
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
Regarding the following statements:  
① If the domain of the function $y=2^x$ is $\{x|x\leq0\}$, then its range is $\{y|y\leq1\}$.  
② If the domain of the function $y=\frac{1}{x}$ is $\{x|x>2\}$, then its range is $\{y|y\leq\frac{1}{2}\}$.  
③ If the range of the function $y=x^2$ is $\{y|0\leq y\leq4\}$, then its domain must be $\{x|-2\leq x\leq2\}$.  
④ If the range of the function $y=\log_2x$ is $\{y|y\leq3\}$, then its domain is $\{x|0<x\leq8\}$.  
Among these, the incorrect statement(s) is/are \_\_\_\_\_\_ . (Note: Fill in the sequence number(s) of the statement(s) you consider incorrect.)

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