
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 sets $A = \{x | x^2 - 4x - 5 \leq 0\}$,  
$B = \{x | x^2 - 2x - m < 0\}$.  
(1) When $m = 3$, find $A \cap \complement_{\mathbb{R}} B$;  
(2) If $A \cap B = \{x | -1 \leq x < 4\}$, find the value of the real number $m$.

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