
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 ellipse $C$: $\frac{x^2}{a^2}+\frac{y^2}{b^2}=1(a>b>0)$ have left and right foci $F_{1}$, $F_{2}$, and line $l$ passing through point $F_{1}$. If the point $P$, which is the symmetric point of $F_{2}$ with respect to line $l$, lies exactly on ellipse $C$, and $\overrightarrow{F_1P} \cdot \overrightarrow{F_1F_2} = \frac{1}{2}a^2$, find the eccentricity of $C$.

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