/export/starexec/sandbox/solver/bin/starexec_run_complexity /export/starexec/sandbox/benchmark/theBenchmark.koat /export/starexec/sandbox/output/output_files


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WORST_CASE(Omega(n^1), O(n^1))
proof of /export/starexec/sandbox/benchmark/theBenchmark.koat
# AProVE Commit ID: 794c25de1cacf0d048858bcd21c9a779e1221865 marcel 20200619 unpublished dirty


The runtime complexity of the given CpxIntTrs could be proven to be BOUNDS(n^1, n^1).

(0) CpxIntTrs
(1) Koat Proof [FINISHED, 17 ms]
(2) BOUNDS(1, n^1)
(3) Loat Proof [FINISHED, 105 ms]
(4) BOUNDS(n^1, INF)


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(0)
Obligation:
Complexity Int TRS consisting of the following rules:
sumto(A, B) -> Com_1(end(A, B)) :|: A >= B + 1
sumto(A, B) -> Com_1(sumto(A + 1, B)) :|: B >= A
start(A, B) -> Com_1(sumto(A, B)) :|: TRUE

The start-symbols are:[start_2]


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(1) Koat Proof (FINISHED)
YES(?, Ar_0 + Ar_1 + 3)



Initial complexity problem:

1:	T:

		(Comp: ?, Cost: 1)    sumto(Ar_0, Ar_1) -> Com_1(end(Ar_0, Ar_1)) [ Ar_0 >= Ar_1 + 1 ]

		(Comp: ?, Cost: 1)    sumto(Ar_0, Ar_1) -> Com_1(sumto(Ar_0 + 1, Ar_1)) [ Ar_1 >= Ar_0 ]

		(Comp: ?, Cost: 1)    start(Ar_0, Ar_1) -> Com_1(sumto(Ar_0, Ar_1))

		(Comp: 1, Cost: 0)    koat_start(Ar_0, Ar_1) -> Com_1(start(Ar_0, Ar_1)) [ 0 <= 0 ]

	start location:	koat_start

	leaf cost:	0



Repeatedly propagating knowledge in problem 1 produces the following problem:

2:	T:

		(Comp: ?, Cost: 1)    sumto(Ar_0, Ar_1) -> Com_1(end(Ar_0, Ar_1)) [ Ar_0 >= Ar_1 + 1 ]

		(Comp: ?, Cost: 1)    sumto(Ar_0, Ar_1) -> Com_1(sumto(Ar_0 + 1, Ar_1)) [ Ar_1 >= Ar_0 ]

		(Comp: 1, Cost: 1)    start(Ar_0, Ar_1) -> Com_1(sumto(Ar_0, Ar_1))

		(Comp: 1, Cost: 0)    koat_start(Ar_0, Ar_1) -> Com_1(start(Ar_0, Ar_1)) [ 0 <= 0 ]

	start location:	koat_start

	leaf cost:	0



A polynomial rank function with

	Pol(sumto) = 1

	Pol(end) = 0

	Pol(start) = 1

	Pol(koat_start) = 1

orients all transitions weakly and the transition

	sumto(Ar_0, Ar_1) -> Com_1(end(Ar_0, Ar_1)) [ Ar_0 >= Ar_1 + 1 ]

strictly and produces the following problem:

3:	T:

		(Comp: 1, Cost: 1)    sumto(Ar_0, Ar_1) -> Com_1(end(Ar_0, Ar_1)) [ Ar_0 >= Ar_1 + 1 ]

		(Comp: ?, Cost: 1)    sumto(Ar_0, Ar_1) -> Com_1(sumto(Ar_0 + 1, Ar_1)) [ Ar_1 >= Ar_0 ]

		(Comp: 1, Cost: 1)    start(Ar_0, Ar_1) -> Com_1(sumto(Ar_0, Ar_1))

		(Comp: 1, Cost: 0)    koat_start(Ar_0, Ar_1) -> Com_1(start(Ar_0, Ar_1)) [ 0 <= 0 ]

	start location:	koat_start

	leaf cost:	0



A polynomial rank function with

	Pol(sumto) = -V_1 + V_2 + 1

	Pol(end) = -V_1 + V_2

	Pol(start) = -V_1 + V_2 + 1

	Pol(koat_start) = -V_1 + V_2 + 1

orients all transitions weakly and the transition

	sumto(Ar_0, Ar_1) -> Com_1(sumto(Ar_0 + 1, Ar_1)) [ Ar_1 >= Ar_0 ]

strictly and produces the following problem:

4:	T:

		(Comp: 1, Cost: 1)                  sumto(Ar_0, Ar_1) -> Com_1(end(Ar_0, Ar_1)) [ Ar_0 >= Ar_1 + 1 ]

		(Comp: Ar_0 + Ar_1 + 1, Cost: 1)    sumto(Ar_0, Ar_1) -> Com_1(sumto(Ar_0 + 1, Ar_1)) [ Ar_1 >= Ar_0 ]

		(Comp: 1, Cost: 1)                  start(Ar_0, Ar_1) -> Com_1(sumto(Ar_0, Ar_1))

		(Comp: 1, Cost: 0)                  koat_start(Ar_0, Ar_1) -> Com_1(start(Ar_0, Ar_1)) [ 0 <= 0 ]

	start location:	koat_start

	leaf cost:	0



Complexity upper bound Ar_0 + Ar_1 + 3



Time: 0.022 sec (SMT: 0.019 sec)


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(2)
BOUNDS(1, n^1)

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(3) Loat Proof (FINISHED)


### Pre-processing the ITS problem ###



Initial linear ITS problem

   Start location: start

      0: sumto -> end : [ A>=1+B ], cost: 1

      1: sumto -> sumto : A'=1+A, [ B>=A ], cost: 1

      2: start -> sumto : [], cost: 1



Checking for constant complexity:

   The following rule is satisfiable with cost >= 1, yielding constant complexity:

      2: start -> sumto : [], cost: 1



Removed unreachable and leaf rules:

   Start location: start

      1: sumto -> sumto : A'=1+A, [ B>=A ], cost: 1

      2: start -> sumto : [], cost: 1



### Simplification by acceleration and chaining ###



Accelerating simple loops of location 0.

   Accelerating the following rules:

      1: sumto -> sumto : A'=1+A, [ B>=A ], cost: 1



   Accelerated rule 1 with metering function 1-A+B, yielding the new rule 3.

   Removing the simple loops: 1.



Accelerated all simple loops using metering functions (where possible):

   Start location: start

      3: sumto -> sumto : A'=1+B, [ B>=A ], cost: 1-A+B

      2: start -> sumto : [], cost: 1



Chained accelerated rules (with incoming rules):

   Start location: start

      2: start -> sumto : [], cost: 1

      4: start -> sumto : A'=1+B, [ B>=A ], cost: 2-A+B



Removed unreachable locations (and leaf rules with constant cost):

   Start location: start

      4: start -> sumto : A'=1+B, [ B>=A ], cost: 2-A+B



### Computing asymptotic complexity ###



Fully simplified ITS problem

   Start location: start

      4: start -> sumto : A'=1+B, [ B>=A ], cost: 2-A+B



Computing asymptotic complexity for rule 4

   Solved the limit problem by the following transformations:

      Created initial limit problem:

      2-A+B (+), 1-A+B (+/+!) [not solved]



      removing all constraints (solved by SMT)

      resulting limit problem: [solved]



      applying transformation rule (C) using substitution {A==0,B==n}

      resulting limit problem:

      [solved]



   Solution:

      A / 0

      B / n

   Resulting cost 2+n has complexity: Poly(n^1)



Found new complexity Poly(n^1).



Obtained the following overall complexity (w.r.t. the length of the input n):

   Complexity:  Poly(n^1)

   Cpx degree:  1

   Solved cost: 2+n

   Rule cost:   2-A+B

   Rule guard:  [ B>=A ]



WORST_CASE(Omega(n^1),?)


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(4)
BOUNDS(n^1, INF)