
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 statements about algorithms, the correct ones are:  
 ．  
① The algorithm for solving a certain type of problem is unique; ② An algorithm must stop after a finite number of steps; ③ Each step of an algorithm must be clear, without ambiguity or vagueness; ④ An algorithm always produces a definite result after execution.

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