
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
Given the circle C: $(x-a)^2+y^2=4$ (where $a$ is a constant, $a \in \mathbb{R}$), determine the range of values for the real number $a$ such that the circle does not pass through the second quadrant.

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