
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
Four objects A, B, C, and D start moving from the same point at the same time in the same direction. Their distances as functions of time $x (x\geqslant 0)$ are given by $f_1(x) = 2^x - 1$, $f_2(x) = x^3$, $f_3(x) = x$, and $f_4(x) = \log_2(x+1)$, respectively. The following conclusions are drawn:
1. When $x > 1$, A is in the lead;
2. When $x > 1$, B is in the lead;
3. When $0 < x < 1$, D is in the lead, but when $x > 1$, D is at the end;
4. C can never be in the lead or at the end;
5. If they continue moving, A will eventually be in the lead.

Identify the correct conclusions by filling in the blanks with their numbers (only score if all correct conclusions are identified without over- or under-selection).

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