
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 set $A=\left\{{x|{\frac{4}{{x+1}}>1}}\right\}$, set $B=\left\{{x|x^2+2x-a^2+2a<0, a\in\mathbb{R}\right\}$ ($a<1$).<br /> (1) Find set A;<br /> (2) If x∈B is a necessary condition for x∈A, find the range of real number a.

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