
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 lines $l\_1$: $x+ay+6=0$ and $l\_2$: $(a-2)x+3y+2a=0$, the necessary and sufficient condition for $l\_1$ to be parallel to $l\_2$ is $a=$ _____ .

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