
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 $U=R$, $A=\{x\in R | 2 \leqslant x < 5\}$, $B=\{x\in R | 3 \leqslant x \leqslant 7\}$, calculate:
- $(1) A \cup B$
- $(2) (\complement _{U}A) \cup (\complement _{U}B)$.

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