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

(0) Obligation:

Runtime Complexity TRS:
The TRS R consists of the following rules:

fac(s(x)) → *(fac(p(s(x))), s(x))
p(s(0)) → 0
p(s(s(x))) → s(p(s(x)))

Rewrite Strategy: INNERMOST

(1) RenamingProof (EQUIVALENT transformation)

Renamed function symbols to avoid clashes with predefined symbol.

(2) Obligation:

Runtime Complexity Relative TRS:
The TRS R consists of the following rules:

fac(s(x)) → *'(fac(p(s(x))), s(x))
p(s(0')) → 0'
p(s(s(x))) → s(p(s(x)))

S is empty.
Rewrite Strategy: INNERMOST

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

Infered types.

(4) Obligation:

Innermost TRS:
Rules:
fac(s(x)) → *'(fac(p(s(x))), s(x))
p(s(0')) → 0'
p(s(s(x))) → s(p(s(x)))

Types:
fac :: s:0' → *'
s :: s:0' → s:0'
*' :: *' → s:0' → *'
p :: s:0' → s:0'
0' :: s:0'
hole_*'1_0 :: *'
hole_s:0'2_0 :: s:0'
gen_*'3_0 :: Nat → *'
gen_s:0'4_0 :: Nat → s:0'

(5) OrderProof (LOWER BOUND(ID) transformation)

Heuristically decided to analyse the following defined symbols:
fac, p

They will be analysed ascendingly in the following order:
p < fac

(6) Obligation:

Innermost TRS:
Rules:
fac(s(x)) → *'(fac(p(s(x))), s(x))
p(s(0')) → 0'
p(s(s(x))) → s(p(s(x)))

Types:
fac :: s:0' → *'
s :: s:0' → s:0'
*' :: *' → s:0' → *'
p :: s:0' → s:0'
0' :: s:0'
hole_*'1_0 :: *'
hole_s:0'2_0 :: s:0'
gen_*'3_0 :: Nat → *'
gen_s:0'4_0 :: Nat → s:0'

Generator Equations:
gen_*'3_0(0) ⇔ hole_*'1_0
gen_*'3_0(+(x, 1)) ⇔ *'(gen_*'3_0(x), 0')
gen_s:0'4_0(0) ⇔ 0'
gen_s:0'4_0(+(x, 1)) ⇔ s(gen_s:0'4_0(x))

The following defined symbols remain to be analysed:
p, fac

They will be analysed ascendingly in the following order:
p < fac

(7) RewriteLemmaProof (LOWER BOUND(ID) transformation)

Proved the following rewrite lemma:
p(gen_s:0'4_0(+(1, n6_0))) → gen_s:0'4_0(n6_0), rt ∈ Ω(1 + n6₀)

Induction Base:
p(gen_s:0'4_0(+(1, 0))) →_R^Ω(1)
0'

Induction Step:
p(gen_s:0'4_0(+(1, +(n6_0, 1)))) →_R^Ω(1)
s(p(s(gen_s:0'4_0(n6_0)))) →_IH
s(gen_s:0'4_0(c7_0))

We have rt ∈ Ω(n¹) and sz ∈ O(n). Thus, we have irc_R ∈ Ω(n).

(8) Complex Obligation (BEST)

(9) Obligation:

Innermost TRS:
Rules:
fac(s(x)) → *'(fac(p(s(x))), s(x))
p(s(0')) → 0'
p(s(s(x))) → s(p(s(x)))

Types:
fac :: s:0' → *'
s :: s:0' → s:0'
*' :: *' → s:0' → *'
p :: s:0' → s:0'
0' :: s:0'
hole_*'1_0 :: *'
hole_s:0'2_0 :: s:0'
gen_*'3_0 :: Nat → *'
gen_s:0'4_0 :: Nat → s:0'

Lemmas:
p(gen_s:0'4_0(+(1, n6_0))) → gen_s:0'4_0(n6_0), rt ∈ Ω(1 + n6₀)

Generator Equations:
gen_*'3_0(0) ⇔ hole_*'1_0
gen_*'3_0(+(x, 1)) ⇔ *'(gen_*'3_0(x), 0')
gen_s:0'4_0(0) ⇔ 0'
gen_s:0'4_0(+(x, 1)) ⇔ s(gen_s:0'4_0(x))

The following defined symbols remain to be analysed:
fac

(10) NoRewriteLemmaProof (LOWER BOUND(ID) transformation)

Could not prove a rewrite lemma for the defined symbol fac.

(11) Obligation:

Innermost TRS:
Rules:
fac(s(x)) → *'(fac(p(s(x))), s(x))
p(s(0')) → 0'
p(s(s(x))) → s(p(s(x)))

Types:
fac :: s:0' → *'
s :: s:0' → s:0'
*' :: *' → s:0' → *'
p :: s:0' → s:0'
0' :: s:0'
hole_*'1_0 :: *'
hole_s:0'2_0 :: s:0'
gen_*'3_0 :: Nat → *'
gen_s:0'4_0 :: Nat → s:0'

Lemmas:
p(gen_s:0'4_0(+(1, n6_0))) → gen_s:0'4_0(n6_0), rt ∈ Ω(1 + n6₀)

Generator Equations:
gen_*'3_0(0) ⇔ hole_*'1_0
gen_*'3_0(+(x, 1)) ⇔ *'(gen_*'3_0(x), 0')
gen_s:0'4_0(0) ⇔ 0'
gen_s:0'4_0(+(x, 1)) ⇔ s(gen_s:0'4_0(x))

No more defined symbols left to analyse.

(12) LowerBoundsProof (EQUIVALENT transformation)

The lowerbound Ω(n¹) was proven with the following lemma:
p(gen_s:0'4_0(+(1, n6_0))) → gen_s:0'4_0(n6_0), rt ∈ Ω(1 + n6₀)

(13) BOUNDS(n^1, INF)

(14) Obligation:

Innermost TRS:
Rules:
fac(s(x)) → *'(fac(p(s(x))), s(x))
p(s(0')) → 0'
p(s(s(x))) → s(p(s(x)))

Types:
fac :: s:0' → *'
s :: s:0' → s:0'
*' :: *' → s:0' → *'
p :: s:0' → s:0'
0' :: s:0'
hole_*'1_0 :: *'
hole_s:0'2_0 :: s:0'
gen_*'3_0 :: Nat → *'
gen_s:0'4_0 :: Nat → s:0'

Lemmas:
p(gen_s:0'4_0(+(1, n6_0))) → gen_s:0'4_0(n6_0), rt ∈ Ω(1 + n6₀)

Generator Equations:
gen_*'3_0(0) ⇔ hole_*'1_0
gen_*'3_0(+(x, 1)) ⇔ *'(gen_*'3_0(x), 0')
gen_s:0'4_0(0) ⇔ 0'
gen_s:0'4_0(+(x, 1)) ⇔ s(gen_s:0'4_0(x))

No more defined symbols left to analyse.

(15) LowerBoundsProof (EQUIVALENT transformation)

The lowerbound Ω(n¹) was proven with the following lemma:
p(gen_s:0'4_0(+(1, n6_0))) → gen_s:0'4_0(n6_0), rt ∈ Ω(1 + n6₀)

(16) BOUNDS(n^1, INF)