
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 that points on line $l_{1}$ satisfy $ax+4y+6=0$, and points on line $l_{2}$ satisfy $\left( \frac {3}{4}a+1\right)x+ay- \frac {3}{2}=0$. Find:  
(Ⅰ) The value of $a$ when $l_{1}\parallel l_{2}$  
(Ⅱ) The value of $a$ when $l_{1}\perp l_{2}$.

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