
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
The function \( f \) is defined on the set of positive integers and satisfies:
\[ f(x)=\left\{\begin{array}{l}
n-3, \quad n \geqslant 1000 \\
f(f(n+5)), \quad 1 \leqslant n < 1000 .
\end{array}\right. \]
Find \( f(84) \).

Present the answer in LaTex format: \boxed{Your answer}
user