The Runtime Complexity (innermost) of the given CpxTRS could be proven to be BOUNDS(1, n^1).

(0) Obligation:

The Runtime Complexity (innermost) of the given CpxTRS could be proven to be BOUNDS(1, n^1).


The TRS R consists of the following rules:

h(f(x), y) → f(g(x, y))
g(x, y) → h(x, y)

Rewrite Strategy: INNERMOST

(1) TrsToWeightedTrsProof (BOTH BOUNDS(ID, ID) transformation)

Transformed TRS to weighted TRS

(2) Obligation:

The Runtime Complexity (innermost) of the given CpxWeightedTrs could be proven to be BOUNDS(1, n^1).


The TRS R consists of the following rules:

h(f(x), y) → f(g(x, y)) [1]
g(x, y) → h(x, y) [1]

Rewrite Strategy: INNERMOST

(3) TypeInferenceProof (BOTH BOUNDS(ID, ID) transformation)

Infered types.

(4) Obligation:

Runtime Complexity Weighted TRS with Types.
The TRS R consists of the following rules:

h(f(x), y) → f(g(x, y)) [1]
g(x, y) → h(x, y) [1]

The TRS has the following type information:

h :: f → a → f f :: f → f g :: f → a → f

Rewrite Strategy: INNERMOST

(5) CompletionProof (UPPER BOUND(ID) transformation)

The transformation into a RNTS is sound, since:

(a) The obligation is a constructor system where every type has a constant constructor,

(b) The following defined symbols do not have to be completely defined, as they can never occur inside other defined symbols:

h
g

(c) The following functions are completely defined:
none

Due to the following rules being added:
none

And the following fresh constants:

const, const1

(6) Obligation:

Runtime Complexity Weighted TRS where critical functions are completely defined. The underlying TRS is:

Runtime Complexity Weighted TRS with Types. The TRS R consists of the following rules: h(f(x), y) → f(g(x, y)) [1] g(x, y) → h(x, y) [1] The TRS has the following type information: h :: f → a → f f :: f → f g :: f → a → f const :: f const1 :: a Rewrite Strategy: INNERMOST

(7) NarrowingProof (BOTH BOUNDS(ID, ID) transformation)

Narrowed the inner basic terms of all right-hand sides by a single narrowing step.

(8) Obligation:

Runtime Complexity Weighted TRS where critical functions are completely defined. The underlying TRS is:

Runtime Complexity Weighted TRS with Types. The TRS R consists of the following rules: h(f(x), y) → f(g(x, y)) [1] g(x, y) → h(x, y) [1] The TRS has the following type information: h :: f → a → f f :: f → f g :: f → a → f const :: f const1 :: a Rewrite Strategy: INNERMOST

(9) CpxTypedWeightedTrsToRntsProof (UPPER BOUND(ID) transformation)

Transformed the TRS into an over-approximating RNTS by (improved) Size Abstraction.
The constant constructors are abstracted as follows:

const => 0
const1 => 0

(10) Obligation:

Complexity RNTS consisting of the following rules:

g(z, z') -{ 1 }→ h(x, y) :|: x >= 0, y >= 0, z = x, z' = y
h(z, z') -{ 1 }→ 1 + g(x, y) :|: x >= 0, y >= 0, z = 1 + x, z' = y

(11) SimplificationProof (BOTH BOUNDS(ID, ID) transformation)

Simplified the RNTS by moving equalities from the constraints into the right-hand sides.

(12) Obligation:

Complexity RNTS consisting of the following rules:

g(z, z') -{ 1 }→ h(z, z') :|: z >= 0, z' >= 0
h(z, z') -{ 1 }→ 1 + g(z - 1, z') :|: z - 1 >= 0, z' >= 0

(13) CpxRntsAnalysisOrderProof (BOTH BOUNDS(ID, ID) transformation)

Found the following analysis order by SCC decomposition:

{ h, g }

(14) Obligation:

Complexity RNTS consisting of the following rules:

g(z, z') -{ 1 }→ h(z, z') :|: z >= 0, z' >= 0
h(z, z') -{ 1 }→ 1 + g(z - 1, z') :|: z - 1 >= 0, z' >= 0

Function symbols to be analyzed: {h,g}

(15) IntTrsBoundProof (UPPER BOUND(ID) transformation)

Computed SIZE bound using CoFloCo for: h
after applying outer abstraction to obtain an ITS,
resulting in: O(1) with polynomial bound: 0

Computed SIZE bound using CoFloCo for: g
after applying outer abstraction to obtain an ITS,
resulting in: O(1) with polynomial bound: 0

(16) Obligation:

Complexity RNTS consisting of the following rules:

g(z, z') -{ 1 }→ h(z, z') :|: z >= 0, z' >= 0
h(z, z') -{ 1 }→ 1 + g(z - 1, z') :|: z - 1 >= 0, z' >= 0

Function symbols to be analyzed: {h,g}
Previous analysis results are:

h: runtime: ?, size: O(1) [0] g: runtime: ?, size: O(1) [0]

(17) IntTrsBoundProof (UPPER BOUND(ID) transformation)

Computed RUNTIME bound using PUBS for: h
after applying outer abstraction to obtain an ITS,
resulting in: O(n¹) with polynomial bound: 2·z

Computed RUNTIME bound using CoFloCo for: g
after applying outer abstraction to obtain an ITS,
resulting in: O(n¹) with polynomial bound: 1 + 2·z

(18) Obligation:

Complexity RNTS consisting of the following rules:

g(z, z') -{ 1 }→ h(z, z') :|: z >= 0, z' >= 0
h(z, z') -{ 1 }→ 1 + g(z - 1, z') :|: z - 1 >= 0, z' >= 0

Function symbols to be analyzed:
Previous analysis results are:

h: runtime: O(n1) [2·z], size: O(1) [0] g: runtime: O(n1) [1 + 2·z], size: O(1) [0]

(19) FinalProof (EQUIVALENT transformation)

Computed overall runtime complexity

(20) BOUNDS(1, n^1)