
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 function $f(x)=\log_a (1-x) + \log_a (x+3)$ $(a>0,\ a \neq 1)$,  
(1) Determine the domain and range of the function $f(x)$.  
(2) If the function $f(x)$ has a minimum value of $-2$, find the value of $a$.

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