
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
If line $a$ is not parallel to plane $\alpha$, then the following conclusions are not valid:  
① All lines within plane $\alpha$ are skew to line $a$;  
② There are no lines within plane $\alpha$ that are parallel to line $a$;  
③ Line $a$ has a common point with plane $\alpha$;  
④ All lines within plane $\alpha$ intersect with line $a$.

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