
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
There are 10 pairs of different shoes mixed in a bag. If 4 shoes are randomly taken out, how many situations can occur for the following results:  
(1) None of the 4 shoes form a pair;  
(2) Exactly 2 pairs are formed among the 4 shoes;  
(3) Among the 4 shoes, there are 2 shoes forming a pair, and the other 2 do not form a pair.

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