
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
In space,
   (1) If four points are not coplanar, then any three of these points are not collinear;
   (2) If two lines have no common points, then these two lines are skew lines.
              Among these two propositions, the one whose converse is true is __________ (fill in the serial number only).

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