
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 a real number $a$ as a constant, and $U=\mathbb{R}$, let the set $A=\{x| \frac{x-3}{x+1} > 0\}$, $B=\{x|y= \sqrt{\log_{2}x-1}\}$, and $C=\{x|x^{2}-(4+a)x+4a \leq 0\}$.  
(1) Find $A \cap B$;  
(2) If $\complement_{U}A \subseteq C$, find the range of values for $a$.

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