
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 functions $f(x)=\ln(x)$, $g(x)=\frac{1}{2}ax^2+2x$ $(a\neq 0)$. If $h(x)$ has a decreasing interval on $[1,4]$, find the range of $a$.

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