
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. If a random variable $ξ$ follows a normal distribution $N(μ, σ^2)$ and $P(ξ < 2) = P(ξ > 6) = 0.15$, then $P(2 \leq ξ < 4) = 0.3$.
2. Let $a = \int_{0}^{1} (2x - e^x) \,dx$, then $a = 2 - e$.
3. The constant term in the expansion of the binomial $(\frac{1}{\sqrt{x}} - x^2)^{10}$ is 45.
4. Given $x \in (0,4]$, the probability that $\log_2 x \leq 1$ is 0.5.

Identify the true propositions by their numbers.

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