
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
Let non-zero vectors $\overrightarrow{a}$, $\overrightarrow{b}$, and $\overrightarrow{c}$ be in the following propositions: 
1. If $\overrightarrow{a}$ and $\overrightarrow{b}$ are collinear, then the line containing $\overrightarrow{a}$ and $\overrightarrow{b}$ is parallel;
2. If the lines containing $\overrightarrow{a}$ and $\overrightarrow{b}$ are skew lines, then $\overrightarrow{a}$ and $\overrightarrow{b}$ must not be coplanar;
3. If vectors $\overrightarrow{a}$, $\overrightarrow{b}$, and $\overrightarrow{c}$ are pairwise coplanar, then $\overrightarrow{a}$, $\overrightarrow{b}$, and $\overrightarrow{c}$ must also be coplanar;
4. Any vector $\overrightarrow{p}$ in space can always be uniquely represented as $\overrightarrow{p} = x\overrightarrow{a} + y\overrightarrow{b} + z\overrightarrow{c}$.

The incorrect proposition(s) is/are ______.

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