
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 that point $(x, y)$ maps to $(x, x+y)$ under the mapping $f$, if point $(m, n)$ is the image of the point $(2, 1)$ under the mapping $f$, calculate the value of $m-n$.

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