
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
For which values of the parameter \( a \) does the system of equations

\[ 
\left\{ 
\begin{array}{l} 
x^{2}+y^{2}+z^{2}+2y=0 \\ 
x+ay+az-a=0 
\end{array} 
\right. 
\]

have a unique solution?

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