) 10.01/3.63 GCD(x0, y1) -> U1^1(tp2(0, x0), y1) 10.01/3.63 10.01/3.63 The TRS R consists of the following rules: 10.01/3.63 10.01/3.63 iadd(s(z)) -> U3(iadd(z)) 10.01/3.63 iadd(y) -> tp2(0, y) 10.01/3.63 U3(tp2(x, y)) -> tp2(s(x), y) 10.01/3.63 10.01/3.63 Q is empty. 10.01/3.63 We have to consider all minimal (P,Q,R)-chains. 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (19) TransformationProof (EQUIVALENT) 10.01/3.63 By narrowing [LPAR04] the rule GCD(y, z) -> U2^1(iadd(z), y) at position [0] we obtained the following new rules [LPAR04]: 10.01/3.63 10.01/3.63 (GCD(y0, s(x0)) -> U2^1(U3(iadd(x0)), y0),GCD(y0, s(x0)) -> U2^1(U3(iadd(x0)), y0)) 10.01/3.63 (GCD(y0, x0) -> U2^1(tp2(0, x0), y0),GCD(y0, x0) -> U2^1(tp2(0, x0), y0)) 10.01/3.63 10.01/3.63 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (20) 10.01/3.63 Obligation: 10.01/3.63 Q DP problem: 10.01/3.63 The TRS P consists of the following rules: 10.01/3.63 10.01/3.63 U1^1(tp2(x, y), y) -> GCD(x, y) 10.01/3.63 U2^1(tp2(x, y), y) -> GCD(x, y) 10.01/3.63 GCD(s(x0), y1) -> U1^1(U3(iadd(x0)), y1) 10.01/3.63 GCD(x0, y1) -> U1^1(tp2(0, x0), y1) 10.01/3.63 GCD(y0, s(x0)) -> U2^1(U3(iadd(x0)), y0) 10.01/3.63 GCD(y0, x0) -> U2^1(tp2(0, x0), y0) 10.01/3.63 10.01/3.63 The TRS R consists of the following rules: 10.01/3.63 10.01/3.63 iadd(s(z)) -> U3(iadd(z)) 10.01/3.63 iadd(y) -> tp2(0, y) 10.01/3.63 U3(tp2(x, y)) -> tp2(s(x), y) 10.01/3.63 10.01/3.63 Q is empty. 10.01/3.63 We have to consider all minimal (P,Q,R)-chains. 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (21) MRRProof (EQUIVALENT) 10.01/3.63 By using the rule removal processor [LPAR04] with the following ordering, at least one Dependency Pair or term rewrite system rule of this QDP problem can be strictly oriented. 10.01/3.63 10.01/3.63 Strictly oriented dependency pairs: 10.01/3.63 10.01/3.63 GCD(y0, s(x0)) -> U2^1(U3(iadd(x0)), y0) 10.01/3.63 10.01/3.63 10.01/3.63 Used ordering: Polynomial interpretation [POLO]: 10.01/3.63 10.01/3.63 POL(0) = 0 10.01/3.63 POL(GCD(x_1, x_2)) = x_1 + 2*x_2 10.01/3.63 POL(U1^1(x_1, x_2)) = x_1 + 2*x_2 10.01/3.63 POL(U2^1(x_1, x_2)) = x_1 + x_2 10.01/3.63 POL(U3(x_1)) = 2 + 2*x_1 10.01/3.63 POL(iadd(x_1)) = x_1 10.01/3.63 POL(s(x_1)) = 2 + 2*x_1 10.01/3.63 POL(tp2(x_1, x_2)) = x_1 + x_2 10.01/3.63 10.01/3.63 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (22) 10.01/3.63 Obligation: 10.01/3.63 Q DP problem: 10.01/3.63 The TRS P consists of the following rules: 10.01/3.63 10.01/3.63 U1^1(tp2(x, y), y) -> GCD(x, y) 10.01/3.63 U2^1(tp2(x, y), y) -> GCD(x, y) 10.01/3.63 GCD(s(x0), y1) -> U1^1(U3(iadd(x0)), y1) 10.01/3.63 GCD(x0, y1) -> U1^1(tp2(0, x0), y1) 10.01/3.63 GCD(y0, x0) -> U2^1(tp2(0, x0), y0) 10.01/3.63 10.01/3.63 The TRS R consists of the following rules: 10.01/3.63 10.01/3.63 iadd(s(z)) -> U3(iadd(z)) 10.01/3.63 iadd(y) -> tp2(0, y) 10.01/3.63 U3(tp2(x, y)) -> tp2(s(x), y) 10.01/3.63 10.01/3.63 Q is empty. 10.01/3.63 We have to consider all minimal (P,Q,R)-chains. 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (23) TransformationProof (EQUIVALENT) 10.01/3.63 By instantiating [LPAR04] the rule U2^1(tp2(x, y), y) -> GCD(x, y) we obtained the following new rules [LPAR04]: 10.01/3.63 10.01/3.63 (U2^1(tp2(0, y_0), y_0) -> GCD(0, y_0),U2^1(tp2(0, y_0), y_0) -> GCD(0, y_0)) 10.01/3.63 10.01/3.63 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (24) 10.01/3.63 Obligation: 10.01/3.63 Q DP problem: 10.01/3.63 The TRS P consists of the following rules: 10.01/3.63 10.01/3.63 U1^1(tp2(x, y), y) -> GCD(x, y) 10.01/3.63 GCD(s(x0), y1) -> U1^1(U3(iadd(x0)), y1) 10.01/3.63 GCD(x0, y1) -> U1^1(tp2(0, x0), y1) 10.01/3.63 GCD(y0, x0) -> U2^1(tp2(0, x0), y0) 10.01/3.63 U2^1(tp2(0, y_0), y_0) -> GCD(0, y_0) 10.01/3.63 10.01/3.63 The TRS R consists of the following rules: 10.01/3.63 10.01/3.63 iadd(s(z)) -> U3(iadd(z)) 10.01/3.63 iadd(y) -> tp2(0, y) 10.01/3.63 U3(tp2(x, y)) -> tp2(s(x), y) 10.01/3.63 10.01/3.63 Q is empty. 10.01/3.63 We have to consider all minimal (P,Q,R)-chains. 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (25) NonTerminationLoopProof (COMPLETE) 10.01/3.63 We used the non-termination processor [FROCOS05] to show that the DP problem is infinite. 10.01/3.63 Found a loop by narrowing to the right: 10.01/3.63 10.01/3.63 s = U1^1(tp2(x0, y1), y1) evaluates to t =U1^1(tp2(0, x0), y1) 10.01/3.63 10.01/3.63 Thus s starts an infinite chain as s semiunifies with t with the following substitutions: 10.01/3.63 * Matcher: [ ] 10.01/3.63 * Semiunifier: [x0 / 0, y1 / 0] 10.01/3.63 10.01/3.63 -------------------------------------------------------------------------------- 10.01/3.63 Rewriting sequence 10.01/3.63 10.01/3.63 U1^1(tp2(0, 0), 0) -> GCD(0, 0) 10.01/3.63 with rule U1^1(tp2(x, y), y) -> GCD(x, y) and matcher [x / 0, y / 0]. 10.01/3.63 10.01/3.63 GCD(0, 0) -> U1^1(tp2(0, 0), 0) 10.01/3.63 with rule GCD(x0, y1) -> U1^1(tp2(0, x0), y1) at position [] and matcher [x0 / 0, y1 / 0] 10.01/3.63 10.01/3.63 Now applying the matcher to the start term leads to a term which is equal to the last term in the rewriting sequence 10.01/3.63 10.01/3.63 10.01/3.63 All these steps are and every following step will be a correct step w.r.t to Q. 10.01/3.63 10.01/3.63 10.01/3.63 10.01/3.63 10.01/3.63 ---------------------------------------- 10.01/3.63 10.01/3.63 (26) 10.01/3.63 NO 10.25/3.71 EOF