(0) Obligation:

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

dbl(S(0), S(0)) → S(S(S(S(0))))
unsafe(S(x)) → dbl(unsafe(x), 0)
unsafe(0) → 0
dbl(0, y) → y

Rewrite Strategy: INNERMOST

(1) CpxTrsMatchBoundsTAProof (EQUIVALENT transformation)

A linear upper bound on the runtime complexity of the TRS R could be shown with a Match-Bound[TAB_LEFTLINEAR,TAB_NONLEFTLINEAR] (for contructor-based start-terms) of 1.

The compatible tree automaton used to show the Match-Boundedness (for constructor-based start-terms) is represented by:
final states : [1, 2]
transitions:
S0(0) → 0
00() → 0
dbl0(0, 0) → 1
unsafe0(0) → 2
01() → 5
S1(5) → 4
S1(4) → 3
S1(3) → 3
S1(3) → 1
unsafe1(0) → 6
01() → 7
dbl1(6, 7) → 2
01() → 2
dbl1(6, 7) → 6
01() → 6
0 → 1
7 → 2
7 → 6

(2) BOUNDS(1, n^1)