
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 $\overrightarrow{a}=(\cos \frac {2}{3}\pi,\sin \frac {2}{3}\pi)$, $\overrightarrow{OA}= \overrightarrow{a}- \overrightarrow{b}$, $\overrightarrow{OB}= \overrightarrow{a}+ \overrightarrow{b}$. If $\triangle OAB$ is an isosceles right triangle with $O$ as the right angle vertex, calculate the area of $\triangle OAB$.

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