
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
Given a function $f(x)$ and its derivative $f'(x)$, if there exists $x_0$ such that $f(x_0) = f'(x_0)$, then $x_0$ is called a "clever value point" of $f(x)$. Among the following functions, those that have a "clever value point" are \_\_\_\_\_\_. (Write down all correct serial numbers)  
① $f(x) = x^2$  
② $f(x) = e^{-x}$  
③ $f(x) = \ln x$  
④ $f(x) = 2 + \sin x$  
⑤ $f(x) = x + \frac{1}{x}$．

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