
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 the random variable $\xi$ follow the normal distribution $N(0,1)$, and denote $\phi(x) = P(\xi < x)$. Consider the following statements:  
① $\phi(0) = 0.5$; ② $\phi(1) = 1 - \phi(-1)$; ③ $\phi(|\xi| < 3) = 2\phi(3) - 1$; ④ $\phi(|\xi| > 3) = 1 - \phi(3)$. The correct statement(s) is/are.

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