
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 a differentiable function $y=f(x)$ defined on $\mathbb{R}$, its derivative is denoted as $f'(x)$, satisfying $f'(x) < f(x)$. Also, $y=f(x+2)$ is an even function, and $f(4)=1$. Then, the solution set of the inequality $f(x) < e^x$ is ______.

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