
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 $f(x)= \begin{cases} -x^{2}+ax,x\leqslant 2 \\ ax-4,x > 2 \end{cases}$, if there exist $x_{1}$, $x_{2}\in R$ and $x_{1}\neq x_{2}$, such that $f(x_{1})=f(x_{2})$ holds, then the range of the real number $a$ is _____ .

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