
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 a constant $a > 0$, the function $f(x)=\ln (1+ax)- \dfrac {2x}{x+2}$.
- (I) Discuss the monotonicity of $f(x)$ on the interval $(0,+\infty)$;
- (II) If $f(x)$ has two extreme points $x_{1}$ and $x_{2}$, and $f(x_{1})+f(x_{2}) > 0$, find the range of values for $a$.

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