
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
Let $I = \{2, 4, a^2 - a - 3\}$ and $A = \{4, 1 - a\}$. If the complement of set $A$ relative to $I$, denoted as $\complement_{I}A$, is $\{-1\}$, determine the value of $a$.

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