
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 for any point \( M(x, y) \) on the curve \( y = f(x) \), a tangent \( L \) is drawn at \( M \), and there exists another point \( N(x_1, y_1) \) on the curve (distinct from \( M \)) such that a tangent \( L_1 \) at \( N \) can be drawn parallel to \( L \), then the curve \( y = f(x) \) is said to possess "parallelicity". Among the following four curves:  
1. \( y = x^3 - x \)  
2. \( y = x + \frac{1}{x} \)  
3. \( y = \sin x \)  
4. \( y = (x-2)^2 + \ln x \)  

the curves that have parallelicity are __________. (List all curve numbers that satisfy the condition)

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