
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
Express the following sets using an appropriate method.  
(1) The set of solutions to the equation $x^2-4=0$.  
(2) The set of prime numbers that satisfy the inequality $0<2x<18$.  
(3) The set of all even numbers.  
(4) The set of points in the fourth quadrant of the Cartesian coordinate plane.

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