
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
\[2014·Northern Jiangsu Cities Mock Test\] Given set $A = \{x \mid |x-a| \leq 1\}$, and set $B = \{x \mid x^2 - 5x + 4 \geq 0\}$, if $A \cap B = \emptyset$, then the range of the real number $a$ is \_\_\_\_\_\_\_\_.

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