
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 following four propositions: ① There is exactly one line through a point outside a plane that is parallel to the plane; ② There is exactly one line through a point outside a plane that is perpendicular to the plane; ③ If two parallel planes intersect with a third plane, then the two intersection lines are parallel; ④ If two planes are perpendicular to each other, then a line passing through a point in the first plane and perpendicular to the second plane must lie within the first plane. The sequence numbers of all true propositions are __________.

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