
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 sets \( A=\{x^2, 2x-1, -4\} \) and \( B=\{x-5, 1-x, 9\} \), with the intersection of \( B \) and \( A \) being \( B \cap A = \{9\} \), find the union of \( A \) and \( B \), \( A \cup B \).

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