
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
Among the propositions below, identify the correct ones. (Fill in the serial number)  
① If two points on a line $l$ are equidistant from a plane $\alpha$, then $l \parallel \alpha$;  
② If three points within a plane $\alpha$ which are not on the same line are equidistant from another plane $\beta$, then $\alpha \parallel \beta$;  
③ Two planes perpendicular to the same line are parallel;  
④ Two planes parallel to the same line are parallel;  
⑤ If lines $a$ and $b$ are skew, with $a \subset \alpha$, $b \parallel \alpha$, $b \subset \beta$, and $a \parallel \beta$, then $\alpha \parallel \beta$.

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