- #1

- 8

- 0

## Homework Statement

Find a simple DFA (i.e. deterministic finite automaton) that accepts all natural numbers

*n*for which

*n*mod 3 = 0.

*Hint:*A natural number is divisible by 3 if its checksum (or sum of digits) is divisible by 3.

## Homework Equations

## The Attempt at a Solution

I'm not sure how the hint can help for this question, even though I know what it means. For instance,

*137 = 1+3+7 = 11 mod 3 ≠ 0*etc.

Any other useful hints or suggestions would be great. Thanks. :)