
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
The function $f(x)=\begin{cases} ax^{2}+x-1 & (x > 2) \\ -x+1 & (x\leqslant 2) \end{cases}$ is a monotonically decreasing function on $\mathbb{R}$, then the range of the real number $a$ is ______.

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