
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
Define an odd function $f(x)$ on $\mathbb{R}$, where $f(x)=- \dfrac {2^{x}}{4^{x}+1}$ for $x < 0$.  
$(1)$ Find the expression for $f(x)$.  
$(2)$ If the inequality $\dfrac {2^{x}}{f(x)}-\lambda\cdot 2^{x}-2\geqslant 0$ holds for all $x\in(1,+\infty)$, find the range of the real number $\lambda$.

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