3.32/1.73 YES 3.32/1.75 We consider the system theBenchmark. 3.32/1.75 3.32/1.75 Alphabet: 3.32/1.75 3.32/1.75 0 : [] --> a 3.32/1.75 cons : [c * d] --> d 3.32/1.75 false : [] --> b 3.32/1.75 filter : [c -> b * d] --> d 3.32/1.75 filter2 : [b * c -> b * c * d] --> d 3.32/1.75 map : [c -> c * d] --> d 3.32/1.75 minus : [a * a] --> a 3.32/1.75 nil : [] --> d 3.32/1.75 plus : [a * a] --> a 3.32/1.75 quot : [a * a] --> a 3.32/1.75 s : [a] --> a 3.32/1.75 true : [] --> b 3.32/1.75 3.32/1.75 Rules: 3.32/1.75 3.32/1.75 minus(x, 0) => x 3.32/1.75 minus(s(x), s(y)) => minus(x, y) 3.32/1.75 quot(0, s(x)) => 0 3.32/1.75 quot(s(x), s(y)) => s(quot(minus(x, y), s(y))) 3.32/1.75 plus(0, x) => x 3.32/1.75 plus(s(x), y) => s(plus(x, y)) 3.32/1.75 plus(minus(x, s(0)), minus(y, s(s(z)))) => plus(minus(y, s(s(z))), minus(x, s(0))) 3.32/1.75 plus(plus(x, s(0)), plus(y, s(s(z)))) => plus(plus(y, s(s(z))), plus(x, s(0))) 3.32/1.75 map(f, nil) => nil 3.32/1.75 map(f, cons(x, y)) => cons(f x, map(f, y)) 3.32/1.75 filter(f, nil) => nil 3.32/1.75 filter(f, cons(x, y)) => filter2(f x, f, x, y) 3.32/1.75 filter2(true, f, x, y) => cons(x, filter(f, y)) 3.32/1.75 filter2(false, f, x, y) => filter(f, y) 3.32/1.75 3.32/1.75 This AFS is converted to an AFSM simply by replacing all free variables by meta-variables (with arity 0). 3.32/1.75 3.32/1.75 We observe that the rules contain a first-order subset: 3.32/1.75 3.32/1.75 minus(X, 0) => X 3.32/1.75 minus(s(X), s(Y)) => minus(X, Y) 3.32/1.75 quot(0, s(X)) => 0 3.32/1.75 quot(s(X), s(Y)) => s(quot(minus(X, Y), s(Y))) 3.32/1.75 plus(0, X) => X 3.32/1.75 plus(s(X), Y) => s(plus(X, Y)) 3.32/1.75 plus(minus(X, s(0)), minus(Y, s(s(Z)))) => plus(minus(Y, s(s(Z))), minus(X, s(0))) 3.32/1.75 plus(plus(X, s(0)), plus(Y, s(s(Z)))) => plus(plus(Y, s(s(Z))), plus(X, s(0))) 3.32/1.75 3.32/1.75 Moreover, the system is finitely branching. Thus, by [Kop12, Thm. 7.55], we may omit all first-order dependency pairs from the dependency pair problem (DP(R), R) if this first-order part is Ce-terminating when seen as a many-sorted first-order TRS. 3.32/1.75 3.32/1.75 According to the external first-order termination prover, this system is indeed Ce-terminating: 3.32/1.75 3.32/1.75 || proof of resources/system.trs 3.32/1.75 || # AProVE Commit ID: d84c10301d352dfd14de2104819581f4682260f5 fuhs 20130616 3.32/1.75 || 3.32/1.75 || 3.32/1.75 || Termination w.r.t. Q of the given QTRS could be proven: 3.32/1.75 || 3.32/1.75 || (0) QTRS 3.32/1.75 || (1) DependencyPairsProof [EQUIVALENT] 3.32/1.75 || (2) QDP 3.32/1.75 || (3) DependencyGraphProof [EQUIVALENT] 3.32/1.75 || (4) AND 3.32/1.75 || (5) QDP 3.32/1.75 || (6) UsableRulesProof [EQUIVALENT] 3.32/1.75 || (7) QDP 3.32/1.75 || (8) MRRProof [EQUIVALENT] 3.32/1.75 || (9) QDP 3.32/1.75 || (10) MRRProof [EQUIVALENT] 3.32/1.75 || (11) QDP 3.32/1.75 || (12) MRRProof [EQUIVALENT] 3.32/1.75 || (13) QDP 3.32/1.75 || (14) DependencyGraphProof [EQUIVALENT] 3.32/1.75 || (15) TRUE 3.32/1.75 || (16) QDP 3.32/1.75 || (17) UsableRulesProof [EQUIVALENT] 3.32/1.75 || (18) QDP 3.32/1.75 || (19) QDPSizeChangeProof [EQUIVALENT] 3.32/1.75 || (20) YES 3.32/1.75 || (21) QDP 3.32/1.75 || (22) QDPOrderProof [EQUIVALENT] 3.32/1.75 || (23) QDP 3.32/1.75 || (24) PisEmptyProof [EQUIVALENT] 3.32/1.75 || (25) YES 3.32/1.75 || 3.32/1.75 || 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (0) 3.32/1.75 || Obligation: 3.32/1.75 || Q restricted rewrite system: 3.32/1.75 || The TRS R consists of the following rules: 3.32/1.75 || 3.32/1.75 || minus(%X, 0) -> %X 3.32/1.75 || minus(s(%X), s(%Y)) -> minus(%X, %Y) 3.32/1.75 || quot(0, s(%X)) -> 0 3.32/1.75 || quot(s(%X), s(%Y)) -> s(quot(minus(%X, %Y), s(%Y))) 3.32/1.75 || plus(0, %X) -> %X 3.32/1.75 || plus(s(%X), %Y) -> s(plus(%X, %Y)) 3.32/1.75 || plus(minus(%X, s(0)), minus(%Y, s(s(%Z)))) -> plus(minus(%Y, s(s(%Z))), minus(%X, s(0))) 3.32/1.75 || plus(plus(%X, s(0)), plus(%Y, s(s(%Z)))) -> plus(plus(%Y, s(s(%Z))), plus(%X, s(0))) 3.32/1.75 || ~PAIR(%X, %Y) -> %X 3.32/1.75 || ~PAIR(%X, %Y) -> %Y 3.32/1.75 || 3.32/1.75 || Q is empty. 3.32/1.75 || 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (1) DependencyPairsProof (EQUIVALENT) 3.32/1.75 || Using Dependency Pairs [AG00,LPAR04] we result in the following initial DP problem. 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (2) 3.32/1.75 || Obligation: 3.32/1.75 || Q DP problem: 3.32/1.75 || The TRS P consists of the following rules: 3.32/1.75 || 3.32/1.75 || MINUS(s(%X), s(%Y)) -> MINUS(%X, %Y) 3.32/1.75 || QUOT(s(%X), s(%Y)) -> QUOT(minus(%X, %Y), s(%Y)) 3.32/1.75 || QUOT(s(%X), s(%Y)) -> MINUS(%X, %Y) 3.32/1.75 || PLUS(s(%X), %Y) -> PLUS(%X, %Y) 3.32/1.75 || PLUS(minus(%X, s(0)), minus(%Y, s(s(%Z)))) -> PLUS(minus(%Y, s(s(%Z))), minus(%X, s(0))) 3.32/1.75 || PLUS(plus(%X, s(0)), plus(%Y, s(s(%Z)))) -> PLUS(plus(%Y, s(s(%Z))), plus(%X, s(0))) 3.32/1.75 || 3.32/1.75 || The TRS R consists of the following rules: 3.32/1.75 || 3.32/1.75 || minus(%X, 0) -> %X 3.32/1.75 || minus(s(%X), s(%Y)) -> minus(%X, %Y) 3.32/1.75 || quot(0, s(%X)) -> 0 3.32/1.75 || quot(s(%X), s(%Y)) -> s(quot(minus(%X, %Y), s(%Y))) 3.32/1.75 || plus(0, %X) -> %X 3.32/1.75 || plus(s(%X), %Y) -> s(plus(%X, %Y)) 3.32/1.75 || plus(minus(%X, s(0)), minus(%Y, s(s(%Z)))) -> plus(minus(%Y, s(s(%Z))), minus(%X, s(0))) 3.32/1.75 || plus(plus(%X, s(0)), plus(%Y, s(s(%Z)))) -> plus(plus(%Y, s(s(%Z))), plus(%X, s(0))) 3.32/1.75 || ~PAIR(%X, %Y) -> %X 3.32/1.75 || ~PAIR(%X, %Y) -> %Y 3.32/1.75 || 3.32/1.75 || Q is empty. 3.32/1.75 || We have to consider all minimal (P,Q,R)-chains. 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (3) DependencyGraphProof (EQUIVALENT) 3.32/1.75 || The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 3 SCCs with 1 less node. 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (4) 3.32/1.75 || Complex Obligation (AND) 3.32/1.75 || 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (5) 3.32/1.75 || Obligation: 3.32/1.75 || Q DP problem: 3.32/1.75 || The TRS P consists of the following rules: 3.32/1.75 || 3.32/1.75 || PLUS(minus(%X, s(0)), minus(%Y, s(s(%Z)))) -> PLUS(minus(%Y, s(s(%Z))), minus(%X, s(0))) 3.32/1.75 || PLUS(s(%X), %Y) -> PLUS(%X, %Y) 3.32/1.75 || PLUS(plus(%X, s(0)), plus(%Y, s(s(%Z)))) -> PLUS(plus(%Y, s(s(%Z))), plus(%X, s(0))) 3.32/1.75 || 3.32/1.75 || The TRS R consists of the following rules: 3.32/1.75 || 3.32/1.75 || minus(%X, 0) -> %X 3.32/1.75 || minus(s(%X), s(%Y)) -> minus(%X, %Y) 3.32/1.75 || quot(0, s(%X)) -> 0 3.32/1.75 || quot(s(%X), s(%Y)) -> s(quot(minus(%X, %Y), s(%Y))) 3.32/1.75 || plus(0, %X) -> %X 3.32/1.75 || plus(s(%X), %Y) -> s(plus(%X, %Y)) 3.32/1.75 || plus(minus(%X, s(0)), minus(%Y, s(s(%Z)))) -> plus(minus(%Y, s(s(%Z))), minus(%X, s(0))) 3.32/1.75 || plus(plus(%X, s(0)), plus(%Y, s(s(%Z)))) -> plus(plus(%Y, s(s(%Z))), plus(%X, s(0))) 3.32/1.75 || ~PAIR(%X, %Y) -> %X 3.32/1.75 || ~PAIR(%X, %Y) -> %Y 3.32/1.75 || 3.32/1.75 || Q is empty. 3.32/1.75 || We have to consider all minimal (P,Q,R)-chains. 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (6) UsableRulesProof (EQUIVALENT) 3.32/1.75 || 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. 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (7) 3.32/1.75 || Obligation: 3.32/1.75 || Q DP problem: 3.32/1.75 || The TRS P consists of the following rules: 3.32/1.75 || 3.32/1.75 || PLUS(minus(%X, s(0)), minus(%Y, s(s(%Z)))) -> PLUS(minus(%Y, s(s(%Z))), minus(%X, s(0))) 3.32/1.75 || PLUS(s(%X), %Y) -> PLUS(%X, %Y) 3.32/1.75 || PLUS(plus(%X, s(0)), plus(%Y, s(s(%Z)))) -> PLUS(plus(%Y, s(s(%Z))), plus(%X, s(0))) 3.32/1.75 || 3.32/1.75 || The TRS R consists of the following rules: 3.32/1.75 || 3.32/1.75 || plus(0, %X) -> %X 3.32/1.75 || plus(s(%X), %Y) -> s(plus(%X, %Y)) 3.32/1.75 || plus(plus(%X, s(0)), plus(%Y, s(s(%Z)))) -> plus(plus(%Y, s(s(%Z))), plus(%X, s(0))) 3.32/1.75 || plus(minus(%X, s(0)), minus(%Y, s(s(%Z)))) -> plus(minus(%Y, s(s(%Z))), minus(%X, s(0))) 3.32/1.75 || minus(s(%X), s(%Y)) -> minus(%X, %Y) 3.32/1.75 || minus(%X, 0) -> %X 3.32/1.75 || 3.32/1.75 || Q is empty. 3.32/1.75 || We have to consider all minimal (P,Q,R)-chains. 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (8) MRRProof (EQUIVALENT) 3.32/1.75 || 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. 3.32/1.75 || 3.32/1.75 || 3.32/1.75 || Strictly oriented rules of the TRS R: 3.32/1.75 || 3.32/1.75 || minus(%X, 0) -> %X 3.32/1.75 || 3.32/1.75 || Used ordering: Polynomial interpretation [POLO]: 3.32/1.75 || 3.32/1.75 || POL(0) = 0 3.32/1.75 || POL(PLUS(x_1, x_2)) = 2*x_1 + 2*x_2 3.32/1.75 || POL(minus(x_1, x_2)) = 2 + x_1 + x_2 3.32/1.75 || POL(plus(x_1, x_2)) = x_1 + x_2 3.32/1.75 || POL(s(x_1)) = x_1 3.32/1.75 || 3.32/1.75 || 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (9) 3.32/1.75 || Obligation: 3.32/1.75 || Q DP problem: 3.32/1.75 || The TRS P consists of the following rules: 3.32/1.75 || 3.32/1.75 || PLUS(minus(%X, s(0)), minus(%Y, s(s(%Z)))) -> PLUS(minus(%Y, s(s(%Z))), minus(%X, s(0))) 3.32/1.75 || PLUS(s(%X), %Y) -> PLUS(%X, %Y) 3.32/1.75 || PLUS(plus(%X, s(0)), plus(%Y, s(s(%Z)))) -> PLUS(plus(%Y, s(s(%Z))), plus(%X, s(0))) 3.32/1.75 || 3.32/1.75 || The TRS R consists of the following rules: 3.32/1.75 || 3.32/1.75 || plus(0, %X) -> %X 3.32/1.75 || plus(s(%X), %Y) -> s(plus(%X, %Y)) 3.32/1.75 || plus(plus(%X, s(0)), plus(%Y, s(s(%Z)))) -> plus(plus(%Y, s(s(%Z))), plus(%X, s(0))) 3.32/1.75 || plus(minus(%X, s(0)), minus(%Y, s(s(%Z)))) -> plus(minus(%Y, s(s(%Z))), minus(%X, s(0))) 3.32/1.75 || minus(s(%X), s(%Y)) -> minus(%X, %Y) 3.32/1.75 || 3.32/1.75 || Q is empty. 3.32/1.75 || We have to consider all minimal (P,Q,R)-chains. 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (10) MRRProof (EQUIVALENT) 3.32/1.75 || 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. 3.32/1.75 || 3.32/1.75 || 3.32/1.75 || Strictly oriented rules of the TRS R: 3.32/1.75 || 3.32/1.75 || plus(0, %X) -> %X 3.32/1.75 || 3.32/1.75 || Used ordering: Polynomial interpretation [POLO]: 3.32/1.75 || 3.32/1.75 || POL(0) = 0 3.32/1.75 || POL(PLUS(x_1, x_2)) = x_1 + x_2 3.32/1.75 || POL(minus(x_1, x_2)) = 2*x_1 + 2*x_2 3.32/1.75 || POL(plus(x_1, x_2)) = 2 + 2*x_1 + 2*x_2 3.32/1.75 || POL(s(x_1)) = x_1 3.32/1.75 || 3.32/1.75 || 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (11) 3.32/1.75 || Obligation: 3.32/1.75 || Q DP problem: 3.32/1.75 || The TRS P consists of the following rules: 3.32/1.75 || 3.32/1.75 || PLUS(minus(%X, s(0)), minus(%Y, s(s(%Z)))) -> PLUS(minus(%Y, s(s(%Z))), minus(%X, s(0))) 3.32/1.75 || PLUS(s(%X), %Y) -> PLUS(%X, %Y) 3.32/1.75 || PLUS(plus(%X, s(0)), plus(%Y, s(s(%Z)))) -> PLUS(plus(%Y, s(s(%Z))), plus(%X, s(0))) 3.32/1.75 || 3.32/1.75 || The TRS R consists of the following rules: 3.32/1.75 || 3.32/1.75 || plus(s(%X), %Y) -> s(plus(%X, %Y)) 3.32/1.75 || plus(plus(%X, s(0)), plus(%Y, s(s(%Z)))) -> plus(plus(%Y, s(s(%Z))), plus(%X, s(0))) 3.32/1.75 || plus(minus(%X, s(0)), minus(%Y, s(s(%Z)))) -> plus(minus(%Y, s(s(%Z))), minus(%X, s(0))) 3.32/1.75 || minus(s(%X), s(%Y)) -> minus(%X, %Y) 3.32/1.75 || 3.32/1.75 || Q is empty. 3.32/1.75 || We have to consider all minimal (P,Q,R)-chains. 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (12) MRRProof (EQUIVALENT) 3.32/1.75 || 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. 3.32/1.75 || 3.32/1.75 || Strictly oriented dependency pairs: 3.32/1.75 || 3.32/1.75 || PLUS(s(%X), %Y) -> PLUS(%X, %Y) 3.32/1.75 || 3.32/1.75 || Strictly oriented rules of the TRS R: 3.32/1.75 || 3.32/1.75 || minus(s(%X), s(%Y)) -> minus(%X, %Y) 3.32/1.75 || 3.32/1.75 || Used ordering: Polynomial interpretation [POLO]: 3.32/1.75 || 3.32/1.75 || POL(0) = 0 3.32/1.75 || POL(PLUS(x_1, x_2)) = 2*x_1 + 2*x_2 3.32/1.75 || POL(minus(x_1, x_2)) = 2*x_1 + 2*x_2 3.32/1.75 || POL(plus(x_1, x_2)) = x_1 + x_2 3.32/1.75 || POL(s(x_1)) = 1 + x_1 3.32/1.75 || 3.32/1.75 || 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (13) 3.32/1.75 || Obligation: 3.32/1.75 || Q DP problem: 3.32/1.75 || The TRS P consists of the following rules: 3.32/1.75 || 3.32/1.75 || PLUS(minus(%X, s(0)), minus(%Y, s(s(%Z)))) -> PLUS(minus(%Y, s(s(%Z))), minus(%X, s(0))) 3.32/1.75 || PLUS(plus(%X, s(0)), plus(%Y, s(s(%Z)))) -> PLUS(plus(%Y, s(s(%Z))), plus(%X, s(0))) 3.32/1.75 || 3.32/1.75 || The TRS R consists of the following rules: 3.32/1.75 || 3.32/1.75 || plus(s(%X), %Y) -> s(plus(%X, %Y)) 3.32/1.75 || plus(plus(%X, s(0)), plus(%Y, s(s(%Z)))) -> plus(plus(%Y, s(s(%Z))), plus(%X, s(0))) 3.32/1.75 || plus(minus(%X, s(0)), minus(%Y, s(s(%Z)))) -> plus(minus(%Y, s(s(%Z))), minus(%X, s(0))) 3.32/1.75 || 3.32/1.75 || Q is empty. 3.32/1.75 || We have to consider all minimal (P,Q,R)-chains. 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (14) DependencyGraphProof (EQUIVALENT) 3.32/1.75 || The approximation of the Dependency Graph [LPAR04,FROCOS05,EDGSTAR] contains 0 SCCs with 2 less nodes. 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (15) 3.32/1.75 || TRUE 3.32/1.75 || 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (16) 3.32/1.75 || Obligation: 3.32/1.75 || Q DP problem: 3.32/1.75 || The TRS P consists of the following rules: 3.32/1.75 || 3.32/1.75 || MINUS(s(%X), s(%Y)) -> MINUS(%X, %Y) 3.32/1.75 || 3.32/1.75 || The TRS R consists of the following rules: 3.32/1.75 || 3.32/1.75 || minus(%X, 0) -> %X 3.32/1.75 || minus(s(%X), s(%Y)) -> minus(%X, %Y) 3.32/1.75 || quot(0, s(%X)) -> 0 3.32/1.75 || quot(s(%X), s(%Y)) -> s(quot(minus(%X, %Y), s(%Y))) 3.32/1.75 || plus(0, %X) -> %X 3.32/1.75 || plus(s(%X), %Y) -> s(plus(%X, %Y)) 3.32/1.75 || plus(minus(%X, s(0)), minus(%Y, s(s(%Z)))) -> plus(minus(%Y, s(s(%Z))), minus(%X, s(0))) 3.32/1.75 || plus(plus(%X, s(0)), plus(%Y, s(s(%Z)))) -> plus(plus(%Y, s(s(%Z))), plus(%X, s(0))) 3.32/1.75 || ~PAIR(%X, %Y) -> %X 3.32/1.75 || ~PAIR(%X, %Y) -> %Y 3.32/1.75 || 3.32/1.75 || Q is empty. 3.32/1.75 || We have to consider all minimal (P,Q,R)-chains. 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (17) UsableRulesProof (EQUIVALENT) 3.32/1.75 || 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. 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (18) 3.32/1.75 || Obligation: 3.32/1.75 || Q DP problem: 3.32/1.75 || The TRS P consists of the following rules: 3.32/1.75 || 3.32/1.75 || MINUS(s(%X), s(%Y)) -> MINUS(%X, %Y) 3.32/1.75 || 3.32/1.75 || R is empty. 3.32/1.75 || Q is empty. 3.32/1.75 || We have to consider all minimal (P,Q,R)-chains. 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (19) QDPSizeChangeProof (EQUIVALENT) 3.32/1.75 || 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. 3.32/1.75 || 3.32/1.75 || From the DPs we obtained the following set of size-change graphs: 3.32/1.75 || *MINUS(s(%X), s(%Y)) -> MINUS(%X, %Y) 3.32/1.75 || The graph contains the following edges 1 > 1, 2 > 2 3.32/1.75 || 3.32/1.75 || 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (20) 3.32/1.75 || YES 3.32/1.75 || 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (21) 3.32/1.75 || Obligation: 3.32/1.75 || Q DP problem: 3.32/1.75 || The TRS P consists of the following rules: 3.32/1.75 || 3.32/1.75 || QUOT(s(%X), s(%Y)) -> QUOT(minus(%X, %Y), s(%Y)) 3.32/1.75 || 3.32/1.75 || The TRS R consists of the following rules: 3.32/1.75 || 3.32/1.75 || minus(%X, 0) -> %X 3.32/1.75 || minus(s(%X), s(%Y)) -> minus(%X, %Y) 3.32/1.75 || quot(0, s(%X)) -> 0 3.32/1.75 || quot(s(%X), s(%Y)) -> s(quot(minus(%X, %Y), s(%Y))) 3.32/1.75 || plus(0, %X) -> %X 3.32/1.75 || plus(s(%X), %Y) -> s(plus(%X, %Y)) 3.32/1.75 || plus(minus(%X, s(0)), minus(%Y, s(s(%Z)))) -> plus(minus(%Y, s(s(%Z))), minus(%X, s(0))) 3.32/1.75 || plus(plus(%X, s(0)), plus(%Y, s(s(%Z)))) -> plus(plus(%Y, s(s(%Z))), plus(%X, s(0))) 3.32/1.75 || ~PAIR(%X, %Y) -> %X 3.32/1.75 || ~PAIR(%X, %Y) -> %Y 3.32/1.75 || 3.32/1.75 || Q is empty. 3.32/1.75 || We have to consider all minimal (P,Q,R)-chains. 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (22) QDPOrderProof (EQUIVALENT) 3.32/1.75 || We use the reduction pair processor [LPAR04,JAR06]. 3.32/1.75 || 3.32/1.75 || 3.32/1.75 || The following pairs can be oriented strictly and are deleted. 3.32/1.75 || 3.32/1.75 || QUOT(s(%X), s(%Y)) -> QUOT(minus(%X, %Y), s(%Y)) 3.32/1.75 || The remaining pairs can at least be oriented weakly. 3.32/1.75 || Used ordering: Polynomial interpretation [POLO]: 3.32/1.75 || 3.32/1.75 || POL(0) = 0 3.32/1.75 || POL(QUOT(x_1, x_2)) = x_1 3.32/1.75 || POL(minus(x_1, x_2)) = x_1 3.32/1.75 || POL(s(x_1)) = 1 + x_1 3.32/1.75 || 3.32/1.75 || The following usable rules [FROCOS05] with respect to the argument filtering of the ordering [JAR06] were oriented: 3.32/1.75 || 3.32/1.75 || minus(%X, 0) -> %X 3.32/1.75 || minus(s(%X), s(%Y)) -> minus(%X, %Y) 3.32/1.75 || 3.32/1.75 || 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (23) 3.32/1.75 || Obligation: 3.32/1.75 || Q DP problem: 3.32/1.75 || P is empty. 3.32/1.75 || The TRS R consists of the following rules: 3.32/1.75 || 3.32/1.75 || minus(%X, 0) -> %X 3.32/1.75 || minus(s(%X), s(%Y)) -> minus(%X, %Y) 3.32/1.75 || quot(0, s(%X)) -> 0 3.32/1.75 || quot(s(%X), s(%Y)) -> s(quot(minus(%X, %Y), s(%Y))) 3.32/1.75 || plus(0, %X) -> %X 3.32/1.75 || plus(s(%X), %Y) -> s(plus(%X, %Y)) 3.32/1.75 || plus(minus(%X, s(0)), minus(%Y, s(s(%Z)))) -> plus(minus(%Y, s(s(%Z))), minus(%X, s(0))) 3.32/1.75 || plus(plus(%X, s(0)), plus(%Y, s(s(%Z)))) -> plus(plus(%Y, s(s(%Z))), plus(%X, s(0))) 3.32/1.75 || ~PAIR(%X, %Y) -> %X 3.32/1.75 || ~PAIR(%X, %Y) -> %Y 3.32/1.75 || 3.32/1.75 || Q is empty. 3.32/1.75 || We have to consider all minimal (P,Q,R)-chains. 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (24) PisEmptyProof (EQUIVALENT) 3.32/1.75 || The TRS P is empty. Hence, there is no (P,Q,R) chain. 3.32/1.75 || ---------------------------------------- 3.32/1.75 || 3.32/1.75 || (25) 3.32/1.75 || YES 3.32/1.75 || 3.32/1.75 We use the dependency pair framework as described in [Kop12, Ch. 6/7], with static dependency pairs (see [KusIsoSakBla09] and the adaptation for AFSMs and accessible arguments in [Kop13]). 3.32/1.75 3.32/1.75 We thus obtain the following dependency pair problem (P_0, R_0, static, formative): 3.32/1.75 3.32/1.75 Dependency Pairs P_0: 3.32/1.75 3.32/1.75 0] map#(F, cons(X, Y)) =#> map#(F, Y) 3.32/1.75 1] filter#(F, cons(X, Y)) =#> filter2#(F X, F, X, Y) 3.32/1.75 2] filter2#(true, F, X, Y) =#> filter#(F, Y) 3.32/1.75 3] filter2#(false, F, X, Y) =#> filter#(F, Y) 3.32/1.75 3.32/1.75 Rules R_0: 3.32/1.75 3.32/1.75 minus(X, 0) => X 3.32/1.75 minus(s(X), s(Y)) => minus(X, Y) 3.32/1.75 quot(0, s(X)) => 0 3.32/1.75 quot(s(X), s(Y)) => s(quot(minus(X, Y), s(Y))) 3.32/1.75 plus(0, X) => X 3.32/1.75 plus(s(X), Y) => s(plus(X, Y)) 3.32/1.75 plus(minus(X, s(0)), minus(Y, s(s(Z)))) => plus(minus(Y, s(s(Z))), minus(X, s(0))) 3.32/1.75 plus(plus(X, s(0)), plus(Y, s(s(Z)))) => plus(plus(Y, s(s(Z))), plus(X, s(0))) 3.32/1.75 map(F, nil) => nil 3.32/1.75 map(F, cons(X, Y)) => cons(F X, map(F, Y)) 3.32/1.75 filter(F, nil) => nil 3.32/1.75 filter(F, cons(X, Y)) => filter2(F X, F, X, Y) 3.32/1.75 filter2(true, F, X, Y) => cons(X, filter(F, Y)) 3.32/1.75 filter2(false, F, X, Y) => filter(F, Y) 3.32/1.75 3.32/1.75 Thus, the original system is terminating if (P_0, R_0, static, formative) is finite. 3.32/1.75 3.32/1.75 We consider the dependency pair problem (P_0, R_0, static, formative). 3.32/1.75 3.32/1.75 We place the elements of P in a dependency graph approximation G (see e.g. [Kop12, Thm. 7.27, 7.29], as follows: 3.32/1.75 3.32/1.75 * 0 : 0 3.32/1.75 * 1 : 2, 3 3.32/1.75 * 2 : 1 3.32/1.75 * 3 : 1 3.32/1.75 3.32/1.75 This graph has the following strongly connected components: 3.32/1.75 3.32/1.75 P_1: 3.32/1.75 3.32/1.75 map#(F, cons(X, Y)) =#> map#(F, Y) 3.32/1.75 3.32/1.75 P_2: 3.32/1.75 3.32/1.75 filter#(F, cons(X, Y)) =#> filter2#(F X, F, X, Y) 3.32/1.75 filter2#(true, F, X, Y) =#> filter#(F, Y) 3.32/1.75 filter2#(false, F, X, Y) =#> filter#(F, Y) 3.32/1.75 3.32/1.75 By [Kop12, Thm. 7.31], we may replace any dependency pair problem (P_0, R_0, m, f) by (P_1, R_0, m, f) and (P_2, R_0, m, f). 3.32/1.75 3.32/1.75 Thus, the original system is terminating if each of (P_1, R_0, static, formative) and (P_2, R_0, static, formative) is finite. 3.32/1.75 3.32/1.75 We consider the dependency pair problem (P_2, R_0, static, formative). 3.32/1.75 3.32/1.75 We apply the subterm criterion with the following projection function: 3.32/1.75 3.32/1.75 nu(filter2#) = 4 3.32/1.75 nu(filter#) = 2 3.32/1.75 3.32/1.75 Thus, we can orient the dependency pairs as follows: 3.32/1.75 3.32/1.75 nu(filter#(F, cons(X, Y))) = cons(X, Y) |> Y = nu(filter2#(F X, F, X, Y)) 3.32/1.75 nu(filter2#(true, F, X, Y)) = Y = Y = nu(filter#(F, Y)) 3.32/1.75 nu(filter2#(false, F, X, Y)) = Y = Y = nu(filter#(F, Y)) 3.32/1.75 3.32/1.75 By [Kop12, Thm. 7.35] and [Kop13, Thm. 5], we may replace a dependency pair problem (P_2, R_0, static, f) by (P_3, R_0, static, f), where P_3 contains: 3.32/1.75 3.32/1.75 filter2#(true, F, X, Y) =#> filter#(F, Y) 3.32/1.75 filter2#(false, F, X, Y) =#> filter#(F, Y) 3.32/1.75 3.32/1.75 Thus, the original system is terminating if each of (P_1, R_0, static, formative) and (P_3, R_0, static, formative) is finite. 3.32/1.75 3.32/1.75 We consider the dependency pair problem (P_3, R_0, static, formative). 3.32/1.75 3.32/1.75 We place the elements of P in a dependency graph approximation G (see e.g. [Kop12, Thm. 7.27, 7.29], as follows: 3.32/1.75 3.32/1.75 * 0 : 3.32/1.75 * 1 : 3.32/1.75 3.32/1.75 This graph has no strongly connected components. By [Kop12, Thm. 7.31], this implies finiteness of the dependency pair problem. 3.32/1.75 3.32/1.75 Thus, the original system is terminating if (P_1, R_0, static, formative) is finite. 3.32/1.75 3.32/1.75 We consider the dependency pair problem (P_1, R_0, static, formative). 3.32/1.75 3.32/1.75 We apply the subterm criterion with the following projection function: 3.32/1.75 3.32/1.75 nu(map#) = 2 3.32/1.75 3.32/1.75 Thus, we can orient the dependency pairs as follows: 3.32/1.75 3.32/1.75 nu(map#(F, cons(X, Y))) = cons(X, Y) |> Y = nu(map#(F, Y)) 3.32/1.75 3.32/1.75 By [Kop12, Thm. 7.35] and [Kop13, Thm. 5], we may replace a dependency pair problem (P_1, R_0, static, f) by ({}, R_0, static, f). By the empty set processor [Kop12, Thm. 7.15] this problem may be immediately removed. 3.32/1.75 3.32/1.75 As all dependency pair problems were succesfully simplified with sound (and complete) processors until nothing remained, we conclude termination. 3.32/1.75 3.32/1.75 3.32/1.75 +++ Citations +++ 3.32/1.75 3.32/1.75 [Kop12] C. Kop. Higher Order Termination. PhD Thesis, 2012. 3.32/1.75 [Kop13] C. Kop. Static Dependency Pairs with Accessibility. Unpublished manuscript, http://cl-informatik.uibk.ac.at/users/kop/static.pdf, 2013. 3.32/1.75 [KusIsoSakBla09] K. Kusakari, Y. Isogai, M. Sakai, and F. Blanqui. Static Dependency Pair Method Based On Strong Computability for Higher-Order Rewrite Systems. In volume 92(10) of IEICE Transactions on Information and Systems. 2007--2015, 2009. 3.32/1.75 EOF