/export/starexec/sandbox2/solver/bin/starexec_run_FirstOrder /export/starexec/sandbox2/benchmark/theBenchmark.xml /export/starexec/sandbox2/output/output_files -------------------------------------------------------------------------------- YES We consider the system theBenchmark. We are asked to determine termination of the following first-order TRS. 0 : [] --> o U11 : [o * o] --> o a!6220!6220U11 : [o * o] --> o a!6220!6220and : [o * o] --> o a!6220!6220isNat : [o] --> o a!6220!6220isNatIList : [o] --> o a!6220!6220isNatList : [o] --> o a!6220!6220length : [o] --> o a!6220!6220zeros : [] --> o and : [o * o] --> o cons : [o * o] --> o isNat : [o] --> o isNatIList : [o] --> o isNatList : [o] --> o length : [o] --> o mark : [o] --> o nil : [] --> o s : [o] --> o tt : [] --> o zeros : [] --> o a!6220!6220zeros => cons(0, zeros) a!6220!6220U11(tt, X) => s(a!6220!6220length(mark(X))) a!6220!6220and(tt, X) => mark(X) a!6220!6220isNat(0) => tt a!6220!6220isNat(length(X)) => a!6220!6220isNatList(X) a!6220!6220isNat(s(X)) => a!6220!6220isNat(X) a!6220!6220isNatIList(X) => a!6220!6220isNatList(X) a!6220!6220isNatIList(zeros) => tt a!6220!6220isNatIList(cons(X, Y)) => a!6220!6220and(a!6220!6220isNat(X), isNatIList(Y)) a!6220!6220isNatList(nil) => tt a!6220!6220isNatList(cons(X, Y)) => a!6220!6220and(a!6220!6220isNat(X), isNatList(Y)) a!6220!6220length(nil) => 0 a!6220!6220length(cons(X, Y)) => a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(Y), isNat(X)), Y) mark(zeros) => a!6220!6220zeros mark(U11(X, Y)) => a!6220!6220U11(mark(X), Y) mark(length(X)) => a!6220!6220length(mark(X)) mark(and(X, Y)) => a!6220!6220and(mark(X), Y) mark(isNat(X)) => a!6220!6220isNat(X) mark(isNatList(X)) => a!6220!6220isNatList(X) mark(isNatIList(X)) => a!6220!6220isNatIList(X) mark(cons(X, Y)) => cons(mark(X), Y) mark(0) => 0 mark(tt) => tt mark(s(X)) => s(mark(X)) mark(nil) => nil a!6220!6220zeros => zeros a!6220!6220U11(X, Y) => U11(X, Y) a!6220!6220length(X) => length(X) a!6220!6220and(X, Y) => and(X, Y) a!6220!6220isNat(X) => isNat(X) a!6220!6220isNatList(X) => isNatList(X) a!6220!6220isNatIList(X) => isNatIList(X) We use rule removal, following [Kop12, Theorem 2.23]. This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): a!6220!6220zeros >? cons(0, zeros) a!6220!6220U11(tt, X) >? s(a!6220!6220length(mark(X))) a!6220!6220and(tt, X) >? mark(X) a!6220!6220isNat(0) >? tt a!6220!6220isNat(length(X)) >? a!6220!6220isNatList(X) a!6220!6220isNat(s(X)) >? a!6220!6220isNat(X) a!6220!6220isNatIList(X) >? a!6220!6220isNatList(X) a!6220!6220isNatIList(zeros) >? tt a!6220!6220isNatIList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatIList(Y)) a!6220!6220isNatList(nil) >? tt a!6220!6220isNatList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatList(Y)) a!6220!6220length(nil) >? 0 a!6220!6220length(cons(X, Y)) >? a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(Y), isNat(X)), Y) mark(zeros) >? a!6220!6220zeros mark(U11(X, Y)) >? a!6220!6220U11(mark(X), Y) mark(length(X)) >? a!6220!6220length(mark(X)) mark(and(X, Y)) >? a!6220!6220and(mark(X), Y) mark(isNat(X)) >? a!6220!6220isNat(X) mark(isNatList(X)) >? a!6220!6220isNatList(X) mark(isNatIList(X)) >? a!6220!6220isNatIList(X) mark(cons(X, Y)) >? cons(mark(X), Y) mark(0) >? 0 mark(tt) >? tt mark(s(X)) >? s(mark(X)) mark(nil) >? nil a!6220!6220zeros >? zeros a!6220!6220U11(X, Y) >? U11(X, Y) a!6220!6220length(X) >? length(X) a!6220!6220and(X, Y) >? and(X, Y) a!6220!6220isNat(X) >? isNat(X) a!6220!6220isNatList(X) >? isNatList(X) a!6220!6220isNatIList(X) >? isNatIList(X) We orient these requirements with a polynomial interpretation in the natural numbers. The following interpretation satisfies the requirements: 0 = 0 U11 = \y0y1.y0 + 2y1 a!6220!6220U11 = \y0y1.y0 + 2y1 a!6220!6220and = \y0y1.y0 + 2y1 a!6220!6220isNat = \y0.y0 a!6220!6220isNatIList = \y0.y0 a!6220!6220isNatList = \y0.y0 a!6220!6220length = \y0.y0 a!6220!6220zeros = 0 and = \y0y1.y0 + 2y1 cons = \y0y1.2y0 + 3y1 isNat = \y0.y0 isNatIList = \y0.y0 isNatList = \y0.y0 length = \y0.y0 mark = \y0.y0 nil = 1 s = \y0.2y0 tt = 0 zeros = 0 Using this interpretation, the requirements translate to: [[a!6220!6220zeros]] = 0 >= 0 = [[cons(0, zeros)]] [[a!6220!6220U11(tt, _x0)]] = 2x0 >= 2x0 = [[s(a!6220!6220length(mark(_x0)))]] [[a!6220!6220and(tt, _x0)]] = 2x0 >= x0 = [[mark(_x0)]] [[a!6220!6220isNat(0)]] = 0 >= 0 = [[tt]] [[a!6220!6220isNat(length(_x0))]] = x0 >= x0 = [[a!6220!6220isNatList(_x0)]] [[a!6220!6220isNat(s(_x0))]] = 2x0 >= x0 = [[a!6220!6220isNat(_x0)]] [[a!6220!6220isNatIList(_x0)]] = x0 >= x0 = [[a!6220!6220isNatList(_x0)]] [[a!6220!6220isNatIList(zeros)]] = 0 >= 0 = [[tt]] [[a!6220!6220isNatIList(cons(_x0, _x1))]] = 2x0 + 3x1 >= x0 + 2x1 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatIList(_x1))]] [[a!6220!6220isNatList(nil)]] = 1 > 0 = [[tt]] [[a!6220!6220isNatList(cons(_x0, _x1))]] = 2x0 + 3x1 >= x0 + 2x1 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatList(_x1))]] [[a!6220!6220length(nil)]] = 1 > 0 = [[0]] [[a!6220!6220length(cons(_x0, _x1))]] = 2x0 + 3x1 >= 2x0 + 3x1 = [[a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(_x1), isNat(_x0)), _x1)]] [[mark(zeros)]] = 0 >= 0 = [[a!6220!6220zeros]] [[mark(U11(_x0, _x1))]] = x0 + 2x1 >= x0 + 2x1 = [[a!6220!6220U11(mark(_x0), _x1)]] [[mark(length(_x0))]] = x0 >= x0 = [[a!6220!6220length(mark(_x0))]] [[mark(and(_x0, _x1))]] = x0 + 2x1 >= x0 + 2x1 = [[a!6220!6220and(mark(_x0), _x1)]] [[mark(isNat(_x0))]] = x0 >= x0 = [[a!6220!6220isNat(_x0)]] [[mark(isNatList(_x0))]] = x0 >= x0 = [[a!6220!6220isNatList(_x0)]] [[mark(isNatIList(_x0))]] = x0 >= x0 = [[a!6220!6220isNatIList(_x0)]] [[mark(cons(_x0, _x1))]] = 2x0 + 3x1 >= 2x0 + 3x1 = [[cons(mark(_x0), _x1)]] [[mark(0)]] = 0 >= 0 = [[0]] [[mark(tt)]] = 0 >= 0 = [[tt]] [[mark(s(_x0))]] = 2x0 >= 2x0 = [[s(mark(_x0))]] [[mark(nil)]] = 1 >= 1 = [[nil]] [[a!6220!6220zeros]] = 0 >= 0 = [[zeros]] [[a!6220!6220U11(_x0, _x1)]] = x0 + 2x1 >= x0 + 2x1 = [[U11(_x0, _x1)]] [[a!6220!6220length(_x0)]] = x0 >= x0 = [[length(_x0)]] [[a!6220!6220and(_x0, _x1)]] = x0 + 2x1 >= x0 + 2x1 = [[and(_x0, _x1)]] [[a!6220!6220isNat(_x0)]] = x0 >= x0 = [[isNat(_x0)]] [[a!6220!6220isNatList(_x0)]] = x0 >= x0 = [[isNatList(_x0)]] [[a!6220!6220isNatIList(_x0)]] = x0 >= x0 = [[isNatIList(_x0)]] We can thus remove the following rules: a!6220!6220isNatList(nil) => tt a!6220!6220length(nil) => 0 We use rule removal, following [Kop12, Theorem 2.23]. This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): a!6220!6220zeros >? cons(0, zeros) a!6220!6220U11(tt, X) >? s(a!6220!6220length(mark(X))) a!6220!6220and(tt, X) >? mark(X) a!6220!6220isNat(0) >? tt a!6220!6220isNat(length(X)) >? a!6220!6220isNatList(X) a!6220!6220isNat(s(X)) >? a!6220!6220isNat(X) a!6220!6220isNatIList(X) >? a!6220!6220isNatList(X) a!6220!6220isNatIList(zeros) >? tt a!6220!6220isNatIList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatIList(Y)) a!6220!6220isNatList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatList(Y)) a!6220!6220length(cons(X, Y)) >? a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(Y), isNat(X)), Y) mark(zeros) >? a!6220!6220zeros mark(U11(X, Y)) >? a!6220!6220U11(mark(X), Y) mark(length(X)) >? a!6220!6220length(mark(X)) mark(and(X, Y)) >? a!6220!6220and(mark(X), Y) mark(isNat(X)) >? a!6220!6220isNat(X) mark(isNatList(X)) >? a!6220!6220isNatList(X) mark(isNatIList(X)) >? a!6220!6220isNatIList(X) mark(cons(X, Y)) >? cons(mark(X), Y) mark(0) >? 0 mark(tt) >? tt mark(s(X)) >? s(mark(X)) mark(nil) >? nil a!6220!6220zeros >? zeros a!6220!6220U11(X, Y) >? U11(X, Y) a!6220!6220length(X) >? length(X) a!6220!6220and(X, Y) >? and(X, Y) a!6220!6220isNat(X) >? isNat(X) a!6220!6220isNatList(X) >? isNatList(X) a!6220!6220isNatIList(X) >? isNatIList(X) We orient these requirements with a polynomial interpretation in the natural numbers. The following interpretation satisfies the requirements: 0 = 0 U11 = \y0y1.y0 + 2y1 a!6220!6220U11 = \y0y1.y0 + 2y1 a!6220!6220and = \y0y1.y1 + 2y0 a!6220!6220isNat = \y0.y0 a!6220!6220isNatIList = \y0.2 + 2y0 a!6220!6220isNatList = \y0.y0 a!6220!6220length = \y0.2y0 a!6220!6220zeros = 0 and = \y0y1.y1 + 2y0 cons = \y0y1.2y0 + 2y1 isNat = \y0.y0 isNatIList = \y0.2 + 2y0 isNatList = \y0.y0 length = \y0.2y0 mark = \y0.y0 nil = 0 s = \y0.y0 tt = 0 zeros = 0 Using this interpretation, the requirements translate to: [[a!6220!6220zeros]] = 0 >= 0 = [[cons(0, zeros)]] [[a!6220!6220U11(tt, _x0)]] = 2x0 >= 2x0 = [[s(a!6220!6220length(mark(_x0)))]] [[a!6220!6220and(tt, _x0)]] = x0 >= x0 = [[mark(_x0)]] [[a!6220!6220isNat(0)]] = 0 >= 0 = [[tt]] [[a!6220!6220isNat(length(_x0))]] = 2x0 >= x0 = [[a!6220!6220isNatList(_x0)]] [[a!6220!6220isNat(s(_x0))]] = x0 >= x0 = [[a!6220!6220isNat(_x0)]] [[a!6220!6220isNatIList(_x0)]] = 2 + 2x0 > x0 = [[a!6220!6220isNatList(_x0)]] [[a!6220!6220isNatIList(zeros)]] = 2 > 0 = [[tt]] [[a!6220!6220isNatIList(cons(_x0, _x1))]] = 2 + 4x0 + 4x1 >= 2 + 2x0 + 2x1 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatIList(_x1))]] [[a!6220!6220isNatList(cons(_x0, _x1))]] = 2x0 + 2x1 >= x1 + 2x0 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatList(_x1))]] [[a!6220!6220length(cons(_x0, _x1))]] = 4x0 + 4x1 >= x0 + 4x1 = [[a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(_x1), isNat(_x0)), _x1)]] [[mark(zeros)]] = 0 >= 0 = [[a!6220!6220zeros]] [[mark(U11(_x0, _x1))]] = x0 + 2x1 >= x0 + 2x1 = [[a!6220!6220U11(mark(_x0), _x1)]] [[mark(length(_x0))]] = 2x0 >= 2x0 = [[a!6220!6220length(mark(_x0))]] [[mark(and(_x0, _x1))]] = x1 + 2x0 >= x1 + 2x0 = [[a!6220!6220and(mark(_x0), _x1)]] [[mark(isNat(_x0))]] = x0 >= x0 = [[a!6220!6220isNat(_x0)]] [[mark(isNatList(_x0))]] = x0 >= x0 = [[a!6220!6220isNatList(_x0)]] [[mark(isNatIList(_x0))]] = 2 + 2x0 >= 2 + 2x0 = [[a!6220!6220isNatIList(_x0)]] [[mark(cons(_x0, _x1))]] = 2x0 + 2x1 >= 2x0 + 2x1 = [[cons(mark(_x0), _x1)]] [[mark(0)]] = 0 >= 0 = [[0]] [[mark(tt)]] = 0 >= 0 = [[tt]] [[mark(s(_x0))]] = x0 >= x0 = [[s(mark(_x0))]] [[mark(nil)]] = 0 >= 0 = [[nil]] [[a!6220!6220zeros]] = 0 >= 0 = [[zeros]] [[a!6220!6220U11(_x0, _x1)]] = x0 + 2x1 >= x0 + 2x1 = [[U11(_x0, _x1)]] [[a!6220!6220length(_x0)]] = 2x0 >= 2x0 = [[length(_x0)]] [[a!6220!6220and(_x0, _x1)]] = x1 + 2x0 >= x1 + 2x0 = [[and(_x0, _x1)]] [[a!6220!6220isNat(_x0)]] = x0 >= x0 = [[isNat(_x0)]] [[a!6220!6220isNatList(_x0)]] = x0 >= x0 = [[isNatList(_x0)]] [[a!6220!6220isNatIList(_x0)]] = 2 + 2x0 >= 2 + 2x0 = [[isNatIList(_x0)]] We can thus remove the following rules: a!6220!6220isNatIList(X) => a!6220!6220isNatList(X) a!6220!6220isNatIList(zeros) => tt We use rule removal, following [Kop12, Theorem 2.23]. This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): a!6220!6220zeros >? cons(0, zeros) a!6220!6220U11(tt, X) >? s(a!6220!6220length(mark(X))) a!6220!6220and(tt, X) >? mark(X) a!6220!6220isNat(0) >? tt a!6220!6220isNat(length(X)) >? a!6220!6220isNatList(X) a!6220!6220isNat(s(X)) >? a!6220!6220isNat(X) a!6220!6220isNatIList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatIList(Y)) a!6220!6220isNatList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatList(Y)) a!6220!6220length(cons(X, Y)) >? a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(Y), isNat(X)), Y) mark(zeros) >? a!6220!6220zeros mark(U11(X, Y)) >? a!6220!6220U11(mark(X), Y) mark(length(X)) >? a!6220!6220length(mark(X)) mark(and(X, Y)) >? a!6220!6220and(mark(X), Y) mark(isNat(X)) >? a!6220!6220isNat(X) mark(isNatList(X)) >? a!6220!6220isNatList(X) mark(isNatIList(X)) >? a!6220!6220isNatIList(X) mark(cons(X, Y)) >? cons(mark(X), Y) mark(0) >? 0 mark(tt) >? tt mark(s(X)) >? s(mark(X)) mark(nil) >? nil a!6220!6220zeros >? zeros a!6220!6220U11(X, Y) >? U11(X, Y) a!6220!6220length(X) >? length(X) a!6220!6220and(X, Y) >? and(X, Y) a!6220!6220isNat(X) >? isNat(X) a!6220!6220isNatList(X) >? isNatList(X) a!6220!6220isNatIList(X) >? isNatIList(X) We orient these requirements with a polynomial interpretation in the natural numbers. The following interpretation satisfies the requirements: 0 = 0 U11 = \y0y1.y0 + 2y1 a!6220!6220U11 = \y0y1.y0 + 2y1 a!6220!6220and = \y0y1.y0 + 2y1 a!6220!6220isNat = \y0.2y0 a!6220!6220isNatIList = \y0.2y0 a!6220!6220isNatList = \y0.y0 a!6220!6220length = \y0.y0 a!6220!6220zeros = 0 and = \y0y1.y0 + 2y1 cons = \y0y1.2y0 + 3y1 isNat = \y0.y0 isNatIList = \y0.y0 isNatList = \y0.y0 length = \y0.y0 mark = \y0.2y0 nil = 3 s = \y0.y0 tt = 0 zeros = 0 Using this interpretation, the requirements translate to: [[a!6220!6220zeros]] = 0 >= 0 = [[cons(0, zeros)]] [[a!6220!6220U11(tt, _x0)]] = 2x0 >= 2x0 = [[s(a!6220!6220length(mark(_x0)))]] [[a!6220!6220and(tt, _x0)]] = 2x0 >= 2x0 = [[mark(_x0)]] [[a!6220!6220isNat(0)]] = 0 >= 0 = [[tt]] [[a!6220!6220isNat(length(_x0))]] = 2x0 >= x0 = [[a!6220!6220isNatList(_x0)]] [[a!6220!6220isNat(s(_x0))]] = 2x0 >= 2x0 = [[a!6220!6220isNat(_x0)]] [[a!6220!6220isNatIList(cons(_x0, _x1))]] = 4x0 + 6x1 >= 2x0 + 2x1 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatIList(_x1))]] [[a!6220!6220isNatList(cons(_x0, _x1))]] = 2x0 + 3x1 >= 2x0 + 2x1 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatList(_x1))]] [[a!6220!6220length(cons(_x0, _x1))]] = 2x0 + 3x1 >= 2x0 + 3x1 = [[a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(_x1), isNat(_x0)), _x1)]] [[mark(zeros)]] = 0 >= 0 = [[a!6220!6220zeros]] [[mark(U11(_x0, _x1))]] = 2x0 + 4x1 >= 2x0 + 2x1 = [[a!6220!6220U11(mark(_x0), _x1)]] [[mark(length(_x0))]] = 2x0 >= 2x0 = [[a!6220!6220length(mark(_x0))]] [[mark(and(_x0, _x1))]] = 2x0 + 4x1 >= 2x0 + 2x1 = [[a!6220!6220and(mark(_x0), _x1)]] [[mark(isNat(_x0))]] = 2x0 >= 2x0 = [[a!6220!6220isNat(_x0)]] [[mark(isNatList(_x0))]] = 2x0 >= x0 = [[a!6220!6220isNatList(_x0)]] [[mark(isNatIList(_x0))]] = 2x0 >= 2x0 = [[a!6220!6220isNatIList(_x0)]] [[mark(cons(_x0, _x1))]] = 4x0 + 6x1 >= 3x1 + 4x0 = [[cons(mark(_x0), _x1)]] [[mark(0)]] = 0 >= 0 = [[0]] [[mark(tt)]] = 0 >= 0 = [[tt]] [[mark(s(_x0))]] = 2x0 >= 2x0 = [[s(mark(_x0))]] [[mark(nil)]] = 6 > 3 = [[nil]] [[a!6220!6220zeros]] = 0 >= 0 = [[zeros]] [[a!6220!6220U11(_x0, _x1)]] = x0 + 2x1 >= x0 + 2x1 = [[U11(_x0, _x1)]] [[a!6220!6220length(_x0)]] = x0 >= x0 = [[length(_x0)]] [[a!6220!6220and(_x0, _x1)]] = x0 + 2x1 >= x0 + 2x1 = [[and(_x0, _x1)]] [[a!6220!6220isNat(_x0)]] = 2x0 >= x0 = [[isNat(_x0)]] [[a!6220!6220isNatList(_x0)]] = x0 >= x0 = [[isNatList(_x0)]] [[a!6220!6220isNatIList(_x0)]] = 2x0 >= x0 = [[isNatIList(_x0)]] We can thus remove the following rules: mark(nil) => nil We use rule removal, following [Kop12, Theorem 2.23]. This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): a!6220!6220zeros >? cons(0, zeros) a!6220!6220U11(tt, X) >? s(a!6220!6220length(mark(X))) a!6220!6220and(tt, X) >? mark(X) a!6220!6220isNat(0) >? tt a!6220!6220isNat(length(X)) >? a!6220!6220isNatList(X) a!6220!6220isNat(s(X)) >? a!6220!6220isNat(X) a!6220!6220isNatIList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatIList(Y)) a!6220!6220isNatList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatList(Y)) a!6220!6220length(cons(X, Y)) >? a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(Y), isNat(X)), Y) mark(zeros) >? a!6220!6220zeros mark(U11(X, Y)) >? a!6220!6220U11(mark(X), Y) mark(length(X)) >? a!6220!6220length(mark(X)) mark(and(X, Y)) >? a!6220!6220and(mark(X), Y) mark(isNat(X)) >? a!6220!6220isNat(X) mark(isNatList(X)) >? a!6220!6220isNatList(X) mark(isNatIList(X)) >? a!6220!6220isNatIList(X) mark(cons(X, Y)) >? cons(mark(X), Y) mark(0) >? 0 mark(tt) >? tt mark(s(X)) >? s(mark(X)) a!6220!6220zeros >? zeros a!6220!6220U11(X, Y) >? U11(X, Y) a!6220!6220length(X) >? length(X) a!6220!6220and(X, Y) >? and(X, Y) a!6220!6220isNat(X) >? isNat(X) a!6220!6220isNatList(X) >? isNatList(X) a!6220!6220isNatIList(X) >? isNatIList(X) We orient these requirements with a polynomial interpretation in the natural numbers. The following interpretation satisfies the requirements: 0 = 0 U11 = \y0y1.1 + y1 + 2y0 a!6220!6220U11 = \y0y1.1 + y1 + 2y0 a!6220!6220and = \y0y1.y0 + y1 a!6220!6220isNat = \y0.y0 a!6220!6220isNatIList = \y0.2y0 a!6220!6220isNatList = \y0.y0 a!6220!6220length = \y0.1 + y0 a!6220!6220zeros = 0 and = \y0y1.y0 + y1 cons = \y0y1.2y0 + 3y1 isNat = \y0.y0 isNatIList = \y0.2y0 isNatList = \y0.y0 length = \y0.1 + y0 mark = \y0.y0 s = \y0.y0 tt = 0 zeros = 0 Using this interpretation, the requirements translate to: [[a!6220!6220zeros]] = 0 >= 0 = [[cons(0, zeros)]] [[a!6220!6220U11(tt, _x0)]] = 1 + x0 >= 1 + x0 = [[s(a!6220!6220length(mark(_x0)))]] [[a!6220!6220and(tt, _x0)]] = x0 >= x0 = [[mark(_x0)]] [[a!6220!6220isNat(0)]] = 0 >= 0 = [[tt]] [[a!6220!6220isNat(length(_x0))]] = 1 + x0 > x0 = [[a!6220!6220isNatList(_x0)]] [[a!6220!6220isNat(s(_x0))]] = x0 >= x0 = [[a!6220!6220isNat(_x0)]] [[a!6220!6220isNatIList(cons(_x0, _x1))]] = 4x0 + 6x1 >= x0 + 2x1 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatIList(_x1))]] [[a!6220!6220isNatList(cons(_x0, _x1))]] = 2x0 + 3x1 >= x0 + x1 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatList(_x1))]] [[a!6220!6220length(cons(_x0, _x1))]] = 1 + 2x0 + 3x1 >= 1 + 2x0 + 3x1 = [[a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(_x1), isNat(_x0)), _x1)]] [[mark(zeros)]] = 0 >= 0 = [[a!6220!6220zeros]] [[mark(U11(_x0, _x1))]] = 1 + x1 + 2x0 >= 1 + x1 + 2x0 = [[a!6220!6220U11(mark(_x0), _x1)]] [[mark(length(_x0))]] = 1 + x0 >= 1 + x0 = [[a!6220!6220length(mark(_x0))]] [[mark(and(_x0, _x1))]] = x0 + x1 >= x0 + x1 = [[a!6220!6220and(mark(_x0), _x1)]] [[mark(isNat(_x0))]] = x0 >= x0 = [[a!6220!6220isNat(_x0)]] [[mark(isNatList(_x0))]] = x0 >= x0 = [[a!6220!6220isNatList(_x0)]] [[mark(isNatIList(_x0))]] = 2x0 >= 2x0 = [[a!6220!6220isNatIList(_x0)]] [[mark(cons(_x0, _x1))]] = 2x0 + 3x1 >= 2x0 + 3x1 = [[cons(mark(_x0), _x1)]] [[mark(0)]] = 0 >= 0 = [[0]] [[mark(tt)]] = 0 >= 0 = [[tt]] [[mark(s(_x0))]] = x0 >= x0 = [[s(mark(_x0))]] [[a!6220!6220zeros]] = 0 >= 0 = [[zeros]] [[a!6220!6220U11(_x0, _x1)]] = 1 + x1 + 2x0 >= 1 + x1 + 2x0 = [[U11(_x0, _x1)]] [[a!6220!6220length(_x0)]] = 1 + x0 >= 1 + x0 = [[length(_x0)]] [[a!6220!6220and(_x0, _x1)]] = x0 + x1 >= x0 + x1 = [[and(_x0, _x1)]] [[a!6220!6220isNat(_x0)]] = x0 >= x0 = [[isNat(_x0)]] [[a!6220!6220isNatList(_x0)]] = x0 >= x0 = [[isNatList(_x0)]] [[a!6220!6220isNatIList(_x0)]] = 2x0 >= 2x0 = [[isNatIList(_x0)]] We can thus remove the following rules: a!6220!6220isNat(length(X)) => a!6220!6220isNatList(X) We use rule removal, following [Kop12, Theorem 2.23]. This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): a!6220!6220zeros >? cons(0, zeros) a!6220!6220U11(tt, X) >? s(a!6220!6220length(mark(X))) a!6220!6220and(tt, X) >? mark(X) a!6220!6220isNat(0) >? tt a!6220!6220isNat(s(X)) >? a!6220!6220isNat(X) a!6220!6220isNatIList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatIList(Y)) a!6220!6220isNatList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatList(Y)) a!6220!6220length(cons(X, Y)) >? a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(Y), isNat(X)), Y) mark(zeros) >? a!6220!6220zeros mark(U11(X, Y)) >? a!6220!6220U11(mark(X), Y) mark(length(X)) >? a!6220!6220length(mark(X)) mark(and(X, Y)) >? a!6220!6220and(mark(X), Y) mark(isNat(X)) >? a!6220!6220isNat(X) mark(isNatList(X)) >? a!6220!6220isNatList(X) mark(isNatIList(X)) >? a!6220!6220isNatIList(X) mark(cons(X, Y)) >? cons(mark(X), Y) mark(0) >? 0 mark(tt) >? tt mark(s(X)) >? s(mark(X)) a!6220!6220zeros >? zeros a!6220!6220U11(X, Y) >? U11(X, Y) a!6220!6220length(X) >? length(X) a!6220!6220and(X, Y) >? and(X, Y) a!6220!6220isNat(X) >? isNat(X) a!6220!6220isNatList(X) >? isNatList(X) a!6220!6220isNatIList(X) >? isNatIList(X) We orient these requirements with a polynomial interpretation in the natural numbers. The following interpretation satisfies the requirements: 0 = 0 U11 = \y0y1.1 + y0 + y1 a!6220!6220U11 = \y0y1.1 + y0 + 2y1 a!6220!6220and = \y0y1.y0 + 2y1 a!6220!6220isNat = \y0.y0 a!6220!6220isNatIList = \y0.3y0 a!6220!6220isNatList = \y0.y0 a!6220!6220length = \y0.1 + y0 a!6220!6220zeros = 0 and = \y0y1.y0 + y1 cons = \y0y1.2y0 + 3y1 isNat = \y0.y0 isNatIList = \y0.2y0 isNatList = \y0.y0 length = \y0.1 + y0 mark = \y0.2y0 s = \y0.y0 tt = 0 zeros = 0 Using this interpretation, the requirements translate to: [[a!6220!6220zeros]] = 0 >= 0 = [[cons(0, zeros)]] [[a!6220!6220U11(tt, _x0)]] = 1 + 2x0 >= 1 + 2x0 = [[s(a!6220!6220length(mark(_x0)))]] [[a!6220!6220and(tt, _x0)]] = 2x0 >= 2x0 = [[mark(_x0)]] [[a!6220!6220isNat(0)]] = 0 >= 0 = [[tt]] [[a!6220!6220isNat(s(_x0))]] = x0 >= x0 = [[a!6220!6220isNat(_x0)]] [[a!6220!6220isNatIList(cons(_x0, _x1))]] = 6x0 + 9x1 >= x0 + 4x1 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatIList(_x1))]] [[a!6220!6220isNatList(cons(_x0, _x1))]] = 2x0 + 3x1 >= x0 + 2x1 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatList(_x1))]] [[a!6220!6220length(cons(_x0, _x1))]] = 1 + 2x0 + 3x1 >= 1 + 2x0 + 3x1 = [[a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(_x1), isNat(_x0)), _x1)]] [[mark(zeros)]] = 0 >= 0 = [[a!6220!6220zeros]] [[mark(U11(_x0, _x1))]] = 2 + 2x0 + 2x1 > 1 + 2x0 + 2x1 = [[a!6220!6220U11(mark(_x0), _x1)]] [[mark(length(_x0))]] = 2 + 2x0 > 1 + 2x0 = [[a!6220!6220length(mark(_x0))]] [[mark(and(_x0, _x1))]] = 2x0 + 2x1 >= 2x0 + 2x1 = [[a!6220!6220and(mark(_x0), _x1)]] [[mark(isNat(_x0))]] = 2x0 >= x0 = [[a!6220!6220isNat(_x0)]] [[mark(isNatList(_x0))]] = 2x0 >= x0 = [[a!6220!6220isNatList(_x0)]] [[mark(isNatIList(_x0))]] = 4x0 >= 3x0 = [[a!6220!6220isNatIList(_x0)]] [[mark(cons(_x0, _x1))]] = 4x0 + 6x1 >= 3x1 + 4x0 = [[cons(mark(_x0), _x1)]] [[mark(0)]] = 0 >= 0 = [[0]] [[mark(tt)]] = 0 >= 0 = [[tt]] [[mark(s(_x0))]] = 2x0 >= 2x0 = [[s(mark(_x0))]] [[a!6220!6220zeros]] = 0 >= 0 = [[zeros]] [[a!6220!6220U11(_x0, _x1)]] = 1 + x0 + 2x1 >= 1 + x0 + x1 = [[U11(_x0, _x1)]] [[a!6220!6220length(_x0)]] = 1 + x0 >= 1 + x0 = [[length(_x0)]] [[a!6220!6220and(_x0, _x1)]] = x0 + 2x1 >= x0 + x1 = [[and(_x0, _x1)]] [[a!6220!6220isNat(_x0)]] = x0 >= x0 = [[isNat(_x0)]] [[a!6220!6220isNatList(_x0)]] = x0 >= x0 = [[isNatList(_x0)]] [[a!6220!6220isNatIList(_x0)]] = 3x0 >= 2x0 = [[isNatIList(_x0)]] We can thus remove the following rules: mark(U11(X, Y)) => a!6220!6220U11(mark(X), Y) mark(length(X)) => a!6220!6220length(mark(X)) We use rule removal, following [Kop12, Theorem 2.23]. This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): a!6220!6220zeros >? cons(0, zeros) a!6220!6220U11(tt, X) >? s(a!6220!6220length(mark(X))) a!6220!6220and(tt, X) >? mark(X) a!6220!6220isNat(0) >? tt a!6220!6220isNat(s(X)) >? a!6220!6220isNat(X) a!6220!6220isNatIList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatIList(Y)) a!6220!6220isNatList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatList(Y)) a!6220!6220length(cons(X, Y)) >? a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(Y), isNat(X)), Y) mark(zeros) >? a!6220!6220zeros mark(and(X, Y)) >? a!6220!6220and(mark(X), Y) mark(isNat(X)) >? a!6220!6220isNat(X) mark(isNatList(X)) >? a!6220!6220isNatList(X) mark(isNatIList(X)) >? a!6220!6220isNatIList(X) mark(cons(X, Y)) >? cons(mark(X), Y) mark(0) >? 0 mark(tt) >? tt mark(s(X)) >? s(mark(X)) a!6220!6220zeros >? zeros a!6220!6220U11(X, Y) >? U11(X, Y) a!6220!6220length(X) >? length(X) a!6220!6220and(X, Y) >? and(X, Y) a!6220!6220isNat(X) >? isNat(X) a!6220!6220isNatList(X) >? isNatList(X) a!6220!6220isNatIList(X) >? isNatIList(X) We orient these requirements with a polynomial interpretation in the natural numbers. The following interpretation satisfies the requirements: 0 = 0 U11 = \y0y1.y0 + y1 a!6220!6220U11 = \y0y1.1 + y0 + 2y1 a!6220!6220and = \y0y1.y0 + 2y1 a!6220!6220isNat = \y0.2y0 a!6220!6220isNatIList = \y0.2y0 a!6220!6220isNatList = \y0.y0 a!6220!6220length = \y0.1 + y0 a!6220!6220zeros = 0 and = \y0y1.y0 + y1 cons = \y0y1.2y0 + 3y1 isNat = \y0.y0 isNatIList = \y0.2y0 isNatList = \y0.y0 length = \y0.y0 mark = \y0.2y0 s = \y0.y0 tt = 0 zeros = 0 Using this interpretation, the requirements translate to: [[a!6220!6220zeros]] = 0 >= 0 = [[cons(0, zeros)]] [[a!6220!6220U11(tt, _x0)]] = 1 + 2x0 >= 1 + 2x0 = [[s(a!6220!6220length(mark(_x0)))]] [[a!6220!6220and(tt, _x0)]] = 2x0 >= 2x0 = [[mark(_x0)]] [[a!6220!6220isNat(0)]] = 0 >= 0 = [[tt]] [[a!6220!6220isNat(s(_x0))]] = 2x0 >= 2x0 = [[a!6220!6220isNat(_x0)]] [[a!6220!6220isNatIList(cons(_x0, _x1))]] = 4x0 + 6x1 >= 2x0 + 4x1 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatIList(_x1))]] [[a!6220!6220isNatList(cons(_x0, _x1))]] = 2x0 + 3x1 >= 2x0 + 2x1 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatList(_x1))]] [[a!6220!6220length(cons(_x0, _x1))]] = 1 + 2x0 + 3x1 >= 1 + 2x0 + 3x1 = [[a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(_x1), isNat(_x0)), _x1)]] [[mark(zeros)]] = 0 >= 0 = [[a!6220!6220zeros]] [[mark(and(_x0, _x1))]] = 2x0 + 2x1 >= 2x0 + 2x1 = [[a!6220!6220and(mark(_x0), _x1)]] [[mark(isNat(_x0))]] = 2x0 >= 2x0 = [[a!6220!6220isNat(_x0)]] [[mark(isNatList(_x0))]] = 2x0 >= x0 = [[a!6220!6220isNatList(_x0)]] [[mark(isNatIList(_x0))]] = 4x0 >= 2x0 = [[a!6220!6220isNatIList(_x0)]] [[mark(cons(_x0, _x1))]] = 4x0 + 6x1 >= 3x1 + 4x0 = [[cons(mark(_x0), _x1)]] [[mark(0)]] = 0 >= 0 = [[0]] [[mark(tt)]] = 0 >= 0 = [[tt]] [[mark(s(_x0))]] = 2x0 >= 2x0 = [[s(mark(_x0))]] [[a!6220!6220zeros]] = 0 >= 0 = [[zeros]] [[a!6220!6220U11(_x0, _x1)]] = 1 + x0 + 2x1 > x0 + x1 = [[U11(_x0, _x1)]] [[a!6220!6220length(_x0)]] = 1 + x0 > x0 = [[length(_x0)]] [[a!6220!6220and(_x0, _x1)]] = x0 + 2x1 >= x0 + x1 = [[and(_x0, _x1)]] [[a!6220!6220isNat(_x0)]] = 2x0 >= x0 = [[isNat(_x0)]] [[a!6220!6220isNatList(_x0)]] = x0 >= x0 = [[isNatList(_x0)]] [[a!6220!6220isNatIList(_x0)]] = 2x0 >= 2x0 = [[isNatIList(_x0)]] We can thus remove the following rules: a!6220!6220U11(X, Y) => U11(X, Y) a!6220!6220length(X) => length(X) We use rule removal, following [Kop12, Theorem 2.23]. This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): a!6220!6220zeros >? cons(0, zeros) a!6220!6220U11(tt, X) >? s(a!6220!6220length(mark(X))) a!6220!6220and(tt, X) >? mark(X) a!6220!6220isNat(0) >? tt a!6220!6220isNat(s(X)) >? a!6220!6220isNat(X) a!6220!6220isNatIList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatIList(Y)) a!6220!6220isNatList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatList(Y)) a!6220!6220length(cons(X, Y)) >? a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(Y), isNat(X)), Y) mark(zeros) >? a!6220!6220zeros mark(and(X, Y)) >? a!6220!6220and(mark(X), Y) mark(isNat(X)) >? a!6220!6220isNat(X) mark(isNatList(X)) >? a!6220!6220isNatList(X) mark(isNatIList(X)) >? a!6220!6220isNatIList(X) mark(cons(X, Y)) >? cons(mark(X), Y) mark(0) >? 0 mark(tt) >? tt mark(s(X)) >? s(mark(X)) a!6220!6220zeros >? zeros a!6220!6220and(X, Y) >? and(X, Y) a!6220!6220isNat(X) >? isNat(X) a!6220!6220isNatList(X) >? isNatList(X) a!6220!6220isNatIList(X) >? isNatIList(X) We orient these requirements with a polynomial interpretation in the natural numbers. The following interpretation satisfies the requirements: 0 = 0 a!6220!6220U11 = \y0y1.y0 + 2y1 a!6220!6220and = \y0y1.y0 + 2y1 a!6220!6220isNat = \y0.y0 a!6220!6220isNatIList = \y0.2 + y0 a!6220!6220isNatList = \y0.y0 a!6220!6220length = \y0.y0 a!6220!6220zeros = 0 and = \y0y1.y0 + 2y1 cons = \y0y1.2y0 + 3y1 isNat = \y0.y0 isNatIList = \y0.1 + y0 isNatList = \y0.y0 mark = \y0.2y0 s = \y0.y0 tt = 0 zeros = 0 Using this interpretation, the requirements translate to: [[a!6220!6220zeros]] = 0 >= 0 = [[cons(0, zeros)]] [[a!6220!6220U11(tt, _x0)]] = 2x0 >= 2x0 = [[s(a!6220!6220length(mark(_x0)))]] [[a!6220!6220and(tt, _x0)]] = 2x0 >= 2x0 = [[mark(_x0)]] [[a!6220!6220isNat(0)]] = 0 >= 0 = [[tt]] [[a!6220!6220isNat(s(_x0))]] = x0 >= x0 = [[a!6220!6220isNat(_x0)]] [[a!6220!6220isNatIList(cons(_x0, _x1))]] = 2 + 2x0 + 3x1 >= 2 + x0 + 2x1 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatIList(_x1))]] [[a!6220!6220isNatList(cons(_x0, _x1))]] = 2x0 + 3x1 >= x0 + 2x1 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatList(_x1))]] [[a!6220!6220length(cons(_x0, _x1))]] = 2x0 + 3x1 >= 2x0 + 3x1 = [[a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(_x1), isNat(_x0)), _x1)]] [[mark(zeros)]] = 0 >= 0 = [[a!6220!6220zeros]] [[mark(and(_x0, _x1))]] = 2x0 + 4x1 >= 2x0 + 2x1 = [[a!6220!6220and(mark(_x0), _x1)]] [[mark(isNat(_x0))]] = 2x0 >= x0 = [[a!6220!6220isNat(_x0)]] [[mark(isNatList(_x0))]] = 2x0 >= x0 = [[a!6220!6220isNatList(_x0)]] [[mark(isNatIList(_x0))]] = 2 + 2x0 >= 2 + x0 = [[a!6220!6220isNatIList(_x0)]] [[mark(cons(_x0, _x1))]] = 4x0 + 6x1 >= 3x1 + 4x0 = [[cons(mark(_x0), _x1)]] [[mark(0)]] = 0 >= 0 = [[0]] [[mark(tt)]] = 0 >= 0 = [[tt]] [[mark(s(_x0))]] = 2x0 >= 2x0 = [[s(mark(_x0))]] [[a!6220!6220zeros]] = 0 >= 0 = [[zeros]] [[a!6220!6220and(_x0, _x1)]] = x0 + 2x1 >= x0 + 2x1 = [[and(_x0, _x1)]] [[a!6220!6220isNat(_x0)]] = x0 >= x0 = [[isNat(_x0)]] [[a!6220!6220isNatList(_x0)]] = x0 >= x0 = [[isNatList(_x0)]] [[a!6220!6220isNatIList(_x0)]] = 2 + x0 > 1 + x0 = [[isNatIList(_x0)]] We can thus remove the following rules: a!6220!6220isNatIList(X) => isNatIList(X) We use rule removal, following [Kop12, Theorem 2.23]. This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): a!6220!6220zeros >? cons(0, zeros) a!6220!6220U11(tt, X) >? s(a!6220!6220length(mark(X))) a!6220!6220and(tt, X) >? mark(X) a!6220!6220isNat(0) >? tt a!6220!6220isNat(s(X)) >? a!6220!6220isNat(X) a!6220!6220isNatIList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatIList(Y)) a!6220!6220isNatList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatList(Y)) a!6220!6220length(cons(X, Y)) >? a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(Y), isNat(X)), Y) mark(zeros) >? a!6220!6220zeros mark(and(X, Y)) >? a!6220!6220and(mark(X), Y) mark(isNat(X)) >? a!6220!6220isNat(X) mark(isNatList(X)) >? a!6220!6220isNatList(X) mark(isNatIList(X)) >? a!6220!6220isNatIList(X) mark(cons(X, Y)) >? cons(mark(X), Y) mark(0) >? 0 mark(tt) >? tt mark(s(X)) >? s(mark(X)) a!6220!6220zeros >? zeros a!6220!6220and(X, Y) >? and(X, Y) a!6220!6220isNat(X) >? isNat(X) a!6220!6220isNatList(X) >? isNatList(X) We orient these requirements with a polynomial interpretation in the natural numbers. The following interpretation satisfies the requirements: 0 = 0 a!6220!6220U11 = \y0y1.2 + y0 + 2y1 a!6220!6220and = \y0y1.1 + y0 + 2y1 a!6220!6220isNat = \y0.1 + y0 a!6220!6220isNatIList = \y0.2y0 a!6220!6220isNatList = \y0.y0 a!6220!6220length = \y0.1 + y0 a!6220!6220zeros = 2 and = \y0y1.1 + y0 + y1 cons = \y0y1.2 + 2y0 + 3y1 isNat = \y0.y0 isNatIList = \y0.2y0 isNatList = \y0.y0 mark = \y0.2 + 2y0 s = \y0.y0 tt = 1 zeros = 0 Using this interpretation, the requirements translate to: [[a!6220!6220zeros]] = 2 >= 2 = [[cons(0, zeros)]] [[a!6220!6220U11(tt, _x0)]] = 3 + 2x0 >= 3 + 2x0 = [[s(a!6220!6220length(mark(_x0)))]] [[a!6220!6220and(tt, _x0)]] = 2 + 2x0 >= 2 + 2x0 = [[mark(_x0)]] [[a!6220!6220isNat(0)]] = 1 >= 1 = [[tt]] [[a!6220!6220isNat(s(_x0))]] = 1 + x0 >= 1 + x0 = [[a!6220!6220isNat(_x0)]] [[a!6220!6220isNatIList(cons(_x0, _x1))]] = 4 + 4x0 + 6x1 > 2 + x0 + 4x1 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatIList(_x1))]] [[a!6220!6220isNatList(cons(_x0, _x1))]] = 2 + 2x0 + 3x1 >= 2 + x0 + 2x1 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatList(_x1))]] [[a!6220!6220length(cons(_x0, _x1))]] = 3 + 2x0 + 3x1 >= 3 + 2x0 + 3x1 = [[a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(_x1), isNat(_x0)), _x1)]] [[mark(zeros)]] = 2 >= 2 = [[a!6220!6220zeros]] [[mark(and(_x0, _x1))]] = 4 + 2x0 + 2x1 > 3 + 2x0 + 2x1 = [[a!6220!6220and(mark(_x0), _x1)]] [[mark(isNat(_x0))]] = 2 + 2x0 > 1 + x0 = [[a!6220!6220isNat(_x0)]] [[mark(isNatList(_x0))]] = 2 + 2x0 > x0 = [[a!6220!6220isNatList(_x0)]] [[mark(isNatIList(_x0))]] = 2 + 4x0 > 2x0 = [[a!6220!6220isNatIList(_x0)]] [[mark(cons(_x0, _x1))]] = 6 + 4x0 + 6x1 >= 6 + 3x1 + 4x0 = [[cons(mark(_x0), _x1)]] [[mark(0)]] = 2 > 0 = [[0]] [[mark(tt)]] = 4 > 1 = [[tt]] [[mark(s(_x0))]] = 2 + 2x0 >= 2 + 2x0 = [[s(mark(_x0))]] [[a!6220!6220zeros]] = 2 > 0 = [[zeros]] [[a!6220!6220and(_x0, _x1)]] = 1 + x0 + 2x1 >= 1 + x0 + x1 = [[and(_x0, _x1)]] [[a!6220!6220isNat(_x0)]] = 1 + x0 > x0 = [[isNat(_x0)]] [[a!6220!6220isNatList(_x0)]] = x0 >= x0 = [[isNatList(_x0)]] We can thus remove the following rules: a!6220!6220isNatIList(cons(X, Y)) => a!6220!6220and(a!6220!6220isNat(X), isNatIList(Y)) mark(and(X, Y)) => a!6220!6220and(mark(X), Y) mark(isNat(X)) => a!6220!6220isNat(X) mark(isNatList(X)) => a!6220!6220isNatList(X) mark(isNatIList(X)) => a!6220!6220isNatIList(X) mark(0) => 0 mark(tt) => tt a!6220!6220zeros => zeros a!6220!6220isNat(X) => isNat(X) We use rule removal, following [Kop12, Theorem 2.23]. This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): a!6220!6220zeros >? cons(0, zeros) a!6220!6220U11(tt, X) >? s(a!6220!6220length(mark(X))) a!6220!6220and(tt, X) >? mark(X) a!6220!6220isNat(0) >? tt a!6220!6220isNat(s(X)) >? a!6220!6220isNat(X) a!6220!6220isNatList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatList(Y)) a!6220!6220length(cons(X, Y)) >? a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(Y), isNat(X)), Y) mark(zeros) >? a!6220!6220zeros mark(cons(X, Y)) >? cons(mark(X), Y) mark(s(X)) >? s(mark(X)) a!6220!6220and(X, Y) >? and(X, Y) a!6220!6220isNatList(X) >? isNatList(X) We orient these requirements with a polynomial interpretation in the natural numbers. The following interpretation satisfies the requirements: 0 = 0 a!6220!6220U11 = \y0y1.y0 + 2y1 a!6220!6220and = \y0y1.y0 + 2y1 a!6220!6220isNat = \y0.1 + 2y0 a!6220!6220isNatList = \y0.1 + y0 a!6220!6220length = \y0.1 + y0 a!6220!6220zeros = 0 and = \y0y1.y0 + y1 cons = \y0y1.2y0 + 3y1 isNat = \y0.y0 isNatList = \y0.y0 mark = \y0.2y0 s = \y0.y0 tt = 1 zeros = 0 Using this interpretation, the requirements translate to: [[a!6220!6220zeros]] = 0 >= 0 = [[cons(0, zeros)]] [[a!6220!6220U11(tt, _x0)]] = 1 + 2x0 >= 1 + 2x0 = [[s(a!6220!6220length(mark(_x0)))]] [[a!6220!6220and(tt, _x0)]] = 1 + 2x0 > 2x0 = [[mark(_x0)]] [[a!6220!6220isNat(0)]] = 1 >= 1 = [[tt]] [[a!6220!6220isNat(s(_x0))]] = 1 + 2x0 >= 1 + 2x0 = [[a!6220!6220isNat(_x0)]] [[a!6220!6220isNatList(cons(_x0, _x1))]] = 1 + 2x0 + 3x1 >= 1 + 2x0 + 2x1 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatList(_x1))]] [[a!6220!6220length(cons(_x0, _x1))]] = 1 + 2x0 + 3x1 >= 1 + 2x0 + 3x1 = [[a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(_x1), isNat(_x0)), _x1)]] [[mark(zeros)]] = 0 >= 0 = [[a!6220!6220zeros]] [[mark(cons(_x0, _x1))]] = 4x0 + 6x1 >= 3x1 + 4x0 = [[cons(mark(_x0), _x1)]] [[mark(s(_x0))]] = 2x0 >= 2x0 = [[s(mark(_x0))]] [[a!6220!6220and(_x0, _x1)]] = x0 + 2x1 >= x0 + x1 = [[and(_x0, _x1)]] [[a!6220!6220isNatList(_x0)]] = 1 + x0 > x0 = [[isNatList(_x0)]] We can thus remove the following rules: a!6220!6220and(tt, X) => mark(X) a!6220!6220isNatList(X) => isNatList(X) We use rule removal, following [Kop12, Theorem 2.23]. This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): a!6220!6220zeros >? cons(0, zeros) a!6220!6220U11(tt, X) >? s(a!6220!6220length(mark(X))) a!6220!6220isNat(0) >? tt a!6220!6220isNat(s(X)) >? a!6220!6220isNat(X) a!6220!6220isNatList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatList(Y)) a!6220!6220length(cons(X, Y)) >? a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(Y), isNat(X)), Y) mark(zeros) >? a!6220!6220zeros mark(cons(X, Y)) >? cons(mark(X), Y) mark(s(X)) >? s(mark(X)) a!6220!6220and(X, Y) >? and(X, Y) We orient these requirements with a polynomial interpretation in the natural numbers. The following interpretation satisfies the requirements: 0 = 2 a!6220!6220U11 = \y0y1.y0 + y1 a!6220!6220and = \y0y1.y0 + y1 a!6220!6220isNat = \y0.2y0 a!6220!6220isNatList = \y0.2y0 a!6220!6220length = \y0.y0 a!6220!6220zeros = 2 and = \y0y1.y0 + y1 cons = \y0y1.y0 + 3y1 isNat = \y0.y0 isNatList = \y0.y0 mark = \y0.2 + y0 s = \y0.y0 tt = 2 zeros = 0 Using this interpretation, the requirements translate to: [[a!6220!6220zeros]] = 2 >= 2 = [[cons(0, zeros)]] [[a!6220!6220U11(tt, _x0)]] = 2 + x0 >= 2 + x0 = [[s(a!6220!6220length(mark(_x0)))]] [[a!6220!6220isNat(0)]] = 4 > 2 = [[tt]] [[a!6220!6220isNat(s(_x0))]] = 2x0 >= 2x0 = [[a!6220!6220isNat(_x0)]] [[a!6220!6220isNatList(cons(_x0, _x1))]] = 2x0 + 6x1 >= x1 + 2x0 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatList(_x1))]] [[a!6220!6220length(cons(_x0, _x1))]] = x0 + 3x1 >= x0 + 3x1 = [[a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(_x1), isNat(_x0)), _x1)]] [[mark(zeros)]] = 2 >= 2 = [[a!6220!6220zeros]] [[mark(cons(_x0, _x1))]] = 2 + x0 + 3x1 >= 2 + x0 + 3x1 = [[cons(mark(_x0), _x1)]] [[mark(s(_x0))]] = 2 + x0 >= 2 + x0 = [[s(mark(_x0))]] [[a!6220!6220and(_x0, _x1)]] = x0 + x1 >= x0 + x1 = [[and(_x0, _x1)]] We can thus remove the following rules: a!6220!6220isNat(0) => tt We use rule removal, following [Kop12, Theorem 2.23]. This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): a!6220!6220zeros >? cons(0, zeros) a!6220!6220U11(tt, X) >? s(a!6220!6220length(mark(X))) a!6220!6220isNat(s(X)) >? a!6220!6220isNat(X) a!6220!6220isNatList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatList(Y)) a!6220!6220length(cons(X, Y)) >? a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(Y), isNat(X)), Y) mark(zeros) >? a!6220!6220zeros mark(cons(X, Y)) >? cons(mark(X), Y) mark(s(X)) >? s(mark(X)) a!6220!6220and(X, Y) >? and(X, Y) We orient these requirements with a polynomial interpretation in the natural numbers. The following interpretation satisfies the requirements: 0 = 0 a!6220!6220U11 = \y0y1.y0 + 2y1 a!6220!6220and = \y0y1.y0 + y1 a!6220!6220isNat = \y0.2y0 a!6220!6220isNatList = \y0.y0 a!6220!6220length = \y0.1 + y0 a!6220!6220zeros = 0 and = \y0y1.y0 + y1 cons = \y0y1.2y0 + 3y1 isNat = \y0.y0 isNatList = \y0.y0 mark = \y0.y0 s = \y0.2y0 tt = 3 zeros = 0 Using this interpretation, the requirements translate to: [[a!6220!6220zeros]] = 0 >= 0 = [[cons(0, zeros)]] [[a!6220!6220U11(tt, _x0)]] = 3 + 2x0 > 2 + 2x0 = [[s(a!6220!6220length(mark(_x0)))]] [[a!6220!6220isNat(s(_x0))]] = 4x0 >= 2x0 = [[a!6220!6220isNat(_x0)]] [[a!6220!6220isNatList(cons(_x0, _x1))]] = 2x0 + 3x1 >= x1 + 2x0 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatList(_x1))]] [[a!6220!6220length(cons(_x0, _x1))]] = 1 + 2x0 + 3x1 > x0 + 3x1 = [[a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(_x1), isNat(_x0)), _x1)]] [[mark(zeros)]] = 0 >= 0 = [[a!6220!6220zeros]] [[mark(cons(_x0, _x1))]] = 2x0 + 3x1 >= 2x0 + 3x1 = [[cons(mark(_x0), _x1)]] [[mark(s(_x0))]] = 2x0 >= 2x0 = [[s(mark(_x0))]] [[a!6220!6220and(_x0, _x1)]] = x0 + x1 >= x0 + x1 = [[and(_x0, _x1)]] We can thus remove the following rules: a!6220!6220U11(tt, X) => s(a!6220!6220length(mark(X))) a!6220!6220length(cons(X, Y)) => a!6220!6220U11(a!6220!6220and(a!6220!6220isNatList(Y), isNat(X)), Y) We use rule removal, following [Kop12, Theorem 2.23]. This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): a!6220!6220zeros >? cons(0, zeros) a!6220!6220isNat(s(X)) >? a!6220!6220isNat(X) a!6220!6220isNatList(cons(X, Y)) >? a!6220!6220and(a!6220!6220isNat(X), isNatList(Y)) mark(zeros) >? a!6220!6220zeros mark(cons(X, Y)) >? cons(mark(X), Y) mark(s(X)) >? s(mark(X)) a!6220!6220and(X, Y) >? and(X, Y) We orient these requirements with a polynomial interpretation in the natural numbers. The following interpretation satisfies the requirements: 0 = 0 a!6220!6220and = \y0y1.y0 + y1 a!6220!6220isNat = \y0.y0 a!6220!6220isNatList = \y0.3 + 3y0 a!6220!6220zeros = 3 and = \y0y1.y0 + y1 cons = \y0y1.3 + y0 + y1 isNatList = \y0.y0 mark = \y0.3 + 3y0 s = \y0.3 + y0 zeros = 0 Using this interpretation, the requirements translate to: [[a!6220!6220zeros]] = 3 >= 3 = [[cons(0, zeros)]] [[a!6220!6220isNat(s(_x0))]] = 3 + x0 > x0 = [[a!6220!6220isNat(_x0)]] [[a!6220!6220isNatList(cons(_x0, _x1))]] = 12 + 3x0 + 3x1 > x0 + x1 = [[a!6220!6220and(a!6220!6220isNat(_x0), isNatList(_x1))]] [[mark(zeros)]] = 3 >= 3 = [[a!6220!6220zeros]] [[mark(cons(_x0, _x1))]] = 12 + 3x0 + 3x1 > 6 + x1 + 3x0 = [[cons(mark(_x0), _x1)]] [[mark(s(_x0))]] = 12 + 3x0 > 6 + 3x0 = [[s(mark(_x0))]] [[a!6220!6220and(_x0, _x1)]] = x0 + x1 >= x0 + x1 = [[and(_x0, _x1)]] We can thus remove the following rules: a!6220!6220isNat(s(X)) => a!6220!6220isNat(X) a!6220!6220isNatList(cons(X, Y)) => a!6220!6220and(a!6220!6220isNat(X), isNatList(Y)) mark(cons(X, Y)) => cons(mark(X), Y) mark(s(X)) => s(mark(X)) We use rule removal, following [Kop12, Theorem 2.23]. This gives the following requirements (possibly using Theorems 2.25 and 2.26 in [Kop12]): a!6220!6220zeros >? cons(0, zeros) mark(zeros) >? a!6220!6220zeros a!6220!6220and(X, Y) >? and(X, Y) We orient these requirements with a polynomial interpretation in the natural numbers. The following interpretation satisfies the requirements: 0 = 0 a!6220!6220and = \y0y1.3 + y0 + y1 a!6220!6220zeros = 3 and = \y0y1.y0 + y1 cons = \y0y1.y0 + y1 mark = \y0.3 + 3y0 zeros = 1 Using this interpretation, the requirements translate to: [[a!6220!6220zeros]] = 3 > 1 = [[cons(0, zeros)]] [[mark(zeros)]] = 6 > 3 = [[a!6220!6220zeros]] [[a!6220!6220and(_x0, _x1)]] = 3 + x0 + x1 > x0 + x1 = [[and(_x0, _x1)]] We can thus remove the following rules: a!6220!6220zeros => cons(0, zeros) mark(zeros) => a!6220!6220zeros a!6220!6220and(X, Y) => and(X, Y) All rules were succesfully removed. Thus, termination of the original system has been reduced to termination of the beta-rule, which is well-known to hold. +++ Citations +++ [Kop12] C. Kop. Higher Order Termination. PhD Thesis, 2012.