
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 $C: x^2 + y^2 - 2ax + 2ay + 2a^2 + 2a - 1 = 0$ and the line $l: x - y - 1 = 0$ have a common point, the range of values for $a$ is ____.

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