
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 hyperbola $\frac{x^{2}}{a^{2}} - \frac{y^{2}}{b^{2}} = 1 (a > 0, b > 0)$ with left and right foci $F\_1$ and $F\_2$, respectively. A line passing through $F\_2$ intersects the right branch of the hyperbola at points $A$ and $B$. If triangle $ABF\_1$ is an isosceles right triangle with a right angle at vertex $A$, and $e$ is the eccentricity of the hyperbola, then $e^2 =$ $\_\_\_\_\_\_\_\_$.

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