
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 $f(x)$ be a function defined on $\mathbb{R}$ such that $f(x+1) = -f(x)$. When $0 \leq x \leq 1$, $f(x) = -|x - \frac{1}{2}| + \frac{1}{2}$. Find the value of $f\left(\frac{5}{2}\right) - f\left(\frac{99}{2}\right)$.

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