
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
The function \( f(x, y) \) satisfies the following conditions for all non-negative integers:
1. \( f(0, y) = y + 1 \)
2. \( f(x + 1, 0) = f(x, 1) \)
3. \( f(x + 1, y + 1) = f(x, f(x + 1, y)) \)

Determine \( f(4, 1981) \).

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