
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 two lines l₁: x + (1 + a)y + a - 1 = 0, l₂: ax + 2y + 6 = 0.
(1) Find the value of a if l₁ is parallel to l₂.
(2) Find the value of a if l₁ is perpendicular to l₂.

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