
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 sets A and B are subsets of the universal set U={1, 2, 3, 4}, and the complement of A union B with respect to U is $\{4\}$, i.e., $\complement_U(A \cup B) = \{4\}$, and B={1, 2}, find $A \cap (\complement_U B)$.

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