
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 function 
$$
f(x)= 
\begin{cases} 
m \log_{2017}x + 3 \sin x, & x>0 \\
\log_{2017}(-x) + n \sin x, & x<0 
\end{cases}
$$
is an even function, find the value of $m-n$.

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