
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
Determine the value of $m - n$ if the equation $x^{4-3|m|}+y^{3|n|}=2009$ is a linear equation in two variables $x$ and $y$, given that $mn < 0$ and $0 < m + n \leq 3$.

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