
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
Electives 4-5: Special Topics in Inequalities  
Given the function $f(x) = |x-3| + |x+1|$,  
(I) Find the range of $x$ for which the inequality $f(x) < 6$ holds;  
(II) if there exists an $x \in \mathbb{R}$ such that $f(x) < a$, determine the range of real numbers $a$.

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