(0) Obligation:
Runtime Complexity TRS:
The TRS R consists of the following rules:
lt(0, s(x)) → true
lt(x, 0) → false
lt(s(x), s(y)) → lt(x, y)
logarithm(x) → ifa(lt(0, x), x)
ifa(true, x) → help(x, 1)
ifa(false, x) → logZeroError
help(x, y) → ifb(lt(y, x), x, y)
ifb(true, x, y) → help(half(x), s(y))
ifb(false, x, y) → y
half(0) → 0
half(s(0)) → 0
half(s(s(x))) → s(half(x))
Rewrite Strategy: INNERMOST
(1) CpxTrsToCdtProof (BOTH BOUNDS(ID, ID) transformation)
Converted CpxTRS to CDT
(2) Obligation:
Complexity Dependency Tuples Problem
Rules:
lt(0, s(z0)) → true
lt(z0, 0) → false
lt(s(z0), s(z1)) → lt(z0, z1)
logarithm(z0) → ifa(lt(0, z0), z0)
ifa(true, z0) → help(z0, 1)
ifa(false, z0) → logZeroError
help(z0, z1) → ifb(lt(z1, z0), z0, z1)
ifb(true, z0, z1) → help(half(z0), s(z1))
ifb(false, z0, z1) → z1
half(0) → 0
half(s(0)) → 0
half(s(s(z0))) → s(half(z0))
Tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
LOGARITHM(z0) → c3(IFA(lt(0, z0), z0), LT(0, z0))
IFA(true, z0) → c4(HELP(z0, 1))
HELP(z0, z1) → c6(IFB(lt(z1, z0), z0, z1), LT(z1, z0))
IFB(true, z0, z1) → c7(HELP(half(z0), s(z1)), HALF(z0))
HALF(s(s(z0))) → c11(HALF(z0))
S tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
LOGARITHM(z0) → c3(IFA(lt(0, z0), z0), LT(0, z0))
IFA(true, z0) → c4(HELP(z0, 1))
HELP(z0, z1) → c6(IFB(lt(z1, z0), z0, z1), LT(z1, z0))
IFB(true, z0, z1) → c7(HELP(half(z0), s(z1)), HALF(z0))
HALF(s(s(z0))) → c11(HALF(z0))
K tuples:none
Defined Rule Symbols:
lt, logarithm, ifa, help, ifb, half
Defined Pair Symbols:
LT, LOGARITHM, IFA, HELP, IFB, HALF
Compound Symbols:
c2, c3, c4, c6, c7, c11
(3) CdtKnowledgeProof (EQUIVALENT transformation)
The following tuples could be moved from S to K by knowledge propagation:
LOGARITHM(z0) → c3(IFA(lt(0, z0), z0), LT(0, z0))
IFA(true, z0) → c4(HELP(z0, 1))
IFA(true, z0) → c4(HELP(z0, 1))
(4) Obligation:
Complexity Dependency Tuples Problem
Rules:
lt(0, s(z0)) → true
lt(z0, 0) → false
lt(s(z0), s(z1)) → lt(z0, z1)
logarithm(z0) → ifa(lt(0, z0), z0)
ifa(true, z0) → help(z0, 1)
ifa(false, z0) → logZeroError
help(z0, z1) → ifb(lt(z1, z0), z0, z1)
ifb(true, z0, z1) → help(half(z0), s(z1))
ifb(false, z0, z1) → z1
half(0) → 0
half(s(0)) → 0
half(s(s(z0))) → s(half(z0))
Tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
LOGARITHM(z0) → c3(IFA(lt(0, z0), z0), LT(0, z0))
IFA(true, z0) → c4(HELP(z0, 1))
HELP(z0, z1) → c6(IFB(lt(z1, z0), z0, z1), LT(z1, z0))
IFB(true, z0, z1) → c7(HELP(half(z0), s(z1)), HALF(z0))
HALF(s(s(z0))) → c11(HALF(z0))
S tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
HELP(z0, z1) → c6(IFB(lt(z1, z0), z0, z1), LT(z1, z0))
IFB(true, z0, z1) → c7(HELP(half(z0), s(z1)), HALF(z0))
HALF(s(s(z0))) → c11(HALF(z0))
K tuples:
LOGARITHM(z0) → c3(IFA(lt(0, z0), z0), LT(0, z0))
IFA(true, z0) → c4(HELP(z0, 1))
Defined Rule Symbols:
lt, logarithm, ifa, help, ifb, half
Defined Pair Symbols:
LT, LOGARITHM, IFA, HELP, IFB, HALF
Compound Symbols:
c2, c3, c4, c6, c7, c11
(5) CdtNarrowingProof (BOTH BOUNDS(ID, ID) transformation)
Use narrowing to replace
LOGARITHM(
z0) →
c3(
IFA(
lt(
0,
z0),
z0),
LT(
0,
z0)) by
LOGARITHM(s(z0)) → c3(IFA(true, s(z0)), LT(0, s(z0)))
LOGARITHM(0) → c3(IFA(false, 0), LT(0, 0))
LOGARITHM(x0) → c3
(6) Obligation:
Complexity Dependency Tuples Problem
Rules:
lt(0, s(z0)) → true
lt(z0, 0) → false
lt(s(z0), s(z1)) → lt(z0, z1)
logarithm(z0) → ifa(lt(0, z0), z0)
ifa(true, z0) → help(z0, 1)
ifa(false, z0) → logZeroError
help(z0, z1) → ifb(lt(z1, z0), z0, z1)
ifb(true, z0, z1) → help(half(z0), s(z1))
ifb(false, z0, z1) → z1
half(0) → 0
half(s(0)) → 0
half(s(s(z0))) → s(half(z0))
Tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
IFA(true, z0) → c4(HELP(z0, 1))
HELP(z0, z1) → c6(IFB(lt(z1, z0), z0, z1), LT(z1, z0))
IFB(true, z0, z1) → c7(HELP(half(z0), s(z1)), HALF(z0))
HALF(s(s(z0))) → c11(HALF(z0))
LOGARITHM(s(z0)) → c3(IFA(true, s(z0)), LT(0, s(z0)))
LOGARITHM(0) → c3(IFA(false, 0), LT(0, 0))
LOGARITHM(x0) → c3
S tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
HELP(z0, z1) → c6(IFB(lt(z1, z0), z0, z1), LT(z1, z0))
IFB(true, z0, z1) → c7(HELP(half(z0), s(z1)), HALF(z0))
HALF(s(s(z0))) → c11(HALF(z0))
K tuples:
LOGARITHM(z0) → c3(IFA(lt(0, z0), z0), LT(0, z0))
IFA(true, z0) → c4(HELP(z0, 1))
Defined Rule Symbols:
lt, logarithm, ifa, help, ifb, half
Defined Pair Symbols:
LT, IFA, HELP, IFB, HALF, LOGARITHM
Compound Symbols:
c2, c4, c6, c7, c11, c3, c3
(7) CdtLeafRemovalProof (ComplexityIfPolyImplication transformation)
Removed 2 leading nodes:
LOGARITHM(s(z0)) → c3(IFA(true, s(z0)), LT(0, s(z0)))
IFA(true, z0) → c4(HELP(z0, 1))
Removed 2 trailing nodes:
LOGARITHM(x0) → c3
LOGARITHM(0) → c3(IFA(false, 0), LT(0, 0))
(8) Obligation:
Complexity Dependency Tuples Problem
Rules:
lt(0, s(z0)) → true
lt(z0, 0) → false
lt(s(z0), s(z1)) → lt(z0, z1)
logarithm(z0) → ifa(lt(0, z0), z0)
ifa(true, z0) → help(z0, 1)
ifa(false, z0) → logZeroError
help(z0, z1) → ifb(lt(z1, z0), z0, z1)
ifb(true, z0, z1) → help(half(z0), s(z1))
ifb(false, z0, z1) → z1
half(0) → 0
half(s(0)) → 0
half(s(s(z0))) → s(half(z0))
Tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
HELP(z0, z1) → c6(IFB(lt(z1, z0), z0, z1), LT(z1, z0))
IFB(true, z0, z1) → c7(HELP(half(z0), s(z1)), HALF(z0))
HALF(s(s(z0))) → c11(HALF(z0))
S tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
HELP(z0, z1) → c6(IFB(lt(z1, z0), z0, z1), LT(z1, z0))
IFB(true, z0, z1) → c7(HELP(half(z0), s(z1)), HALF(z0))
HALF(s(s(z0))) → c11(HALF(z0))
K tuples:none
Defined Rule Symbols:
lt, logarithm, ifa, help, ifb, half
Defined Pair Symbols:
LT, HELP, IFB, HALF
Compound Symbols:
c2, c6, c7, c11
(9) CdtNarrowingProof (BOTH BOUNDS(ID, ID) transformation)
Use narrowing to replace
HELP(
z0,
z1) →
c6(
IFB(
lt(
z1,
z0),
z0,
z1),
LT(
z1,
z0)) by
HELP(s(z0), 0) → c6(IFB(true, s(z0), 0), LT(0, s(z0)))
HELP(0, z0) → c6(IFB(false, 0, z0), LT(z0, 0))
HELP(s(z1), s(z0)) → c6(IFB(lt(z0, z1), s(z1), s(z0)), LT(s(z0), s(z1)))
HELP(x0, x1) → c6
(10) Obligation:
Complexity Dependency Tuples Problem
Rules:
lt(0, s(z0)) → true
lt(z0, 0) → false
lt(s(z0), s(z1)) → lt(z0, z1)
logarithm(z0) → ifa(lt(0, z0), z0)
ifa(true, z0) → help(z0, 1)
ifa(false, z0) → logZeroError
help(z0, z1) → ifb(lt(z1, z0), z0, z1)
ifb(true, z0, z1) → help(half(z0), s(z1))
ifb(false, z0, z1) → z1
half(0) → 0
half(s(0)) → 0
half(s(s(z0))) → s(half(z0))
Tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
IFB(true, z0, z1) → c7(HELP(half(z0), s(z1)), HALF(z0))
HALF(s(s(z0))) → c11(HALF(z0))
HELP(s(z0), 0) → c6(IFB(true, s(z0), 0), LT(0, s(z0)))
HELP(0, z0) → c6(IFB(false, 0, z0), LT(z0, 0))
HELP(s(z1), s(z0)) → c6(IFB(lt(z0, z1), s(z1), s(z0)), LT(s(z0), s(z1)))
HELP(x0, x1) → c6
S tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
IFB(true, z0, z1) → c7(HELP(half(z0), s(z1)), HALF(z0))
HALF(s(s(z0))) → c11(HALF(z0))
HELP(s(z0), 0) → c6(IFB(true, s(z0), 0), LT(0, s(z0)))
HELP(0, z0) → c6(IFB(false, 0, z0), LT(z0, 0))
HELP(s(z1), s(z0)) → c6(IFB(lt(z0, z1), s(z1), s(z0)), LT(s(z0), s(z1)))
HELP(x0, x1) → c6
K tuples:none
Defined Rule Symbols:
lt, logarithm, ifa, help, ifb, half
Defined Pair Symbols:
LT, IFB, HALF, HELP
Compound Symbols:
c2, c7, c11, c6, c6
(11) CdtLeafRemovalProof (ComplexityIfPolyImplication transformation)
Removed 1 leading nodes:
HELP(s(z0), 0) → c6(IFB(true, s(z0), 0), LT(0, s(z0)))
Removed 2 trailing nodes:
HELP(0, z0) → c6(IFB(false, 0, z0), LT(z0, 0))
HELP(x0, x1) → c6
(12) Obligation:
Complexity Dependency Tuples Problem
Rules:
lt(0, s(z0)) → true
lt(z0, 0) → false
lt(s(z0), s(z1)) → lt(z0, z1)
logarithm(z0) → ifa(lt(0, z0), z0)
ifa(true, z0) → help(z0, 1)
ifa(false, z0) → logZeroError
help(z0, z1) → ifb(lt(z1, z0), z0, z1)
ifb(true, z0, z1) → help(half(z0), s(z1))
ifb(false, z0, z1) → z1
half(0) → 0
half(s(0)) → 0
half(s(s(z0))) → s(half(z0))
Tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
IFB(true, z0, z1) → c7(HELP(half(z0), s(z1)), HALF(z0))
HALF(s(s(z0))) → c11(HALF(z0))
HELP(s(z1), s(z0)) → c6(IFB(lt(z0, z1), s(z1), s(z0)), LT(s(z0), s(z1)))
S tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
IFB(true, z0, z1) → c7(HELP(half(z0), s(z1)), HALF(z0))
HALF(s(s(z0))) → c11(HALF(z0))
HELP(s(z1), s(z0)) → c6(IFB(lt(z0, z1), s(z1), s(z0)), LT(s(z0), s(z1)))
K tuples:none
Defined Rule Symbols:
lt, logarithm, ifa, help, ifb, half
Defined Pair Symbols:
LT, IFB, HALF, HELP
Compound Symbols:
c2, c7, c11, c6
(13) CdtNarrowingProof (BOTH BOUNDS(ID, ID) transformation)
Use narrowing to replace
IFB(
true,
z0,
z1) →
c7(
HELP(
half(
z0),
s(
z1)),
HALF(
z0)) by
IFB(true, 0, x1) → c7(HELP(0, s(x1)), HALF(0))
IFB(true, s(0), x1) → c7(HELP(0, s(x1)), HALF(s(0)))
IFB(true, s(s(z0)), x1) → c7(HELP(s(half(z0)), s(x1)), HALF(s(s(z0))))
IFB(true, x0, x1) → c7
(14) Obligation:
Complexity Dependency Tuples Problem
Rules:
lt(0, s(z0)) → true
lt(z0, 0) → false
lt(s(z0), s(z1)) → lt(z0, z1)
logarithm(z0) → ifa(lt(0, z0), z0)
ifa(true, z0) → help(z0, 1)
ifa(false, z0) → logZeroError
help(z0, z1) → ifb(lt(z1, z0), z0, z1)
ifb(true, z0, z1) → help(half(z0), s(z1))
ifb(false, z0, z1) → z1
half(0) → 0
half(s(0)) → 0
half(s(s(z0))) → s(half(z0))
Tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
HALF(s(s(z0))) → c11(HALF(z0))
HELP(s(z1), s(z0)) → c6(IFB(lt(z0, z1), s(z1), s(z0)), LT(s(z0), s(z1)))
IFB(true, 0, x1) → c7(HELP(0, s(x1)), HALF(0))
IFB(true, s(0), x1) → c7(HELP(0, s(x1)), HALF(s(0)))
IFB(true, s(s(z0)), x1) → c7(HELP(s(half(z0)), s(x1)), HALF(s(s(z0))))
IFB(true, x0, x1) → c7
S tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
HALF(s(s(z0))) → c11(HALF(z0))
HELP(s(z1), s(z0)) → c6(IFB(lt(z0, z1), s(z1), s(z0)), LT(s(z0), s(z1)))
IFB(true, 0, x1) → c7(HELP(0, s(x1)), HALF(0))
IFB(true, s(0), x1) → c7(HELP(0, s(x1)), HALF(s(0)))
IFB(true, s(s(z0)), x1) → c7(HELP(s(half(z0)), s(x1)), HALF(s(s(z0))))
IFB(true, x0, x1) → c7
K tuples:none
Defined Rule Symbols:
lt, logarithm, ifa, help, ifb, half
Defined Pair Symbols:
LT, HALF, HELP, IFB
Compound Symbols:
c2, c11, c6, c7, c7
(15) CdtLeafRemovalProof (BOTH BOUNDS(ID, ID) transformation)
Removed 3 trailing nodes:
IFB(true, x0, x1) → c7
IFB(true, 0, x1) → c7(HELP(0, s(x1)), HALF(0))
IFB(true, s(0), x1) → c7(HELP(0, s(x1)), HALF(s(0)))
(16) Obligation:
Complexity Dependency Tuples Problem
Rules:
lt(0, s(z0)) → true
lt(z0, 0) → false
lt(s(z0), s(z1)) → lt(z0, z1)
logarithm(z0) → ifa(lt(0, z0), z0)
ifa(true, z0) → help(z0, 1)
ifa(false, z0) → logZeroError
help(z0, z1) → ifb(lt(z1, z0), z0, z1)
ifb(true, z0, z1) → help(half(z0), s(z1))
ifb(false, z0, z1) → z1
half(0) → 0
half(s(0)) → 0
half(s(s(z0))) → s(half(z0))
Tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
HALF(s(s(z0))) → c11(HALF(z0))
HELP(s(z1), s(z0)) → c6(IFB(lt(z0, z1), s(z1), s(z0)), LT(s(z0), s(z1)))
IFB(true, s(s(z0)), x1) → c7(HELP(s(half(z0)), s(x1)), HALF(s(s(z0))))
S tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
HALF(s(s(z0))) → c11(HALF(z0))
HELP(s(z1), s(z0)) → c6(IFB(lt(z0, z1), s(z1), s(z0)), LT(s(z0), s(z1)))
IFB(true, s(s(z0)), x1) → c7(HELP(s(half(z0)), s(x1)), HALF(s(s(z0))))
K tuples:none
Defined Rule Symbols:
lt, logarithm, ifa, help, ifb, half
Defined Pair Symbols:
LT, HALF, HELP, IFB
Compound Symbols:
c2, c11, c6, c7
(17) CdtPolyRedPairProof (UPPER BOUND (ADD(O(n^1))) transformation)
Found a reduction pair which oriented the following tuples strictly. Hence they can be removed from S.
HELP(s(z1), s(z0)) → c6(IFB(lt(z0, z1), s(z1), s(z0)), LT(s(z0), s(z1)))
IFB(true, s(s(z0)), x1) → c7(HELP(s(half(z0)), s(x1)), HALF(s(s(z0))))
We considered the (Usable) Rules:
half(0) → 0
half(s(0)) → 0
half(s(s(z0))) → s(half(z0))
lt(0, s(z0)) → true
lt(z0, 0) → false
lt(s(z0), s(z1)) → lt(z0, z1)
And the Tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
HALF(s(s(z0))) → c11(HALF(z0))
HELP(s(z1), s(z0)) → c6(IFB(lt(z0, z1), s(z1), s(z0)), LT(s(z0), s(z1)))
IFB(true, s(s(z0)), x1) → c7(HELP(s(half(z0)), s(x1)), HALF(s(s(z0))))
The order we found is given by the following interpretation:
Polynomial interpretation :
POL(0) = 0
POL(HALF(x1)) = 0
POL(HELP(x1, x2)) = [1] + [2]x1
POL(IFB(x1, x2, x3)) = [2]x2
POL(LT(x1, x2)) = 0
POL(c11(x1)) = x1
POL(c2(x1)) = x1
POL(c6(x1, x2)) = x1 + x2
POL(c7(x1, x2)) = x1 + x2
POL(false) = 0
POL(half(x1)) = x1
POL(lt(x1, x2)) = 0
POL(s(x1)) = [1] + x1
POL(true) = 0
(18) Obligation:
Complexity Dependency Tuples Problem
Rules:
lt(0, s(z0)) → true
lt(z0, 0) → false
lt(s(z0), s(z1)) → lt(z0, z1)
logarithm(z0) → ifa(lt(0, z0), z0)
ifa(true, z0) → help(z0, 1)
ifa(false, z0) → logZeroError
help(z0, z1) → ifb(lt(z1, z0), z0, z1)
ifb(true, z0, z1) → help(half(z0), s(z1))
ifb(false, z0, z1) → z1
half(0) → 0
half(s(0)) → 0
half(s(s(z0))) → s(half(z0))
Tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
HALF(s(s(z0))) → c11(HALF(z0))
HELP(s(z1), s(z0)) → c6(IFB(lt(z0, z1), s(z1), s(z0)), LT(s(z0), s(z1)))
IFB(true, s(s(z0)), x1) → c7(HELP(s(half(z0)), s(x1)), HALF(s(s(z0))))
S tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
HALF(s(s(z0))) → c11(HALF(z0))
K tuples:
HELP(s(z1), s(z0)) → c6(IFB(lt(z0, z1), s(z1), s(z0)), LT(s(z0), s(z1)))
IFB(true, s(s(z0)), x1) → c7(HELP(s(half(z0)), s(x1)), HALF(s(s(z0))))
Defined Rule Symbols:
lt, logarithm, ifa, help, ifb, half
Defined Pair Symbols:
LT, HALF, HELP, IFB
Compound Symbols:
c2, c11, c6, c7
(19) CdtPolyRedPairProof (UPPER BOUND (ADD(O(n^2))) transformation)
Found a reduction pair which oriented the following tuples strictly. Hence they can be removed from S.
HALF(s(s(z0))) → c11(HALF(z0))
We considered the (Usable) Rules:
half(0) → 0
half(s(0)) → 0
half(s(s(z0))) → s(half(z0))
lt(0, s(z0)) → true
lt(z0, 0) → false
lt(s(z0), s(z1)) → lt(z0, z1)
And the Tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
HALF(s(s(z0))) → c11(HALF(z0))
HELP(s(z1), s(z0)) → c6(IFB(lt(z0, z1), s(z1), s(z0)), LT(s(z0), s(z1)))
IFB(true, s(s(z0)), x1) → c7(HELP(s(half(z0)), s(x1)), HALF(s(s(z0))))
The order we found is given by the following interpretation:
Polynomial interpretation :
POL(0) = 0
POL(HALF(x1)) = [3]x1
POL(HELP(x1, x2)) = [2] + x1 + x12
POL(IFB(x1, x2, x3)) = x2 + x22
POL(LT(x1, x2)) = 0
POL(c11(x1)) = x1
POL(c2(x1)) = x1
POL(c6(x1, x2)) = x1 + x2
POL(c7(x1, x2)) = x1 + x2
POL(false) = 0
POL(half(x1)) = x1
POL(lt(x1, x2)) = 0
POL(s(x1)) = [2] + x1
POL(true) = 0
(20) Obligation:
Complexity Dependency Tuples Problem
Rules:
lt(0, s(z0)) → true
lt(z0, 0) → false
lt(s(z0), s(z1)) → lt(z0, z1)
logarithm(z0) → ifa(lt(0, z0), z0)
ifa(true, z0) → help(z0, 1)
ifa(false, z0) → logZeroError
help(z0, z1) → ifb(lt(z1, z0), z0, z1)
ifb(true, z0, z1) → help(half(z0), s(z1))
ifb(false, z0, z1) → z1
half(0) → 0
half(s(0)) → 0
half(s(s(z0))) → s(half(z0))
Tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
HALF(s(s(z0))) → c11(HALF(z0))
HELP(s(z1), s(z0)) → c6(IFB(lt(z0, z1), s(z1), s(z0)), LT(s(z0), s(z1)))
IFB(true, s(s(z0)), x1) → c7(HELP(s(half(z0)), s(x1)), HALF(s(s(z0))))
S tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
K tuples:
HELP(s(z1), s(z0)) → c6(IFB(lt(z0, z1), s(z1), s(z0)), LT(s(z0), s(z1)))
IFB(true, s(s(z0)), x1) → c7(HELP(s(half(z0)), s(x1)), HALF(s(s(z0))))
HALF(s(s(z0))) → c11(HALF(z0))
Defined Rule Symbols:
lt, logarithm, ifa, help, ifb, half
Defined Pair Symbols:
LT, HALF, HELP, IFB
Compound Symbols:
c2, c11, c6, c7
(21) CdtPolyRedPairProof (UPPER BOUND (ADD(O(n^2))) transformation)
Found a reduction pair which oriented the following tuples strictly. Hence they can be removed from S.
LT(s(z0), s(z1)) → c2(LT(z0, z1))
We considered the (Usable) Rules:
half(0) → 0
half(s(0)) → 0
half(s(s(z0))) → s(half(z0))
lt(0, s(z0)) → true
lt(z0, 0) → false
lt(s(z0), s(z1)) → lt(z0, z1)
And the Tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
HALF(s(s(z0))) → c11(HALF(z0))
HELP(s(z1), s(z0)) → c6(IFB(lt(z0, z1), s(z1), s(z0)), LT(s(z0), s(z1)))
IFB(true, s(s(z0)), x1) → c7(HELP(s(half(z0)), s(x1)), HALF(s(s(z0))))
The order we found is given by the following interpretation:
Polynomial interpretation :
POL(0) = 0
POL(HALF(x1)) = [2]x1
POL(HELP(x1, x2)) = [2]x1 + [2]x12
POL(IFB(x1, x2, x3)) = [2]x22
POL(LT(x1, x2)) = [2]x2
POL(c11(x1)) = x1
POL(c2(x1)) = x1
POL(c6(x1, x2)) = x1 + x2
POL(c7(x1, x2)) = x1 + x2
POL(false) = 0
POL(half(x1)) = [1] + x1
POL(lt(x1, x2)) = 0
POL(s(x1)) = [2] + x1
POL(true) = 0
(22) Obligation:
Complexity Dependency Tuples Problem
Rules:
lt(0, s(z0)) → true
lt(z0, 0) → false
lt(s(z0), s(z1)) → lt(z0, z1)
logarithm(z0) → ifa(lt(0, z0), z0)
ifa(true, z0) → help(z0, 1)
ifa(false, z0) → logZeroError
help(z0, z1) → ifb(lt(z1, z0), z0, z1)
ifb(true, z0, z1) → help(half(z0), s(z1))
ifb(false, z0, z1) → z1
half(0) → 0
half(s(0)) → 0
half(s(s(z0))) → s(half(z0))
Tuples:
LT(s(z0), s(z1)) → c2(LT(z0, z1))
HALF(s(s(z0))) → c11(HALF(z0))
HELP(s(z1), s(z0)) → c6(IFB(lt(z0, z1), s(z1), s(z0)), LT(s(z0), s(z1)))
IFB(true, s(s(z0)), x1) → c7(HELP(s(half(z0)), s(x1)), HALF(s(s(z0))))
S tuples:none
K tuples:
HELP(s(z1), s(z0)) → c6(IFB(lt(z0, z1), s(z1), s(z0)), LT(s(z0), s(z1)))
IFB(true, s(s(z0)), x1) → c7(HELP(s(half(z0)), s(x1)), HALF(s(s(z0))))
HALF(s(s(z0))) → c11(HALF(z0))
LT(s(z0), s(z1)) → c2(LT(z0, z1))
Defined Rule Symbols:
lt, logarithm, ifa, help, ifb, half
Defined Pair Symbols:
LT, HALF, HELP, IFB
Compound Symbols:
c2, c11, c6, c7
(23) SIsEmptyProof (EQUIVALENT transformation)
The set S is empty
(24) BOUNDS(O(1), O(1))