
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 the set of real numbers $\mathbb{R}$ be the universal set, $A=\{x|0\leq2x-1\leq5\}$, $B=\{x|x^2+a<0\}$.
1. When $a=-4$, find $A\cap B$ and $A\cup B$;
2. If $B\cap(\complement_{\mathbb{R}}A)=B$, find the range of the real number $a$.

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