
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
Let $\Delta ABC$ have its three internal angles $A$, $B$, $C$ opposite to sides $a$, $b$, $c$ respectively, and the area of $\Delta ABC$, denoted as $S$, satisfies $4\sqrt{3}S = a^{2} + b^{2} - c^{2}$.

   (1) Find the value of angle $C$;

   (2) Find the range of values for $\sin B - \cos A$.

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